US20140371560A1

Movatterモバイル変換

Info

Publication number: US20140371560A1
Application number: US13/918,522
Authority: US
Inventors: James Etzkorn; Stephen O'Driscoll
Original assignee: Google LLC
Current assignee: Google LLC; Verily Life Sciences LLC
Priority date: 2013-06-14
Filing date: 2013-06-14
Publication date: 2014-12-18
Also published as: US20140371559A1; WO2014201268A1; US9332935B2

Abstract

Body-mountable devices and methods for embedding a structure in a body-mountable device are described. A body-mountable device includes a transparent polymer and a structure embedded in the transparent polymer. The transparent polymer defines a posterior side and an anterior side of the body-mountable device. The structure has an outer diameter and an inner diameter and includes a sensor configured to detect an analyte and an antenna. The antenna includes a plurality of conductive loops spaced apart from each other between the outer diameter and the inner diameter.

Description

BACKGROUND

Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.

A body-mountable device may be configured to monitor health-related information based on at least one analyte detected in a fluid of a user wearing the body-mountable device. For example, the body-mountable device may comprise an eye-mountable device that may be in the form of a contact lens that includes a sensor configured to detect the at least one analyte (e.g., glucose) in a tear film of a user wearing the eye-mountable device. The body-mountable device may also be configured to monitor various other types of health-related information.

SUMMARY

In one aspect, a body-mountable device is disclosed. An example body-mountable device includes: a transparent polymer, wherein the transparent polymer defines a posterior side and an anterior side of the body-mountable device; and a structure embedded in the transparent polymer, wherein the structure has an outer diameter and an inner diameter and includes a sensor configured to detect an analyte and an antenna, wherein the antenna includes a plurality of conductive loops spaced apart from each other between the outer diameter and the inner diameter.

These as well as other aspects, advantages, and alternatives, will become apparent to those of ordinary skill in the art by reading the following detailed description, with reference where appropriate to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a system that includes an eye-mountable device in wireless communication with an external reader, according to an example embodiment.

FIG. 2ais a top view of a structure, according to an example embodiment.

FIG. 2bis a side cross-section view of the structure shown inFIG. 2a, according to an example embodiment.

FIG. 3ais a top view of an eye-mountable device, according to an example embodiment.

FIG. 3bis a side view of the eye-mountable device shown inFIG. 3a, according to an example embodiment.

FIG. 3cis a side cross-section view of the eye-mountable device shown inFIG. 3awhile mounted to a corneal surface of an eye, according to an example embodiment.

FIG. 3dis a side cross-section view showing tear film layers surrounding the surfaces of the eye-mountable device mounted as shown inFIG. 3c, according to an example embodiment.

FIG. 4 is a top view of another structure, according to an example embodiment.

FIG. 5 is a top view of yet another structure, according to an example embodiment.

FIG. 6 is a flow chart illustrating a method, according to an example embodiment.

FIG. 7ais an illustration of formation of a first polymer layer, according to an example embodiment.

FIG. 7bis an illustration of positioning a structure on a first polymer layer, according to an example embodiment.

FIG. 7cis an illustration of a structure positioned on a first polymer layer, according to an example embodiment.

FIG. 7dis an illustration of conforming a structure positioned on a first polymer layer to a curvature of the first polymer layer, according to an example embodiment.

FIG. 7eis an illustration of formation of a second polymer layer, according to an example embodiment.

DETAILED DESCRIPTION

The following detailed description describes various features and functions of the disclosed systems and methods with reference to the accompanying figures. In the figures, similar symbols typically identify similar components, unless context dictates otherwise. The illustrative system and method embodiments described herein are not meant to be limiting. It will be readily understood that certain aspects of the disclosed systems and methods can be arranged and combined in a wide variety of different configurations, all of which are contemplated herein.

I. INTRODUCTION

A body-mountable device may include a transparent polymer and a structure embedded in the transparent polymer that has an outer diameter and an inner diameter. The transparent polymer defines a posterior side and an anterior side of the body-mountable device. The structure includes a sensor configured to detect an analyte and an antenna that includes a plurality of conductive loops spaced apart from each other between the outer diameter and the inner diameter. Beneficially, the plurality of conductive loops can reduce buckling of the structure (e.g., one or more protrusions from a surface of the structure) when it is bent to conform to a curvature of the transparent polymer.

As used throughout this disclosure, the anterior side of the body-mountable device refers to an outward-facing side of the body-mountable device, whereas the posterior side of the body-mountable device refers to an inward-facing side of the body-mountable device. In particular, when the body-mountable device comprises an eye-mountable device and the eye-mountable device is mounted on an eye of the user, the anterior side corresponds to a side of the eye-mountable device that is facing outward and thus not touching the eye of the user. Further, when the eye-mountable device is mounted on an eye of the user, the posterior side corresponds to a side of the eye-mountable device that is facing inward and thus touching the eye of the user.

II. EXAMPLE SYSTEMS AND DEVICES

A body-mountable device may be configured to monitor health-related information based on at least one analyte detected in a fluid of a user wearing the body-mountable device. An example body-mountable device that comprises an eye-mountable device that is configured to detect the at least one analyte in a tear film of a user wearing the eye-mountable device will now be described in greater detail.

FIG. 1 is a block diagram of asystem100 with an eye-mountable device110 in wireless communication with anexternal reader180, according to an example embodiment. The exposed regions of the eye-mountable device110 are made of apolymeric material120 formed to be contact-mounted to a corneal surface of an eye. In accordance with exemplary methods, thepolymeric material120 may comprise a first polymer layer and a second polymer layer.

Substrate

130 is embedded in thepolymeric material120 to provide a mounting surface for apower supply140, acontroller150,bio-interactive electronics160, and anantenna170. Thebio-interactive electronics160 are operated by thecontroller150. Thepower supply140 supplies operating voltages to thecontroller150 and/or thebio-interactive electronics160. Theantenna170 is operated by thecontroller150 to communicate information to and/or from the eye-mountable device110. Theantenna170, thecontroller150, thepower supply140, and thebio-interactive electronics160 can all be situated on the embeddedsubstrate130. Because the eye-mountable device110 includes electronics and is configured to be contact-mounted to an eye, it may also be referred to as an ophthalmic electronics platform.

To facilitate contact-mounting, thepolymeric material120 can have a concave surface configured to adhere (“mount”) to a moistened corneal surface (e.g., by capillary forces with a tear film coating the corneal surface). Additionally or alternatively, the eye-mountable device110 can be adhered by a vacuum force between the corneal surface and the polymeric material due to the concave curvature. While mounted with the concave surface against the eye, the anterior or outward-facing surface of thepolymeric material120 can have a convex curvature that is formed to not interfere with eye-lid motion while the eye-mountable device110 is mounted to the eye. For example, thepolymeric material120 can be a substantially transparent curved polymeric disk shaped similarly to a contact lens.

Thepolymeric material120 can include one or more bio-compatible materials, such as those employed for use in contact lenses or other ophthalmic applications involving direct contact with the corneal surface. Thepolymeric material120 can optionally be formed in part from such bio-compatible materials or can include an outer coating with such bio-compatible materials. Thepolymeric material120 can include materials configured to moisturize the corneal surface, such as hydrogels and the like. In some instances, thepolymeric material120 can be a deformable (“non-rigid”) material to enhance wearer comfort. In some instances, thepolymeric material120 can be shaped to provide a predetermined, vision-correcting optical power, such as can be provided by a contact lens.

Thesubstrate130 includes one or more surfaces suitable for mounting thebio-interactive electronics160, thecontroller150, thepower supply140, and theantenna170. Thesubstrate130 can be employed both as a mounting platform for chip-based circuitry (e.g., by flip-chip mounting) and/or as a platform for patterning conductive materials (e.g., gold, platinum, palladium, titanium, copper, aluminum, silver, metals, other conductive materials, combinations of these, etc.) to create electrodes, interconnects, antennae, etc. In some embodiments, substantially transparent conductive materials (e.g., indium tin oxide) can be patterned on thesubstrate130 to form circuitry, electrodes, etc. For example, theantenna170 can be formed by depositing a pattern of gold or another conductive material on thesubstrate130. Similarly, interconnects151,157 between thecontroller150 and thebio-interactive electronics160, and between thecontroller150 and theantenna170, respectively, can be formed by depositing suitable patterns of conductive materials on thesubstrate130. A combination of resists, masks, and deposition techniques can be employed to pattern materials on thesubstrate130.

Thesubstrate130 can be a relatively rigid polymeric material, such as polyethylene terephthalate (“PET”), paralyene, or another material sufficient to structurally support the circuitry and/or electronics within thepolymeric material120. The eye-mountable device110 can alternatively be arranged with a group of unconnected substrates rather than a single substrate. For example, thecontroller150 and a bio-sensor or other bio-interactive electronic component can be mounted to one substrate, while theantenna170 is mounted to another substrate and the two can be electrically connected via theinterconnects157.

In some embodiments, the bio-interactive electronics160 (and the substrate130) can be positioned away from a center of the eye-mountable device110 and thereby avoid interference with light transmission to the eye through the center of the eye-mountable device110. For example, where the eye-mountable device110 is shaped as a concave-curved disk, thesubstrate130 can be embedded around the periphery (e.g., near the outer circumference) of the disk. In some embodiments, the bio-interactive electronics160 (and the substrate130) can be positioned in a center region of the eye-mountable device110. Thebio-interactive electronics160 and/or thesubstrate130 can be substantially transparent to incoming visible light to mitigate interference with light transmission to the eye. Moreover, in some embodiments, thebio-interactive electronics160 can include apixel array164 that emits and/or transmits light to be perceived by the eye according to display driver instructions. Thus, thebio-interactive electronics160 can optionally be positioned in the center of the eye-mountable device so as to generate perceivable visual cues to a wearer of the eye-mountable device110, such as by displaying information via thepixel array164.

Thesubstrate130 can be shaped as a flattened ring with a radial width dimension sufficient to provide a mounting platform for the embedded electronics components. Thesubstrate130 can have a thickness sufficiently small to allow thesubstrate130 to be embedded in thepolymeric material120 without influencing the profile of the eye-mountable device110. Thesubstrate130 can have a thickness sufficiently large to provide structural stability suitable for supporting the electronics mounted thereon. For example, thesubstrate130 can be shaped as a ring with a 1 centimeter diameter, a radial thickness of approximately 1 millimeter, and a thickness of about 50 micrometers. Thesubstrate130 can optionally be aligned with the curvature of the anterior side of the eye-mountable device110.

Thepower supply140 is configured to harvest ambient energy to power thecontroller150 and thebio-interactive electronics160. For example, a radio-frequencyenergy harvesting antenna142 can capture energy from incident radio radiation. Additionally or alternatively, solar cell(s)144 (“photovoltaic cells”) can capture energy from incoming ultraviolet, visible, and/or infrared radiation. Furthermore, an inertial power scavenging system (not shown) can be included to capture energy from ambient vibrations. The energy-harvestingantenna142 can optionally be a dual-purpose antenna that is also used to communicate information to theexternal reader180. That is, the functions of theantenna170 and theenergy harvesting antenna142 can be accomplished with the same physical antenna.

A rectifier/regulator146 can be used to condition the captured energy to a stableDC supply voltage141 that is supplied to thecontroller150. For example, theenergy harvesting antenna142 can receive incident radio frequency radiation. Varying electrical signals on the leads of theenergy harvesting antenna142 are output to the rectifier/regulator146. The rectifier/regulator146 rectifies the varying electrical signals to a DC voltage and regulates the rectified DC voltage to a level suitable for operating thecontroller150. Additionally or alternatively, output voltage from the solar cell(s)144 can be regulated to a level suitable for operating thecontroller150. The rectifier/regulator146 can include one or more energy storage devices arranged to mitigate high frequency variations in the ambientenergy harvesting antenna142 and/or solar cell(s)144. For example, an energy storage device (e.g., capacitor, inductor, etc.) can be connected to the output of the rectifier/regulator146 so as to function as a low-pass filter.

Thecontroller150 is turned on when theDC supply voltage141 is provided to thecontroller150, and the logic in thecontroller150 operates thebio-interactive electronics160 and theantenna170. Thecontroller150 can include logic circuitry configured to operate thebio-interactive electronics160 so as to interact with a biological environment of the eye-mountable device110. The interaction could involve the use of one or more components, such as ananalyte bio-sensor162, inbio-interactive electronics160 to obtain input from the biological environment. Alternatively or additionally, the interaction could involve the use of one or more components, such as thepixel array164, to provide an output to the biological environment.

In one example, asensor interface module152 can be included for operating theanalyte bio-sensor162. Theanalyte bio-sensor162 can be, for example, an amperometric electrochemical sensor that includes a working electrode and a reference electrode. Application of an appropriate voltage between the working and reference electrodes can cause an analyte to undergo electrochemical reactions (e.g., reduction and/or oxidation reactions) at the working electrode to generate an amperometric current. The amperometric current can be dependent on the analyte concentration, and thus the amount of amperometric current can provide an indication of analyte concentration. In some embodiments, thesensor interface module152 can be a potentiostat configured to apply a voltage difference between the working and reference electrodes while measuring a current through the working electrode.

In some embodiments, at least a portion of thebio-interactive electronics160, thecontroller150, the power supply, and/or theantenna170 can be embedded in thesubstrate130. And, in some embodiments, at least a portion of the bio-interactive electronics160 (e.g., the analyte bio-sensor162) can be surrounded by thesubstrate130, except for a surface of the at least a portion of thebio-interactive electronics160 being exposed by an opening in thesubstrate130.

In some instances, a reagent can also be included to sensitize the electrochemical sensor to desired analytes. For example, a layer of glucose oxidase (“GOD”) can be situated around the working electrode to catalyze glucose into hydrogen peroxide (H₂O₂). The hydrogen peroxide can then be oxidized at the working electrode, which releases electrons to the working electrode, which generates a current.

H₂O₂→2H⁺+O₂+2e⁻
The current generated by either reduction or oxidation reactions can be approximately proportionate to the reaction rate. Further, the reaction rate can be dependent on the rate of analyte molecules reaching the electrochemical sensor electrodes to fuel the reduction or oxidation reactions, either directly or catalytically through a reagent. In a steady state, where analyte molecules flow and/or diffuse to the electrochemical sensor electrodes from a sampled region at approximately the same rate that additional analyte molecules diffuse to the sampled region from surrounding regions, the reaction rate can be approximately proportionate to the concentration of the analyte molecules. The current can thus provide an indication of the analyte concentration.
Thecontroller150 can optionally include adisplay driver module154 for operating apixel array164. Thepixel array164 can be an array of separately programmable light transmitting, light reflecting, and/or light emitting pixels arranged in rows and columns. The individual pixel circuits can optionally include liquid crystal technologies, microelectromechanical technologies, emissive diode technologies, etc. to selectively transmit, reflect, and/or emit light according to information from thedisplay driver module154. Such apixel array164 can also optionally include more than one color of pixels (e.g., red, green, and blue pixels) to render visual content in color. Thedisplay driver module154 can include, for example, one or more data lines providing programming information to the separately programmed pixels in thepixel array164 and one or more addressing lines for setting groups of pixels to receive such programming information. Such apixel array164 situated on the eye can also include one or more lenses to direct light from the pixel array to a focal plane perceivable by the eye.
Thecontroller150 can also include acommunication circuit156 for sending and/or receiving information via theantenna170. Thecommunication circuit156 can optionally include one or more oscillators, mixers, frequency injectors, etc. to modulate and/or demodulate information on a carrier frequency to be transmitted and/or received by theantenna170. In some examples, the eye-mountable device110 is configured to indicate an output from a bio-sensor by modulating an impedance of theantenna170 in a manner that is perceivable by theexternal reader180. For example, thecommunication circuit156 can cause variations in the amplitude, phase, and/or frequency of backscatter radiation from theantenna170, and such variations can be detected by theexternal reader180.
Thecontroller150 is connected to thebio-interactive electronics160 viainterconnects151. For example, where thecontroller150 includes logic elements implemented in an integrated circuit to form thesensor interface module152 and/ordisplay driver module154, a patterned conductive material (e.g., gold, platinum, palladium, titanium, copper, aluminum, silver, metals, combinations of these, etc.) can connect a terminal on the chip to thebio-interactive electronics160. Similarly, thecontroller150 is connected to theantenna170 viainterconnects157.
It is noted that the block diagram shown inFIG. 1 is described in connection with functional modules for convenience in description. However, embodiments of the eye-mountable device110 can be arranged with one or more of the functional modules (“sub-systems”) implemented in a single chip, integrated circuit, and/or physical feature. For example, while the rectifier/regulator146 is illustrated in thepower supply block140, the rectifier/regulator146 can be implemented in a chip that also includes the logic elements of thecontroller150 and/or other features of the embedded electronics in the eye-mountable device110. Thus, theDC supply voltage141 that is provided to thecontroller150 from thepower supply140 can be a supply voltage that is provided on a chip by rectifier and/or regulator components the same chip. That is, the functional blocks inFIG. 1 shown as thepower supply block140 andcontroller block150 need not be implemented as separated modules. Moreover, one or more of the functional modules described inFIG. 1 can be implemented by separately packaged chips electrically connected to one another.
Additionally or alternatively, theenergy harvesting antenna142 and theantenna170 can be implemented with the same physical antenna. For example, a loop antenna can both harvest incident radiation for power generation and communicate information via backscatter radiation.
Theexternal reader180 includes an antenna188 (or group of more than one antennae) to send and receivewireless signals171 to and from the eye-mountable device110. Theexternal reader180 also includes a computing system with aprocessor186 in communication with amemory182. Thememory182 is a non-transitory computer-readable medium that can include, without limitation, magnetic disks, optical disks, organic memory, and/or any other volatile (e.g., RAM) or non-volatile (e.g., ROM) storage system readable by theprocessor186. Thememory182 can include adata storage183 to store indications of data substrates, such as sensor readings (e.g., from the analyte bio-sensor162), program settings (e.g., to adjust behavior of the eye-mountable device110 and/or external reader180), etc. The memory can also includeprogram instructions184 for execution by theprocessor186 to cause the external reader to perform processes specified by theprogram instructions184. For example, theprogram instructions184 can causeexternal reader180 to provide a user interface that allows for retrieving information communicated from the eye-mountable device110 (e.g., sensor outputs from the analyte bio-sensor162). Theexternal reader180 can also include one or more hardware components for operating theantenna188 to send and receive the wireless signals171 to and from the eye-mountable device110. For example, oscillators, frequency injectors, encoders, decoders, amplifiers, filters, etc. can drive theantenna188 according to instructions from theprocessor186.
Theexternal reader180 can be a smart phone, digital assistant, or other portable computing device with wireless connectivity sufficient to provide thewireless communication link171. Theexternal reader180 can also be implemented as an antenna module that can be plugged into a portable computing device, such as in an example where thecommunication link171 operates at carrier frequencies not commonly employed in portable computing devices. In some instances, theexternal reader180 is a special-purpose device configured to be worn relatively near a wearer's eye to allow thewireless communication link171 to operate with a low power budget. For example, theexternal reader180 can be integrated in a piece of jewelry such as a necklace, earing, etc. or integrated in an article of clothing worn near the head, such as a hat, headband, etc.
In an example where the eye-mountable device110 includes ananalyte bio-sensor162, thesystem100 can be operated to monitor the analyte concentration in tear film on the surface of the eye. Thus, the eye-mountable device110 can be configured as a platform for an ophthalmic analyte bio-sensor. The tear film is an aqueous layer secreted from the lacrimal gland to coat the eye. The tear film is in contact with the blood supply through capillaries in the substrate of the eye and includes many biomarkers found in blood that are analyzed to characterize a person's health condition(s). For example, the tear film includes glucose, calcium, sodium, cholesterol, potassium, other biomarkers, etc. The biomarker concentrations in the tear film can be systematically different than the corresponding concentrations of the biomarkers in the blood, but a relationship between the two concentration levels can be established to map tear film biomarker concentration values to blood concentration levels. For example, the tear film concentration of glucose can be established (e.g., empirically determined) to be approximately one tenth the corresponding blood glucose concentration. Thus, measuring tear film analyte concentration levels provides a non-invasive technique for monitoring biomarker levels in comparison to blood sampling techniques performed by lancing a volume of blood to be analyzed outside a person's body. Moreover, the ophthalmic analyte bio-sensor platform disclosed here can be operated substantially continuously to enable real time monitoring of analyte concentrations.
To perform a reading with thesystem100 configured as a tear film analyte monitor, theexternal reader180 can emitradio frequency radiation171 that is harvested to power the eye-mountable device110 via thepower supply140. Radio frequency electrical signals captured by the energy harvesting antenna142 (and/or the antenna170) are rectified and/or regulated in the rectifier/regulator146 and a regulated DC supply voltage647 is provided to thecontroller150. Theradio frequency radiation171 thus turns on the electronic components within the eye-mountable device110. Once turned on, thecontroller150 operates theanalyte bio-sensor162 to measure an analyte concentration level. For example, thesensor interface module152 can apply a voltage between a working electrode and a reference electrode in theanalyte bio-sensor162 sufficient to cause the analyte to undergo an electrochemical reaction at the working electrode. The current through the working electrode can be measured to provide the sensor output indicative of the analyte concentration. Thecontroller150 can operate theantenna170 to communicate the sensor results back to the external reader180 (e.g., via the communication circuit156). The sensor result can be communicated by, for example, modulating an impedance of theantenna170 such that the modulation in impedance is detected by theexternal reader180. The modulation in antenna impedance can be detected by, for example, backscatter radiation from theantenna170.
In some embodiments, thesystem100 can operate to non-continuously (“intermittently”) supply energy to the eye-mountable device110 to power the on-board controller150 and thebio-interactive electronics160. For example,radio frequency radiation171 can be supplied to power the eye-mountable device110 long enough to carry out a tear film analyte concentration measurement and communicate the results. For example, the supplied radio frequency radiation can provide sufficient power to charge two electrodes to a potential sufficient to induce electrochemical reactions, measure the resulting amperometric current, and modulate the antenna impedance to adjust the backscatter radiation in a manner indicative of the measured current. In such an example, the suppliedradio frequency radiation171 can be considered an interrogation signal from theexternal reader180 to the eye-mountable device110 to request a measurement. By periodically interrogating the eye-mountable device110 (e.g., by supplyingradio frequency radiation171 to temporarily turn the device on) and storing the sensor results (e.g., via the data storage183), theexternal reader180 can accumulate a set of analyte concentration measurements over time without continuously powering the eye-mountable device110.
FIG. 2ais a top view of astructure230, according to an example embodiment. In particular, thestructure230 has anouter diameter232 and aninner diameter234 and includeselectronics240,electronics250, asensor260, and anantenna270 disposed thereon. Thestructure230 may take the form of or be similar in form to thesubstrate130.
Thestructure230 can have various sizes. For instance, the size of thestructure230 may depend on which analyte an eye-mountable device is configured to detect. In an example, thestructure230 has a maximum height of approximately 50 between 150 micrometers. Of course, other maximum heights of thestructure230 are possible as well.
In an example, thestructure230 has a height dimension of at least 50 micrometers. In other words, at some point of thestructure230, the height of thestructure230 may be at least 50 micrometers. In an example, this height dimension may correspond to a maximum height of thestructure230. In accordance with the present disclosure, the maximum height of thestructure230 corresponds to the height of thestructure230 at its highest point. For instance, in the example where thestructure230 comprises thesensor260 and theelectronics250, the height of thestructure230 may vary (and thus thestructure230 may have various height dimensions). For example, the height of thestructure230 may be higher at a point where theelectronics250 is mounted on thestructure230, whereas the height may be lower at a point where there is no chip on thestructure230. In such an example, the maximum height may correspond to the point where theelectronics250 is mounted on thestructure230.
Theouter diameter232 and theinner diameter234 could take various different forms in various different embodiments. In some embodiments, the outer diameter can have a length between 12.5 and 15 millimeters. Moreover, in some embodiments, the inner diameter can have a length greater than 8 millimeters. And other lengths of theouter diameter232 and/orinner diameter234 are possible as well.
Theelectronics240 and250 could be configured in a variety of ways. For example, theelectronics240 and/or theelectronics250 may be configured to operate thesensor260 and theantenna270. And, in such an example, theelectronics240 and/or theelectronics250 may be configured for wireless communication with an external reader, such as theexternal reader180. In some embodiments, theelectronics240 and theelectronics250 may provide a bias voltage for thesensor260 and adjust backscattered radio frequency (RF) that is proportional to a current that is passing through thesensor260.
Theelectronics240 and theelectronics250 could take various different forms in various different embodiments. In some embodiments, theelectronics240 and/or theelectronics250 can comprise a chip including one or more logical elements. Theelectronics240 and/or theelectronics250 may take the form of or be similar in form to thecontroller150.
Thesensor260 is configured to detect one or more analytes. Thesensor260 could take various different forms in various different embodiments. In some embodiments, thesensor260 can comprise a pair of electrodes, such as a working electrode and a reference electrode. Thesensor260 may take the form of or be similar in form to theanalyte bio-sensor162.
Theantenna270 is configured for communications and/or harvesting energy as described herein. Theantenna270 includes a plurality ofconductive loops272 spaced apart from each other between theouter diameter232 and theinner diameter234. In the illustrated example, the plurality ofconductive loops272 includes threeconductive loops272A,272B, and272C. However, in other examples, a plurality of conductive loops may include more than three conductive loops, such as five conductive loops, nine conductive loops, etc.
As shown inFIG. 2a, theconductive loops272A,272B, and272C are connected in parallel. With this arrangement, each of the conductive loops in the plurality ofconductive loops272 is electrically connected to theelectronics240, theelectronics250, and thesensor260 via afirst connection274 and asecond connection276. And theelectronics240, theelectronics250, and thesensor260 are electrically connected via thefirst connection274 and thesecond connection276. Thefirst connection274 and thesecond connection276 may take the form of or be similar in form to theinterconnects151 and157. Moreover, as shown inFIG. 2a, theconductive loops272A,272B, and272C are substantially concentric. The term “substantially concentric,” as used in this disclosure, refers to exactly concentric and/or one or more deviations from exactly concentric that do not significantly impact embedding a structure in a body-mountable device as described herein.
And as shown inFIG. 2a, theconductive loops272A,272B, and272C are spaced apart from each other between theouter diameter232 and theinner diameter234. In an example, theconductive loops272A,272B, and272C can be spaced apart from adjacent conductive loops by a distance between 100 to 200 micrometers. Other distances are possible as well.
In some embodiments, one of theconductive loops272A,272B, and272C can have a width of 333 micrometers. Other widths of theconductive loops272A,272B, and272C are possible as well. Moreover, in some embodiments, theconductive loops272A,272B, and272C can each have the same width (e.g., theconductive loops272A,272B, and272C can each have a width of 333 micrometers). However, in some embodiments, theconductive loops272A,272B, and272C might not have the same width.
Each conductive loop in the plurality ofconductive loops272 can comprise a respective metal layer disposed between respective polymer layers. With this arrangement, the polymer layers might block moisture from the metal layer.FIG. 2bis a side cross-section view of the structure shown inFIG. 2a, according to an example embodiment. As shown inFIG. 2b, theconductive loop272A comprises ametal layer280 disposed betweenpolymer layers282A and282B. The respective metal layers of theconductive loops272B and272C may take the form of or be similar in form to the to themetal layer280, and the respective polymer layers of theconductive loops272B and272C may take the form of or be similar in form to the polymer layers282A and282B.
In some embodiments, themetal layer280 can comprise gold or another conductive material that can be deposited on thestructure230, such as platinum, palladium, titanium, carbon, aluminum, copper, silver, and/or silver-chloride. And in at least one such embodiment, themetal layer280 can have a thickness between 5 and 30 micrometers. Other thicknesses of themetal layer280 are possible as well. In an example, themetal layer280 can be formed by a process that includes electroplating.
Moreover, in some embodiments, the polymer layers282A and282B can comprise a relatively rigid transparent polymer, such as PET or paralyene. And in at least one such embodiment, the polymer layers282A and282B can have a thickness between 10 and 50 micrometers, such as 15 micrometers. Other thicknesses of the polymer layers282A and282B are possible as well. In an example, the polymer layers282A and282B can be formed by a process that includes chemical vapor deposition.
In an example, the plurality ofconductive loops272 can be formed by a process that includes etching a portion of a metal layer disposed between polymer layers with an inductively coupled plasma, such as an oxygen plasma.
FIG. 3ais a top view of an eye-mountableelectronic device310.FIG. 3bis a side view of the eye-mountableelectronic device310 shown inFIG. 3a. It is noted that relative dimensions inFIGS. 3aand3bare not necessarily to scale, but have been rendered for purposes of explanation only in describing the arrangement of the eye-mountableelectronic device310. The eye-mountable device310 is formed of atransparent polymer320 shaped as a curved disk. Thetransparent polymer320 can be a substantially transparent material to allow incident light to be transmitted to the eye while the eye-mountable device310 is mounted to the eye. Thetransparent polymer320 can be a bio-compatible material similar to those employed to form vision correction and/or cosmetic contact lenses in optometry, such as PET, polymethyl methacrylate (“PMMA”), silicone hydrogels, combinations of these, etc. Thetransparent polymer320 could take the form of or be similar in form to thepolymeric material120.
Thetransparent polymer320 can be formed with one side having a posterior side326 (i.e., concave surface) suitable to fit over a corneal surface of an eye. The opposing side of the disk can have anterior side324 (i.e., convex surface) that does not interfere with eyelid motion while the eye-mountable device310 is mounted to the eye. A circularouter side edge328 connects theposterior side326 andanterior side324.
The eye-mountable device310 can have dimensions similar to a vision correction and/or cosmetic contact lenses, such as a diameter of approximately 1 centimeter, and a thickness of about 0.1 to about 0.5 millimeters. However, the diameter and thickness values are provided for explanatory purposes only. In some embodiments, the dimensions of the eye-mountable device310 can be selected according to the size and/or shape of the corneal surface and/or the scleral surface of the wearer's eye.
While the eye-mountable device310 is mounted in an eye, theanterior side324 faces outward to the ambient environment while theposterior side326 faces inward, toward the corneal surface. Theanterior side324 can therefore be considered an outer, top surface of the eye-mountable device310 whereas theposterior side326 can be considered an inner, bottom surface. The “top” view shown inFIG. 3ais facing theanterior side324.
Thestructure330 is embedded in thetransparent polymer320. Thesubstrate330 can be embedded to be situated along anouter periphery322 of thetransparent polymer320, away from acenter region321. Thestructure330 does not interfere with vision because it is too close to the eye to be in focus and is positioned away from thecenter region321 where incident light is transmitted to the light-sensing portions of the eye. Thestructure330 can take the form or be similar in form to thesubstrate130 and/or thestructure230.
Thestructure330 has anouter diameter332 and aninner diameter334 and includeselectronics340,electronics350, asensor360, and anantenna370 disposed thereon. Theouter diameter332 may take the form of or be similar in form to theouter diameter232, theinner diameter334 may take the form of or be similar in form to theinner diameter234, theelectronics340 may take the form of or be similar in form to thecontroller150 and/or theelectronics240, theelectronics350 may take the form or be similar in form to thecontroller150 and/or theelectronics250, and thesensor360 may take the form or be similar in form to thebio-analyte sensor162 and/or thesensor260.
Theantenna370 is configured for communications and/or harvesting energy, like theantenna270 is configured for communications and/or harvesting energy. Theantenna370 includes a plurality ofconductive loops372 spaced apart from each other between theouter diameter332 and theinner diameter334. In the illustrated example, the plurality ofconductive loops372 includes threeconductive loops372A,372B, and372C. However, in other examples, a plurality of conductive loops may include more than three conductive loops, such as five conductive loops, nine conductive loops, etc. When thestructure330 is embedded in thetransparent polymer320, theconductive loops372A,372B, and372C may move relative to each other.
Theconductive loops372A,372B, and372C can have an arrangement similar to an arrangement of theconductive loops272A,272B, and272C. As shown inFIGS. 3aand3b, theconductive loops372A,372B, and272C are connected in parallel. With this arrangement, each of the conductive loops in the plurality ofconductive loops372 is electrically connected to theelectronics340, theelectronics350, and thesensor360 via afirst connection374 and asecond connection376. And theelectronics340, theelectronics350, and thesensor360 are electrically connected via thefirst connection374 and thesecond connection376. Thefirst connection374 and thesecond connection376 may take the form of or be similar in form to thefirst connection274 and thesecond connection276 and/or theinterconnects151 and157. Moreover, as shown inFIGS. 3aand3b, theconductive loops372A,372B, and372C are substantially concentric. And as shown inFIGS. 3aand3b, theconductive loops372A,372B, and372C are spaced apart from each other between theouter diameter332 and theinner diameter334.
Theconductive loops372A,372B, and372C may have a width that is the same or similar to a width of theconductive loops272A,272B, and272C. Moreover, each of the conductive loops in the plurality ofconductive loops372 can comprise a respective metal layer disposed between respective polymer layers, like the conductive loops in the plurality ofconductive loops272 comprise a respective metal layer disposed between respective polymer layers. And the plurality ofconductive loops372 can be formed like the plurality ofconductive loops272 is formed.
In the illustrated example, the metal and polymer layers in each conductive loop in the plurality ofconductive loops372 are spaced apart from the metal and polymer layers in each adjacent conductive loop in the in the plurality ofconductive loops372. In some embodiments, thetransparent polymer320 can extend between adjacent conductive loops (e.g., theconductive loop372A and the conductive loop372B and/or the conductive loop372B and the conductive loop372C) in the plurality ofconductive loops372.
Moreover, in the illustrated example, the metal and polymer layers of conductive loop372B are spaced apart from the metal and polymer layers of adjacentconductive loop372A by afirst distance394, and the metal and polymer layers of conductive loop372B are spaced apart from the metal and polymer layers of adjacent conductive loop372C by asecond distance396. In an example, thefirst distance394 and thesecond distance396 can be between 100 to 200 micrometers. Other distances are possible as well.
Thefirst distance394 could be a different value than thesecond distance396. In some embodiments, thefirst distance394 can be greater (or less) than thesecond distance396. And thefirst distance394 and/or thesecond distance396 could vary. In some embodiments, thefirst distance394 can vary based on a rotational orientation of the conductive loop372B relative to theconductive loop372A and/or the conductive loop372C. Moreover, in some embodiments, thesecond distance396 can vary based on a rotational orientation of the conductive loop372B relative to the conductive loop372C and/or theconductive loop372A.
FIG. 3cis a side cross-section view of the eye-mountable310 while mounted to acorneal surface384 of aneye380, according to an example embodiment.FIG. 3dis a close-in side cross-section view enhanced to show tear film layers390,392 surrounding exposedsurfaces324,326 of the eye-mountable device310, according to an example embodiment. It is noted that relative dimensions inFIGS. 3cand3dare not necessarily to scale, but have been rendered for purposes of explanation only in describing the arrangement of the eye-mountableelectronic device310. For example, the total thickness of the eye-mountable device310 can be about 200 micrometers, while the thickness of the tear film layers390,392 can each be about 10 micrometers, although this ratio may not be reflected in the drawings. Some aspects are exaggerated to allow for illustration and facilitate explanation.
Theeye380 includes acornea382 that is covered by bringing theupper eyelid386 andlower eyelid388 together over the top of theeye380. Incident light is received by theeye380 through thecornea382, where light is optically directed to light-sensing elements of the eye380 (e.g., rods and cones, etc.) to stimulate visual perception. The motion of theeyelids386,388 distributes a tear film across the exposedcorneal surface384 of theeye380. The tear film is an aqueous solution secreted by the lacrimal gland to protect and lubricate theeye380. When the eye-mountable device310 is mounted in theeye380, the tear film coats both the anterior andposterior sides324,326 with an inner layer390 (along the posterior side326) and an outer layer392 (along the anterior side324). The tear film layers390,392 can be about 10 micrometers in thickness and together account for about 10 microliters.
The tear film layers390,392 are distributed across thecorneal surface384 and/or theposterior side324 by motion of theeyelids386,388. For example, theeyelids386,388 raise and lower, respectively, to spread a small volume of tear film across thecorneal surface384 and/or theanterior side324 of the eye-mountable device310. Thetear film layer390 on thecorneal surface384 also facilitates mounting the eye-mountable device310 by capillary forces between theanterior side326 and thecorneal surface384. In some embodiments, the eye-mountable device310 can also be held over the eye in part by vacuum forces against thecorneal surface384 due to the concave curvature of the eye-facinganterior side326.
In some embodiments, a polymer layer defining theanterior side326 may be greater than 50 micrometers thick, whereas a polymer layer defining theposterior side324 may be less than 150 micrometers. Thus, when thesensor360 is mounted on an outward-facing surface335 (as shown inFIG. 3d) thesensor360 may be at least 50 micrometers away from theanterior side324 and may be a greater distance away from theposterior side326. However, in other examples, thesensor360 may be mounted on an inward-facingsurface333 of thestructure330 such that thesensor360 is facing theposterior side326. Thesensor360 could also be positioned closer to theanterior side324 than theposterior side326. With this arrangement, thesensor360 can receive analyte concentrations in thetear film392 via achannel373. In some examples, analyte concentrations in thetear film390 and/or392 may diffuse through thetransparent polymer320 to thesensor360. As a result, the eye-mountable device310 might not include thechannel373.
While the body-mountable device has been described as comprising the eye-mountable device110 and/or the eye-mountable device310, the body-mountable device could comprise other mountable devices that are mounted on or in other portions of the human body.
For example, in some embodiments, the body-mountable device may comprise a tooth-mountable device. In some embodiments, the tooth-mountable device may take the form of or be similar in form to the eye-mountable device110 and/or the eye-mountable device310. For instance, the tooth-mountable device could include a polymeric material or a transparent polymer that is the same or similar to any of the polymeric materials or transparent polymers described herein and a substrate or a structure that is the same or similar to any of the substrates or structures described herein. With such an arrangement, the tooth-mountable device may be configured to detect at least one analyte in a fluid (e.g., saliva) of a user wearing the tooth-mountable device.
Moreover, in some embodiments, the body-mountable device may comprise a skin-mountable device. In some embodiments, the skin-mountable device may take the form of or be similar in form to the eye-mountable device110 and/or the eye-mountable device310. For instance, the skin-mountable device could include a polymeric material or a transparent polymer that is the same or similar to any of the polymeric materials or transparent polymers described herein and a substrate or a structure that is the same or similar to any of the substrates or structures described herein. With such an arrangement, the skin-mountable device may be configured to detect at least one analyte in a fluid (e.g., perspiration, blood, etc.) of a user wearing the skin-mountable device.
Further, some embodiments may include privacy controls which may be automatically implemented or controlled by the wearer of a body-mountable device. For example, where a wearer's collected physiological parameter data and health state data are uploaded to a cloud computing network for trend analysis by a clinician, the data may be treated in one or more ways before it is stored or used, so that personally identifiable information is removed. For example, a user's identity may be treated so that no personally identifiable information can be determined for the user, or a user's geographic location may be generalized where location information is obtained (such as to a city, ZIP code, or state level), so that a particular location of a user cannot be determined.
Additionally or alternatively, wearers of a body-mountable device may be provided with an opportunity to control whether or how the device collects information about the wearer (e.g., information about a user's medical history, social actions or activities, profession, a user's preferences, or a user's current location), or to control how such information may be used. Thus, the wearer may have control over how information is collected about him or her and used by a clinician or physician or other user of the data. For example, a wearer may elect that data, such as health state and physiological parameters, collected from his or her device may only be used for generating an individual baseline and recommendations in response to collection and comparison of his or her own data and may not be used in generating a population baseline or for use in population correlation studies.
FIG. 4 is a top view of astructure430, according to an example embodiment. In particular, thestructure430 includes aspacer478 configured to maintain substantially uniform spacings between adjacent conductive loops in a plurality ofconductive loops472. The term “substantially uniform,” as used in this disclosure, refers to exactly uniform and/or one or more deviations from exactly uniform that do not significantly impact embedding an structure in a body-mountable device as described herein.
More specifically, thestructure430 has anouter diameter432 and aninner diameter434 and includeselectronics440,electronics450, a sensor460, and anantenna470 disposed thereon. Theouter diameter432 may take the form of or be similar in form to theouter diameter232 and/or theouter diameter332; theinner diameter434 may take the form of or be similar in form to theinner diameter234 and/or theinner diameter334; theelectronics440 may take the form of or be similar in form to thecontroller150, theelectronics240, and/or theelectronics340, theelectronics450 may take the form or be similar in form to thecontroller150, theelectronics250, and/or theelectronics350; and the sensor460 may take the form or be similar in form to thebio-analyte sensor162, thesensor260, and/or thesensor360.
Theantenna470 is configured for communications and/or harvesting energy, like theantenna270 and theantenna370 are configured for communications and/or harvesting energy. As noted, theantenna470 includes the plurality ofconductive loops472. The plurality ofconductive loops472 is spaced apart from each other between theouter diameter432 and theinner diameter434. In the illustrated example, the plurality ofconductive loops472 includes threeconductive loops472A,472B, and472C. However, in other examples, a plurality of conductive loops may include more than three conductive loops, such as five conductive loops, nine conductive loops, etc.
Theconductive loops472A,472B, and472C can have an arrangement similar to an arrangement of theconductive loops272A,272B, and272C and/or theconductive loops372A,372B, and372C. As shown inFIG. 4, theconductive loops472A,472B, and472C are connected in parallel. With this arrangement, each of the conductive loops in the plurality ofconductive loops472 is electrically connected to theelectronics440, theelectronics450, and the sensor460 via afirst connection474 and asecond connection476. And theelectronics440, theelectronics450, and the sensor460 are electrically connected via thefirst connection474 and thesecond connection476. Thefirst connection474 and thesecond connection476 may take the form of or be similar in form to theinterconnects151 and157, thefirst connection274 and thesecond connection276, and/or thefirst connection374 and thesecond connection376.
Moreover, as shown inFIG. 4, theconductive loops472A,472B, and472C are substantially concentric. And as shown inFIG. 4, theconductive loops472A,472B, and472C are spaced apart from each other between theouter diameter432 and theinner diameter434. In an example, theconductive loops472A,472B, and472C can be spaced apart from adjacent conductive loops by a distance between 100 to 200 micrometers. Other distances are possible as well.
Theconductive loops472A,472B, and472C may have a width that is the same or similar to a width of theconductive loops272A,272B, and272C and/or theconductive loops372A,372B, and372C. Moreover, each of the conductive loops in the plurality ofconductive loops472 can comprise a respective metal layer disposed between respective polymer layers, like the conductive loops in the plurality ofconductive loops272 comprise a respective metal layer disposed between respective polymer layers. And the plurality ofconductive loops472 can be formed like the plurality ofconductive loops272 and/or the plurality ofconductive loops372 is formed.
Thestructure430 may be embedded in a transparent polymer, such as thetransparent polymer320. For instance, when thestructure430 is embedded in the transparent polymer, when each of the conductive loops in the plurality ofconductive loops472 comprise a respective metal layer disposed between respective polymer layers, the metal and polymer layers in each conductive loop in the plurality ofconductive loops472 can be spaced apart from the metal and polymer layers in each adjacent conductive loop in the plurality ofconductive loops472. And the transparent polymer can extend between adjacent conductive loops in the plurality ofconductive loops472.
As noted, thestructure430 includes thespacer478. When thestructure430 is embedded in the transparent polymer theconductive loops472A,472B, and472C may not move relative to each other based on thespacer478.
As shown inFIG. 4, thespacer478 is connected to theconductive loops472A,472B, and472C and is located on thestructure430 substantially opposite of thesensor260. Other locations of thespacer478 on thestructure430 are possible as well. For instance, thespacer478 could be located on thestructure430 at a predetermined rotational orientation, such as 30 degrees, 45 degrees, 60 degrees, 90 degrees, etc. The term “substantially opposite,” as used in this disclosure, refers to exactly opposite (e.g., a rotational orientation of 180 degrees) or one or more deviations from exactly opposite that do not significantly impact embedding a structure in a body-mountable device as described herein.
Thespacer478 could take various different forms in various different embodiments. For example, in some embodiments, thespacer478 can have a width between 50 and 300 micrometers. Other widths of thespacer478 are possible as well. Moreover, in some embodiments, thespacer478 can comprise a metal, such as gold, platinum, palladium, titanium, aluminum, copper, and/or silver. In some examples, thespacer478 can comprise the same metal as the respective metal layers of theconductive loops472A,472B, and472C. However, in other examples, thespacer478 can comprise a different metal than the respective metal layers of theconductive loops472A,472B, and472C. In an example, thespacer478 can be formed by a process that includes electroplating.
Furthermore, in some embodiments, thespacer478 can comprise a polymeric material, such as PET or paralyene. In some examples, thespacer478 can comprise the same polymeric material as the respective polymer layers of theconductive loops472A,472B, and472C. However, in other examples, thespacer478 can comprise a different polymeric material than the respective polymer layers of theconductive loops472A,472B, and472C. In an example, thespacer478 can be formed by a process that includes chemical vapor deposition.
And in some embodiments, thespacer478 can comprise a metal layer disposed between polymer layers, like the respective metal layers disposed between the respective polymer layers of theconductive loops472A,472B, and472C.
In an example, thespacer478 is formed by a process that includes etching a portion of a metal and/or a polymeric material with an inductively coupled plasma, such as an oxygen plasma.
In the illustrated example, thestructure430 includes one spacer, thespacer478. However, in other examples, a structure may include more than one spacer, such as two spacers, three spacers, four spacers, etc. For instance, a structure could include one or more spacers configured to maintain substantially uniform spacings between adjacent conductive loops in a plurality of conductive loops. And each spacer in the one or more spacers could be located on the structure in a predetermined rotational orientation, such as 30 degrees, 45 degrees, 60 degrees, 90 degrees, etc. Each of the spacers in the one or more spacers could take the form or be similar in form to thespacer478.
FIG. 5 is a top view of astructure530, according to an example embodiment. In particular, thestructure530 includes anantenna570 that includes a plurality ofconductive loops572 that includes threeconductive loops572A,572B, and572C. As shown inFIG. 5, theconductive loops572A,572B, and572C are connected in series.
More specifically, thestructure530 has anouter diameter532, and aninner diameter534. Theouter diameter532 may take the form of or be similar in form to theouter diameter232, theouter diameter332, and/or theouter diameter432; and theinner diameter434 may take the form of or be similar in form to theinner diameter234, theinner diameter334, and or theinner diameter434.
As noted, thestructure530 includes theantenna570. Theantenna570 is configured for communications and/or harvesting energy, like theantenna270, theantenna370, and theantenna470 are configured for communications and/or harvesting energy. Theantenna570 includes the plurality ofconductive loops572 spaced apart from each other between theouter diameter532 and theinner diameter534. In the illustrated example, the plurality ofconductive loops572 includes theconductive loops572A,572B, and572C. However, in other examples, a plurality of conductive loops may include more than three conductive loops, such as five conductive loops, nine conductive loops, etc.
As noted, theconductive loops572A,572B, and572C are connected in series. With this arrangement, theconductive loop572A is electrically connected to anelectrical component555 via afirst connection574 and the conductive loop572C is electrically connected to theelectrical component555 via asecond connection576. Theelectrical component555 could include electronics (e.g., thecontroller150, theelectronics240, theelectronics250, theelectronics340, theelectronics350, theelectronics440, and/or the electronics450) and/or a sensor (e.g., theanalyte bio-sensor162, thesensor260, thesensor360, and/or the sensor460). When theelectrical component555 includes more than one component, the more than one component could be arranged in series.
As shown inFIG. 5, the conductive loop572C is connected to the second connection via abridge573. Thebridge573 may insulate the conductive loop572C from the conductive loop572B and/or theconductive loop572A. In some embodiments, thebridge573 can comprise a polymeric material, such as PET or paralyene. And in some examples, thebridge573 can comprise the same polymeric material as thespacer478 and/or the respective polymer layers of theconductive loops272A,272B, and272C, theconductive loops372A,372B, and372C, and/or theconductive loops472A,472B, and472C. However, in other examples, thebridge573 can comprise a different polymeric material than thespacer478 and/or the respective polymer layers. Thebridge573 may be other materials as well, such as silicon. Moreover, in some embodiments, thebridge573 may include an integrated circuit. And in at least one such embodiment, theconductive loop572A, the conductive loop572B, and the conductive loop572C may cross at thebridge573.
In the illustrated example, the plurality ofconductive loops572 is a continuous material arranged in multiple windings, shown as theconductive loops572A,572B, and572C. However, in other examples, a plurality of conductive loops may not be a continuous material.
As shown inFIG. 5, theconductive loops572A,572B, and572C are substantially concentric. And as shown inFIG. 5, theconductive loops572A,572B, and572C are spaced apart from each other between theouter diameter532 and theinner diameter534. In an example, theconductive loops572A,572B, and572C are spaced apart from adjacent conductive loops by a distance between 100 to 200 micrometers. Other distances are possible as well.
Theconductive loops572A,572B, and572C may have a width that is the same or similar to a width of theconductive loops272A,272B, and272C; theconductive loops372A,372B, and372C; and/or theconductive loops472A,472B, and472C. Moreover, each of the conductive loops in the plurality ofconductive loops572 can comprise a respective metal layer disposed between respective polymer layers, like the conductive loops in the plurality ofconductive loops272 comprise a respective metal layer disposed between respective polymer layers. In an example, theconductive loops572A,572B, and572C can be formed by a process that includes electroplating, chemical vapor deposition, and etching, using an inductively coupled plasma, such as oxygen plasma.
Thestructure530 may be embedded in a transparent polymer, like thestructure330 is embedded in thetransparent polymer320. When thestructure530 is embedded in the transparent polymer, theconductive loops572A,572B, and572C may move relative to each other. In an example, movement of theconductive loops572A,572B, and572C may be the same as movement of theconductive loops372A,372B, and372C. However, in other examples, movement of theconductive loops572A,572B, and572C may be greater (or less) than movement of theconductive loops372A,372B, and372C.
For instance, when thestructure530 is embedded in the transparent polymer and each of the conductive loops in the plurality ofconductive loops572 comprise a respective metal layer disposed between respective polymer layers, the metal and polymer layers in each conductive loop in the plurality ofconductive loops572 can be spaced apart from the metal and polymer layers in each adjacent conductive loop in the plurality ofconductive loops572. And the transparent polymer can extend between adjacent conductive loops in the plurality ofconductive loops572.
Moreover, the metal and polymer layers of conductive loop572B can be spaced apart from the metal and polymer layers of adjacentconductive loop572A by a first distance, and the conductive loop572B may be spaced apart from the adjacent conductive loop572C by a second distance. The first and second distances can be between 100 to 200 micrometers. Other distances are possible as well.
The first distance could be a different value than the second distance. For instance, the first distance can be greater (or less) than the second distance. And the first distance and/or the second distance could vary. As one example, the first distance can vary based on a rotational orientation of the conductive loop572B and/or the conductive loop572C relative to theconductive loop572A. Moreover, in some embodiments, the second distance can vary based on a rotational orientation of the conductive loop572C and/or theconductive loop572A relative to the conductive loop572B.

III. EXAMPLE METHODS

FIG. 6 is a flow chart illustrating a method, according to an example embodiment. More specifically, themethod600 involves forming a first polymer layer, as shown byblock602. Themethod600 may then involve positioning a structure on the first polymer layer, as shown byblock604. Further, themethod600 may then involve conforming the structure positioned on the first polymer layer to a curvature of the first polymer layer, as shown byblock606. Themethod600 may then involve forming a second polymer layer over the first polymer layer and the structure, as shown byblock608.

For purposes of illustration, themethod600 is described below as being carried out by a fabrication device that utilizes cast or compression molding. It should be understood, however, thatmethod600 may be carried out by a fabrication device that utilizes other methods for forming the polymer layers.

Moreover, for purposes of illustration, themethod600 is described below in a scenario where a body-mountable device comprises an eye-mountable device. It should be understood, however, that themethod600 may involve scenarios where the body-mountable device comprises other mountable devices that are mounted on or in other portions of the human body. For example, themethod600 may involve scenarios where the body-mountable device comprises a tooth-mountable device and/or a skin-mountable device as described herein.

A. Forming a First Polymer Layer

As mentioned above, atblock602, the fabrication device may be used to form a first polymer layer. The fabrication device may include molding pieces, such as molding pieces that are suitable for cast molding.FIG. 7aillustrates afabrication device700 that includes example molding pieces that may be used to form the first polymer layer. In particular,FIG. 7aillustrates afabrication device700 including afirst molding piece702 and asecond molding piece704. Thefirst molding piece702 and thesecond molding piece704 may define a first cavity. Thesecond molding piece704 may be filled with a polymer material706, and the polymer material706 may be compressed into afirst polymer layer708 by thefirst molding piece702.

After the polymer material706 is compressed into thefirst polymer layer708, thefabrication device700 may cure thefirst polymer layer708. Curing involves the hardening of a polymer material by cross-linking of polymer chains, and curing may be, for example, brought about by chemical additives, ultraviolet radiation, electron beam, and/or heat. In an example, the polymer material706 can be a light-curable polymer material, and thefabrication device700 may be configured to cure the light-curable polymer material using light, such as ultraviolet light or visible light.

In an example, thefirst polymer layer708 may be cured to a partially-cured state. In an example, this may involve curing the material to a partially-cured state that is approximately 50-75% of a fully cured state. Other partially-cured states are possible as well. Beneficially, by partially curing the first polymer layer to a partially-cured state, thefirst polymer layer708 may have a tackiness that facilitates adhesion thereto. With this arrangement, the tackiness may ensure that a structure conformed to a curvature of thefirst polymer layer708 remains securely fixed in a given location during subsequent formation steps.

The tackiness exhibited by the partially-curedfirst polymer layer708 may be different for different polymers. Accordingly, thefabrication device700 may be configured to cure different polymer materials differently than other polymer materials (e.g., a first polymer material may be cured more than a second polymer material). Further, in addition to light curing, other methods of curing are possible as well, such as chemical additives and/or heat. Yet still further, in other example embodiments, the first polymer layer may be completely cured. Alternatively, thefabrication device700 may bypass the curing process at this stage.

Thefirst molding piece702 and thesecond molding piece704 may be configured to achieve a given desired thickness of thefirst polymer layer708. For instance, in an example, thefirst polymer layer708 can have a thickness of less than 150 micrometers. In an example embodiment, thefirst molding piece702 and thesecond molding piece704 can be designed so as to allow for a layer having less than a 150 micrometer thickness between the two cavities. As such, when thefirst molding piece702 and thesecond molding piece704 are pressed together during the formation of thefirst polymer layer708, the resultingpolymer layer708 will have a thickness of less than 150 micrometers.

In an example, the thickness of thefirst polymer layer708 can be selected based on a particular analyte or analytes an eye-mountable device is configured to detect. For example, an optimal thickness for a first analyte may be 10 micrometers, while an optimal thickness for a second analyte may be 25 micrometers. Other examples are possible as well.

In an example, the polymer material706 can be any material that can form an eye-compatible polymer layer. For example, the polymer material706 may be a formulation containing polymerizable monomers, such as hydrogels, silicone hydrogels, silicone elastomers, and rigid gas permeable materials. Further, the polymer material706 may form a transparent or substantially transparent polymer layer. As such, the use of the polymer material706 may result in an eye-mountable device through which the wearer can see when mounted on the wearer's eye. In an example, the polymer material706 can be a hydrogel material, such as silicone hydrogel. As known in the art, hydrogel materials are commonly used in contact-lens technology and are well-suited for eye-mountable devices. Other materials are possible as well.

In an example, thefirst molding piece702 and/or thesecond molding piece704 can be configured so as to allow sufficient pinch off to provide for suitable edges for an eye-mountable device.

Thefirst polymer layer708 defines aposterior side710 of an eye-mountable device. That is, thefirst polymer layer708 defines an outer edge of the eye-mountable device. When mounted on an eye of a user, theposterior side710 of the eye-mountable device defined by thefirst polymer layer708 corresponds to a side of the device touching the eye of the user. Thefirst molding piece702 may be shaped so as to define a shape of theposterior side710. For example, a curvature of theposterior side710 may be defined by thefirst molding piece702. Thesecond molding piece704 may be shaped so as to define a shape of apositioning surface711 of the first polymer layer. For example, thesecond molding piece704 may define a curvature of apositioning surface711 of thefirst polymer layer708. In an example, a structure can be conformed to the curvature of thepositioning surface711 of thefirst polymer layer708.

Thefirst polymer layer708 can further comprise analignment feature712. In an example, thealignment feature712 can comprise an asymmetric peg. The asymmetric peg can be a variety of shapes. For instance, the asymmetric peg can have a star-shaped or cross-shaped cross section. Other shapes of the asymmetric peg are possible as well.

As mentioned above, althoughFIG. 7aillustrates forming thefirst polymer layer708 through cast molding, other methods for formingfirst polymer layer708 are possible as well. For example, thefirst polymer layer708 may be formed via injection molding. In injection molding, rather than polymer material being compressed between molding pieces, molding material may be heated and injected or otherwise forced into a molding piece or pieces. The injected molding material may then cool and harden to the configuration of the molding piece or pieces.

As another example, thefirst polymer layer708 may be formed via spin casting. Through spin-casting techniques, the fabrication device may form a first polymer layer of a precise thickness. In an example, a spin-casting mold may be spun along its central access at a set speed, and the polymer may be introduced to the mold as the mold is spinning in order to form a first polymer layer. The final thickness of the first polymer layer may be influenced by various factors, including but not limited to the spin-casting mold, the amount of polymer introduced to the spin-casting mold, properties of the polymer such as viscosity, and/or the speed at which the spin-casting mold is rotated. These factors may be varied in order to result in a first polymer layer of a well-defined thickness.

B. Positioning a Structure on the First Polymer Layer

As mentioned above, atblock604, a structure may be positioned on the first polymer layer.FIGS. 7band7cillustrate an example in which astructure730 is positioned on thefirst polymer layer708.

Thestructure730 has anouter diameter732 and aninner diameter734 and includeselectronics740,electronics750, asensor760, and anantenna770 disposed thereon. Thestructure730 may take the form of or be similar in form to thesubstrate130, thestructure230, thestructure330, thestructure430 and/or thestructure530. In some embodiments, thestructure730 can further include one or more spacers, such as thespacer478.

Theouter diameter732 may take the form of or be similar in form to theouter diameter232, theouter diameter332, theouter diameter432, and/or theouter diameter532; theinner diameter734 may take the form of or be similar in form to theinner diameter234, theinner diameter334, and or theinner diameter434 and/or theouter diameter534; theelectronics740 may take the form or be similar in form to thecontroller150, theelectronics240, theelectronics340, theelectronics440 and/or theelectronics555; theelectronics750 may take the form of or be similar in form to thecontroller150, theelectronics250, theelectronics350, theelectronics450, and/or theelectronics555; and thesensor760 may take the form of or be similar in form to thebio-analyte sensor162, thesensor260, thesensor360, the sensor460.

As noted, thestructure730 includes theantenna770. Theantenna770 is configured for communications and/or harvesting energy, like theantenna270, theantenna370, theantenna470, and theantenna570 are configured for communications and/or harvesting energy. Theantenna770 includes a plurality of conductive loops spaced772 apart from each other between theouter diameter732 and theinner diameter734. In the illustrated example, the plurality ofconductive loops772 includes three

conductive loops

772A,772B, and772C. However, in other examples, a plurality of conductive loops may include more than three conductive loops, such as five conductive loops, nine conductive loops, etc.

As shown inFIG. 7b, the

conductive loops

772A,772B, and772C are substantially concentric. And as shown inFIG. 7b, the

conductive loops

772A,772B, and772C are spaced apart from each other between theouter diameter732 and theinner diameter734. In an example, the

conductive loops

772A,772B, and772C are spaced apart from adjacent conductive loops by a distance between 100 to 200 micrometers. Other distances are possible as well. In the illustrated example, the

conductive loops

772A,772B, and772C are connected in parallel. However, in other examples, conductive loops can be connected in series, like theconductive loops572A,572B, and572C are connected in series.

In order to position thestructure730, thefabrication device700 may separate thefirst molding piece702 from thesecond molding piece704. When thefabrication device700 separates thefirst molding piece702 from thesecond molding piece704, thefirst polymer layer708 may stick to a side of thefirst molding piece702. In an example, thefirst polymer layer708 and/or thefirst molding piece702 can be surface treated, such that thefirst polymer layer708 sticks to the side of thefirst molding piece702. Additionally or alternatively, thesecond molding piece704 can be surface treated, such that thefirst polymer layer708 sticks to the side of thefirst molding piece702.

In an example, positioning thestructure730 on thefirst polymer layer708 can include aligning thestructure730 with thealignment feature712. In one example, theinner diameter734 can be asymmetric and thealignment feature712 includes an asymmetric peg such that theinner diameter734 receives thealignment feature712 in only a predetermined rotational orientation (relative alignment between thealignment feature712 and theinner diameter734 inFIG. 7cis not necessarily to scale). However, other ways of providing a predetermined rotational orientation of thestructure730 by alignment with thealignment feature712 are also possible.

Alternatively, thefabrication device700 can include a positioning apparatus (not shown), such as a robotic system, configured to position thestructure730 on thefirst polymer layer708. For instance, the positioning apparatus may (i) pick up the structure730 (e.g., via suction), (ii) position thestructure730 above thefirst polymer layer708, and then (iii) lower thestructure730 toward thefirst polymer layer708. With this arrangement, the positioning apparatus may position thestructure730 in a predetermined rotational orientation. When thestructure730 is positioned in a predetermined orientation, the positioning apparatus may then release the structure730 (e.g., by releasing the suction). With this approach, thefirst polymer layer708 might not include thealignment feature712.

The positioning apparatus may further include a vision system configured to assist with positioning thestructure730 on thefirst polymer layer708. Such a vision system may facilitate guiding thestructure730 to a precise location on thefirst polymer layer708. In an example, the vision system can be appropriate for situations in which one or more production specifications for an eye-mountable device, such as the eye-mountable device310, have requirements with very low tolerances related to the positioning of a sensor, such as thesensor360, within the eye-mountable device310.

In some situations, such as for large-scale production purposes, it may be desirable to not only place thestructure730 in a predetermined orientation, but it may also be desirable to repeatedly place and maintain thestructure730 at this precise location for a plurality of eye-mountable devices. Beneficially, fabrication of an eye-mountable device in accordance with an example embodiment allows for such repeatable and precise positioning.

FIG. 7cillustrates thestructure730 positioned on thefirst polymer layer708. With this arrangement, thesensor760 may be mounted at a particular angle along a circumference of thefirst polymer layer708. As a result, thesensor760 may be placed at a precise location in an XYZ plane on thefirst polymer layer708. As one example, thesensor760 may rest at a 6 o'clock position of thefirst polymer layer708. As another example, thesensor760 may rest at a 12 o'clock position of thefirst polymer layer708.

C. Conforming the Structure Positioned on the First Polymer Layer to a Curvature of the First Polymer Layer

As mentioned above, atblock606, the structure positioned on the first polymer layer may be conformed to a curvature of the first polymer layer.FIG. 7dillustrates an example in which thestructure730 is conformed to the curvature of thepositioning surface711 of thefirst polymer layer708.

In an example, conforming thestructure730 to the curvature of thepositioning surface711 of the first polymer layer can include bending thestructure730. In one example, the positioning apparatus may bend thestructure730, such that thestructure730 conforms to the curvature of thepositioning surface711 of thefirst polymer layer708. The positioning apparatus may bend thestructure730 by applying a force and/or a torque to one or more portions of thestructure730. However, other ways of conforming thestructure730 to the curvature of thepositioning surface711 are possible as well.

Moreover, in an example, during conforming the

conductive loops

772A,772B, and772C may move relative to each other. Beneficially, such movement can reduce buckling of thestructure730 when it is conformed to a curvature of the first polymer layer, such as the curvature of thepositioning surface711 of thefirst polymer layer708. An amount and/or type of movement of the

conductive loops

772A,772B, and772C may be based on a variety of parameters, such as a material, a width, a thickness, and/or a connection (e.g., parallel or series) of the

conductive loops

772A,772B, and772C and/or a material, a thickness, and a curvature of thefirst polymer layer708. Other parameters are possible as well. And in embodiments where thestructure730 further includes one or more spacers, such as thespacer478, the

conductive loops

772A,772B, and772C may not move relative to each other based on the one or more spacers.

During fabrication of an eye-mountable device, such as the eye-mountable device310, it may be desirable for thestructure730 to remain in a fixed position during fabrication of the eye-mountable device. For instance, movement of thestructure730 during subsequent formation steps, such as formation of a second polymer layer, may result in improper placement of thestructure730 relative to the surrounding polymer layers. As one example, movement of thestructure730 during filling a mold piece with a polymeric material to form the second polymer layer and/or curing the second polymer layer can result in improper placement of thestructure730 relative to the surrounding polymer layers.

As noted above, in an example, thefirst polymer layer708 in a partially-cured state may have a tackiness that facilitates adhesion thereto. With this arrangement, thestructure730 may remain adhered to thefirst polymer layer708 in a secure location during subsequent formation steps.

D. Forming a Second Polymer Layer Over the First Polymer Layer and the Structure

As mentioned above, atblock608, the fabrication device may form a second polymer layer over the first polymer layer and the structure, such that the structure is fully enclosed by the first polymer layer and the second polymer layer.FIG. 7eillustrates thefabrication device700 including example molding pieces that may be used to form the second polymer layer. In particular,FIG. 7eillustrates athird molding piece722. Thefirst molding piece702 and thethird molding piece722 may define a second cavity.

Thefirst molding piece702, which already holds thefirst polymer layer708 to which thestructure730 is mounted (as illustrated inFIG. 7d), may be filled with a polymer material724. The polymer material724 may be formed into a second polymer layer726 by compression between thefirst molding piece702 and thethird molding piece722. As a result, the second polymer layer726 may mold over thestructure730, such that thestructure730 is fully enclosed by thefirst polymer layer708 and the second polymer layer726. In some embodiments, the second polymer layer can extend between adjacent conductive loops, such as theconductive loop772A and the conductive loop772B and/or the conductive loop772B and theconductive loop772C, in the plurality ofconductive loops772. With this arrangement, the second polymer layer726 may bond to thefirst polymer layer708 between the adjacent conductive loops in the plurality ofconductive loops772.

After the second polymer layer726 is formed, thefabrication device700 may cure the second polymer layer726. In an example, the second polymer layer726 can be cured like thefirst polymer layer708. However, in other examples, the second polymer layer726 may be cured by different techniques than thefirst polymer layer708. The second polymer layer726 can be cured by any of the techniques mentioned herein. In an example, thefabrication device700 may cure thefirst polymer layer708 at this stage.

After the second polymer layer726 is cured, there may not be a visible boundary line separating thefirst polymer layer708 from the second polymer layer726. As noted,FIG. 3aillustrates the eye-mountable device310. In particular,FIG. 3aillustrates the eye-mountable device300 includes thetransparent polymer320. Thetransparent polymer320 can be arranged like thefirst polymer layer708 and the second polymer layer726.

Returning toFIG. 7e, thefabrication device700 may further comprise one or more alignment pins (not shown), such as a plurality of dowel pins, for aligning thethird molding piece722 and thefirst molding piece702. The one or more alignment pins can assist in forming the second polymer layer726 by aligning thethird molding piece722 with thefirst molding piece702.

Thefirst molding piece702 and thethird molding piece722 may be configured to achieve a given desired thickness of a layer formed between the two pieces. As one example, thefirst molding piece702 and thethird molding piece722 may be designed so as to define a thickness of the second polymer layer726. As another example, thefirst molding piece702 and thethird molding piece722 may be designed so as to define a final thickness of an eye-mountable device, such as the eye-mountable device310. In an example, thefirst molding piece702 and thethird molding piece722 can be designed so as to allow for a layer having a given desired thickness between the two pieces (in addition to a thickness of the first polymer708). As such, when thefirst molding piece702 and thethird molding piece722 are pressed together during formation of a layer, the resulting layer will have the given desired thickness.

In an example, the second polymer layer726 has a thickness of greater than 50 micrometers. However, in other examples, the second polymer layer726 can have a thickness between 50 and 300 micrometers, such as 130 micrometers. It should be understood that since the second polymer layer726 molds over thestructure730, the second polymer layer726 may not have a uniform thickness. For instance, the thickness of the second polymer layer726 above thesensor760 may be less than the thickness of the second polymer layer726 that is not touching thesensor760.

In an example, the thickness of the second polymer layer726 can be selected based on a particular analyte or analytes that the eye-mountable device, such as the eye-mountable device310, is configured to detect. For example, an optimal thickness for a first analyte may be 10 micrometers, while an optimal thickness for a second analyte may be 25 micrometers. Other examples are possible as well.

In an example, the second polymer layer726 can be composed of the same polymer material as thefirst polymer layer708. However, in other examples, the second polymer layer726 can be composed of a different polymer material than thefirst polymer layer708. The second polymer layer726 can be any one of the polymer materials mentioned herein. In an example, thestructure730 can be more rigid than the second polymer layer726.

The second polymer layer726 defines an anterior side728 of an eye-mountable device. That is, the second polymer layer726 defines an outer edge of the eye-mountable device. When mounted on an eye of a user, the anterior side728 of the eye-mountable device defined by the second polymer layer726 corresponds to the side of the device that is not touching the eye of the user. Thethird molding piece722 may be shaped so as to define a shape of the anterior side728. For example, a curvature of the anterior side728 may be defined by thethird molding piece722.

E. Forming the First Polymer Layer and the Second Polymer Layer at the Same Time

The example methods described above involve a method of fabricating an eye-mountable device that involves first forming a first polymer layer and subsequently forming a second polymer layer. In another example, the first polymer layer defining a posterior side of the eye-mountable device and the second polymer layer defining an anterior side of the eye-mountable device may be substantially formed around a structure, such as thestructure730, at the same time. The term “substantially formed,” as used in this disclosure, refers to exactly formed and/or one or more deviations from exactly formed that do not significantly impact embedding a structure in a body-mountable device as described herein. Further, in such an example, positioning the structure on the first layer and conforming the structure positioned on the first layer to a curvature of the first layer would take place at the same time as the formation of the first polymer layer and the second polymer layer.

For instance, in accordance with an example embodiment, the fabrication device may be configured to position a structure within a molding cavity or cavities, and the fabrication device may then form the first polymer layer and the second polymer layer around the structure. In such an example, the fabrication device may be configured to inject mold into the molding cavity, and the injected mold may encapsulate the structure. In this example, the fabrication device may include a molding cavity or cavities that have at least one opening configured to allow the fabrication device to hold the structure in place as the first and second polymer layers are formed around the structure. The molding cavity or cavities may be filled with the polymer material, and this introduction of the polymer material may form the polymer layers around the structure.

F. Forming a Channel Through the Second Polymer Layer

In some embodiments, the example methods described above may further include forming a channel through a second polymer layer, such that a sensor (e.g., sensor760), is configured to receive one or more analytes via the channel. In such an example, the channel may be formed by removing material from the second polymer layer. The material from the second polymer layer can be removed to form the channel in a variety of ways. For instance, the material from the second polymer layer can be removed to form the channel via a process that includes drilling, ablation, etching, etc.

In another example, a mask layer may be formed before forming the second polymer layer. Further, in such an example, after the second polymer layer is formed, the mask layer may be removed to form a channel. The mask layer can be removed to form the channel in a variety of ways. For instance, the mask layer can be removed to form the channel via a process that includes etching the mask layer and/or dissolving the mask layer in a fluid.

IV. CONCLUSION

It should be understood that arrangements described herein are for purposes of example only. As such, those skilled in the art will appreciate that other arrangements and other elements (e.g., machines, interfaces, functions, orders, and groupings of functions, etc.) can be used instead, and some elements may be omitted altogether according to the desired results. Further, many of the elements that are described are functional entities that may be implemented as discrete or distributed components or in conjunction with other components, in any suitable combination and location.

While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims, along with the full scope of equivalents to which such claims are entitled. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting.

Where example embodiments involve information related to a person or a device of a person, some embodiments may include privacy controls. Such privacy controls may include, at least, anonymization of device identifiers, transparency and user controls, including functionality that would enable users to modify or delete information relating to the user's use of a product.

Further, in situations in where embodiments discussed herein collect personal information about users, or may make use of personal information, the users may be provided with an opportunity to control whether programs or features collect user information (e.g., information about a user's medical history, social network, social actions or activities, profession, a user's preferences, or a user's current location), or to control whether and/or how to receive content from the content server that may be more relevant to the user. In addition, certain data may be treated in one or more ways before it is stored or used, so that personally identifiable information is removed. For example, a user's identity may be treated so that no personally identifiable information can be determined for the user, or a user's geographic location may be generalized where location information is obtained (such as to a city, ZIP code, or state level), so that a particular location of a user cannot be determined. Thus, the user may have control over how information is collected about the user and used by a content server.

Claims

1. A body-mountable device comprising:

a transparent polymer, wherein the transparent polymer defines a posterior side and an anterior side of the body-mountable device; and

a structure embedded in the transparent polymer, wherein the structure has an outer diameter and an inner diameter and includes a sensor configured to detect an analyte and an antenna, wherein the antenna includes a plurality of conductive loops spaced apart from each other between the outer diameter and the inner diameter.

2. The body-mountable device ofclaim 1, wherein the body-mountable device comprises an eye-mountable device.

3. The body-mountable device ofclaim 1, wherein the body-mountable device comprises a tooth-mountable device.

4. The body-mountable device ofclaim 1, wherein the body-mountable device comprises a skin-mountable device.

5. The body-mountable device ofclaim 1, wherein the conductive loops are substantially concentric.

6. The body-mountable device ofclaim 1, wherein the plurality of conductive loops comprises at least three conductive loops.

7. The body-mountable device ofclaim 1, wherein the conductive loops are connected in parallel.

8. The body-mountable device ofclaim 1, wherein the conductive loops are connected in series.

9. The body-mountable device ofclaim 1, wherein each conductive loop in the plurality of conductive loops comprises a respective metal layer disposed between respective polymer layers.

10. The body-mountable device ofclaim 9, wherein the metal and polymer layers in each conductive loop are spaced apart from the metal and polymer layers in each adjacent conductive loop in the plurality of conductive loops.

11. The body-mountable device ofclaim 10, wherein the metal and polymer layers of a particular conductive loop in the plurality of conductive loops are spaced apart from the metal and polymer layers of a first adjacent conductive loop in the plurality of conductive loops by a first distance, and wherein the metal and polymer layers of the particular conductive loop are spaced apart from the metal and polymer layers of a second adjacent conductive loop in the plurality of conductive loops by a second distance.

12. The body-mountable device ofclaim 11, wherein the first distance varies based on a rotational orientation of the particular conductive loop relative to the first adjacent conductive loop.

13. The body-mountable device ofclaim 11, wherein the second distance varies based on a rotational orientation of the particular conductive loop relative to the second adjacent conductive loop.

14. The body-mountable device ofclaim 10, wherein the transparent polymer extends between adjacent conductive loops in the plurality of conductive loops.

15. The body-mountable device ofclaim 10, wherein the polymer layers in each conductive loop comprise paralyene.

16. The body-mountable device ofclaim 1, further comprising one or more spacers configured to maintain substantially uniform spacings between adjacent conductive loops in the plurality of conductive loops.

17. The body-mountable device ofclaim 16, wherein the one or more spacers comprise a polymeric material.

18. The body-mountable device ofclaim 16, wherein the one or more spacers comprise a metal.

19. The body-mountable device ofclaim 16, wherein the one or more spacers comprise one spacer positioned on the structure substantially opposite of the sensor.

20. The body-mountable device ofclaim 16, wherein the one or more spacers are positioned on the structure at a predetermined rotational orientation.

21. A method comprising:

forming a first polymer layer, such that the first polymer layer has a curvature, wherein the first polymer layer defines a posterior side of a body-mountable device;

positioning a structure on the first polymer layer, wherein the structure has an outer diameter and an inner diameter and includes a sensor configured to detect an analyte and an antenna, and wherein the antenna includes a plurality of conductive loops spaced apart from each other between the outer diameter and the inner diameter;

conforming the structure positioned on the first polymer layer to the curvature of the first polymer layer; and

forming a second polymer layer over the first polymer layer and the structure, such that the structure is fully enclosed by the first polymer layer and the second polymer layer, wherein the second polymer layer defines an anterior side of the body-mountable device.

22. The method ofclaim 21, wherein the body-mountable device comprises an eye-mountable device.

23. The method ofclaim 21, wherein the body-mountable device comprises a tooth-mountable device.

24. The method ofclaim 21, wherein the body-mountable device comprises a skin-mountable device.

25. The method ofclaim 21, wherein the plurality of conductive loops comprises at least three conductive loops.

26. The method ofclaim 21, the second polymer layer extends between adjacent conductive loops in the plurality of conductive loops.