US20020072111A1 - Drawn microchannel array devices and method of analysis using same - Google Patents

Abstract

Micro channel array devices drawn from a bulk preform having an array of components to reduce the cross section. The reduced cross section fiber like structure is cut to produce individual arrays of small scale. End caps are drawn and optionally micro machined. The end caps are used to provide input and output ports and other structures for use with the micro channel arrays. A micro channel array may be used with different end caps for analysis and may form a lab on a chip or a component thereof.

Description

BACKGROUND OF THE INVENTION
• 1. Field of the Invention[0001]
• The present invention relates generally to micro channel array structures. More particularly, the present invention relates to a device constructed by drawing a bulk preform to produce the micro channel array and a method of analysis utilizing such structures.[0002]
• 2. Background of the Invention[0003]
• As the demand for rapid, accurate and inexpensive analytical techniques has grown, there has been a drive to develop smaller analytical devices. Such small devices can provide the ability to run hundreds or thousands of simultaneous experiments in a single laboratory, allowing heretofore impossible or impractical results to be achieved. For example, combinatorial chemists may now perform thousands of simultaneous syntheses using a fraction of the time and materials necessary to perform even one conventional synthesis. Pharmaceutical researchers, DNA analysts and a wide variety of other biologists and chemists have benefited from the revolution in lab on a chip technologies.[0004]
• In order to make this possible, lab on a chip devices generally consist of microfluidic systems fabricated on a planar substrate. The substrate is generally selected according to the desired use and may be chosen to be resistant to acids, bases, salts, temperature extremes, temperature variations and/or applied electromagnetic fields. Further, the substrate should be relatively non-reactive with whatever chemicals might be used as part of the experiments to be performed. Examples of such substrates include glass, fused silica, quartz crystals, silicon, diamond and a variety of polymers. The substrate may be opaque or transparent, according to the application. For example, if optical detection is used to monitor the process, transparent substrates may be desirable to allow signal transmission.[0005]
• In many cases, the lab on a chip may essentially consist of several channels in a surface or in the interior of the substrate. A typical channel may have a depth of about 10 μm and a width of about 60 μm.[0006]
• Conventionally, lab on a chip devices have been manufactured using techniques similar to those used to fabricate microprocessors and other small scale electronic devices. For example it is common to use photolithography, chemical etching, plasma deposition, ion beam deposition, sputtering, chemical vapor deposition and other techniques commonly used in the semiconductor industry. Such techniques tend to be expensive and capital intensive. A single photolithography system can cost up to $20 million, not including the associated facilities such as clean rooms, vibration isolation structures and the like.[0007]
• Moreover, photolithography has been unable to successfully produce channels with high aspect ratios or straight walls, has an inherently low production rate and generally uses materials which are of lower quality such as borosilicate glass or plastics.[0008]
• In lieu of the above fabrication methods, micromachining techniques such as laser drilling, micro milling and the like or injection molding, microcasting or other casting techniques may be used. These techniques are generally slow and involve extremely high precision machining operations at the limit of current technologies.[0009]
• In the manufacture of optical fibers, a pure silica tube has a doped silica layer deposited onto its interior surface by a process known as chemical vapor deposition. The tube is heated to cause it to collapse into a solid rod. The rod is heated and drawn to greatly increase its length and reduce its cross section, creating a flexible optical fiber.[0010]
• For certain applications, a glass rod may be formed with pores therein prior to drawing to serve as a pipette, for example. The drawn fiber has tubes formed by the stretched pores. The tubes extend along the length of the fiber.[0011]
SUMMARY OF THE INVENTION
• The present invention addresses the needs identified above by providing a micro channel array device produced by forming a preform body having channels therein, drawing the preform body to reduce a cross section thereof and to increase a length of the preform body to form an extended array, and cutting the extended array to a desired length.[0012]
• Another embodiment of the present invention includes a method of analyzing by introducing a plurality of sample components to a drawn substrate having a length, the drawn substrate having at least two drawn channels formed therein. The drawn channels extend in a direction parallel to the length, the substrate includes inlets and outlets disposed in cooperating relation with the drawn channels[0013]
• Yet another embodiment of the present invention includes a device for analyzing a plurality of sample components, including a drawn substrate having a length, the drawn substrate having at least two drawn channels formed therein. The drawn channels extend in a direction parallel to the length. The device includes at least one endcap substrate having at least one endcap channel, the at least one endcap channel being in fluid communication with a selected one of the drawn channels, a plurality of the drawn channels, and/or another endcap channel.[0014]
• The device may be employed in a lab on a chip device.[0015]
• Another aspect of the present invention includes a drawn substrate manufactured by a process including providing a preform body having at least one channel and at least one optical waveguide preform therein and extending along a length of the preform body, drawing the preform body to extend the length thereof such that a length of the at least one channel is extended while substantially maintaining a cross sectional geometry of the at least one channel and such that a length of the at least one optical waveguide preform is extended while substantially maintaining a cross sectional geometry of the at least one optical waveguide preform, and cutting the drawn preform body to a desired length.[0016]
BRIEF DESCRIPTION OF THE DRAWINGS
• The accompanying drawings, which are incorporated in and constitute a part of this specification illustrate embodiments of the invention and together with the description, explain the objects, advantages, and principles of the invention.[0017]
• FIG. 1 shows an example of a drawn substrate according to the present invention.[0018]
• FIG. 2 shows an example of another drawn substrate according to the present invention.[0019]
• FIG. 3[0020]ashows an example of a drawn substrate incorporating a variety of drawn channel shapes according to the present invention.
• FIG. 3[0021]bshows an example of a micro channel array having tapered channels according to the present invention.
• FIGS. 4[0022]a-jshow examples of several drawn channel cross sections according to the present invention.
• FIGS. 5[0023]a-eshow examples of various endcap substrates and endcap channels configurations according to the present invention.
• FIGS. 6[0024]aand6bshow examples of drawn micro channel array devices according to the present invention.
• FIG. 7 shows an example of drawn micro channel array devices according to the present invention.[0025]
• FIG. 8 shows a partial side view of a drawn micro channel array device and end cap of FIG. 7.[0026]
• FIG. 9 shows an alternate partial side view of a drawn micro channel array device of FIG. 7.[0027]
• FIG. 10 shows an example of a multi-part drawn micro channel array devices in a lab on a chip structure according to the present invention.[0028]
• FIG. 11 shows another partial side view of a drawn micro channel array device having an integrated optical fiber according to the present invention.[0029]
• FIG. 12 shows an example of another drawn micro channel array devices having an integrated optical fiber according to the present invention.[0030]
• FIG. 13[0031]a-cshows examples of the means by which the light can be redirected from the axis of the fiber into or out of the micro channel array device.
• FIG. 14 shows an example of a drawn micro channel array structure having integrated drawn optical waveguides according to the present invention.[0032]
• FIG. 15[0033]a-bshows a side view examples of a drawn micro channel array device having integrated optical fibers, according to the present invention.
• FIG. 16 shows an example of a drawn microchanel array forming a diagnostic device according to the present invention.[0034]
• FIG. 17 shows an example of a capillary electrochromatography device according to the present invention.[0035]
• FIG. 18 is a schematic diagram of a micro capillary array device according to the present invention.[0036]
• FIGS. 19[0037]aand19bare schematic cross sections of drawn array devices according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
• In the following description, for purposes of explanation and not limitation, specific details are set forth such as particular components, techniques, etc. in order to provide a thorough understanding of the present invention. However, the invention may be practiced in other embodiments that depart from these specific details. In some instances, detailed descriptions of well-known devices may be omitted so as not to obscure the description of the present invention with unnecessary details.[0038]
• The following definitions are used herein:[0039]
• Drawn micro channel array devices: a complete structure consisting of any of drawn channels, endcaps, optical waveguides, optical fibers, lenses, reflectors, and portals.[0040]
• Draw process: the process whereby a substrate in the form of a block or rod is drawn, usually while being heated, stretching it along its length and reducing the cross sectional area to a desired size.[0041]
• Preform body: the initial substrate with machined or otherwise formed channels prior to having its cross sectional area reduced by the draw process. The preform body may have an optical waveguide embedded therein.[0042]
• Channels: the channels in the substrate prior to drawing.[0043]
• Drawn substrate: the body of material drawn from the preform body.[0044]
• Drawn channels: the channels within the drawn substrate.[0045]
• Endcap substrate: the body of material which is attached to either drawn substrates or other endcaps to enhance the function of the drawn micro channel array devices. The endcap substrates contain portals, mixing chambers, fluid conduits, and other structures used in the analysis technique.[0046]
• Endcap channels: the channels within the endcap substrate.[0047]
• Ports, outlets and portals: additional openings other than the channels machined or otherwise formed in either a channel substrate or endcap substrate. These ports put the drawn channels and endcap channels in fluid communication with interfaces outside the drawn substrate and endcap substrate. The ports generally connect to the channels at an angle between 1 and 90 degrees from the channel itself.[0048]
• Fluid communication: condition where conduits are sufficiently connected to allow fluid to flow there through.[0049]
• Conduit: any of drawn channel, endcap channel, or portal.[0050]
• Cross sectional geometry: a shape of a preform body, drawn substrate, or endcap substrate if viewed axially down its length. Includes similar geometric figures, that is figures with the same shape but of a differing scale.[0051]
• Optical waveguide preform: an initial optical waveguide in its bulk form prior to having its cross sectional area reduced by the draw process. This would be embedded in the above preform body, and drawn simultaneously with the channels.[0052]
• Drawn optical waveguide: the optical waveguide after undergoing the draw process.[0053]
• Reflector: a shape on an exterior surface of the drawn substrate or endcap substrate or on an interior surface of a channel that is designed such that light will reflect back into the substrate or channel within the substrate. The reflector would typically be coated with a reflective coating, including but not limited to silver.[0054]
• Exterior wall: the exterior surface of either a drawn substrate or endcap substrate.[0055]
• Interior wall: the interior surface of either a drawn substrate or endcap substrate which forms the defining edge of the drawn channel or endcap channel respectively.[0056]
• Channel spacing: the distance between channels in either the drawn substrate or endcap substrate.[0057]
• Rotational alignment: the alignment of channels in respect to other channels when rotated on the axis of the length. This can apply to either drawn channels or endcap channels.[0058]
• Angular alignment: the alignment of channels in respect to other channels when rotated radially to the length. This can apply to either drawn channels or endcap channels.[0059]
• Alignment Groove: A groove or protrusion from the surface of the drawn substrate or endcap substrate which allows for mechanical alignment of electrodes, optical fibers, lenses, detectors, transmitters, wires or other micro electromechanical devices to the drawn channels.[0060]
• Optical Isolator: A region of material which filters out desired wavelengths of light such that selected drawn channels or other regions of the drawn substrate or drawn endcaps are optically isolated from other channels, regions, or external areas.[0061]
• Optical Fiber: A separately drawn optical fiber which is inserted into or attached to the drawn micro channel array devices.[0062]
• Detection: The quantification of the amount of analyte in a drawn channel or endcap channel at a particular location within one of those channels.[0063]
• Referring now to FIG. 1, a drawn[0064]substrate10 according to the present invention is shown. A series of drawnchannels12 is arrayed across aface14 of the drawnsubstrate10. In this example, the drawnsubstrate10 is about 10 cm in length (L), about 1000 μm in height (H), and about 1500 μm in width (W). Each individual drawnchannel12 is about 50 μm in width and about 150 μm in height.
• In general, it is preferable to create arrays of channels having a cross sectional area in the range of 0.0001 mm[0065]²to 1 mm², preferably 0.0025 mm²to 0.25 mm², and most preferably 0.005 mm²to 0.025 mm².
• To form this array, a preform body is made, having similar proportions but of a larger size. The preform body contains channels which correspond to the drawn channels. The preform body is heated in a furnace and drawn, stretching it along its length and reducing the cross sectional area to the desired size while maintaining its geometry, that is the final, drawn substrate cross section is geometrically similar to the cross section of the original preform body, differing essentially only in size. By controlling the speed of the draw, the resulting cross sectional area can be controlled allowing formation of structures such as tapers. Preferably, a thickness monitor is provided. The thickness monitor supplies a control signal to the drawing process, so that a constant or appropriately varying cross section can be produced.[0066]
• Though the drawn array does not require any coating, a protective coating can be applied over the drawn array as is done for optical fibers. Various coatings may be applied, according to the intended use. Materials for a coating may be selected, for example, from polyimide, acrylate, fluorinated acrylate, silicone, metal or optical cladding. It may be desirable to make use of multiple coatings or multiple layers of a single coating. If necessary, the coating can then be cured in a curing oven. If the coating is selected to have a lower index of refraction than the drawn substrate, the drawn substrate can act as a light guide. In the case that the drawn array is flexible, it may be coiled onto a take-up drum.[0067]
• The preform body from which the drawn substrate is to be formed may be made from a variety of materials including, for example, glass, thermoplastic polymers, and ceramics. In many cases, the preferred materials will be fused silica or quartz. These materials provide high strength, good transmission of light, including UV wavelengths, high degree of homogeneity and low fluorescence. Additionally, since such materials are commonly used for manufacture of drawn optical components, their behavior when heated and drawn is reasonably well understood.[0068]
• An alternate drawn[0069]substrate10′ is shown in FIG. 2. The drawnsubstrate10′ of FIG. 2 has an annular array of drawnchannels12′ of similar dimensions to the drawnchannels12 of FIG. 1. Additionally a central throughhole16 is provided. The central throughhole16 may be used to accommodate mechanical connectors, to allow a light signal to be injected into the hole, to allow a light signal to be transmitted from the hole, or to allow passage of a material from one end of the drawn substrate to the other.
• In FIG. 3[0070]a, a drawnsubstrate20 is shown, illustrating several possible drawn channel shapes. Around channel22, arectangular channel24, atriangular channel26 and anoval channel28 are shown. FIG. 3bshows an example of a drawnsubstrate20′ having drawnchannels30 with taperedportions32. The tapered portions can be formed by varying various draw parameters including the rate of drawing, the draw tension, the draw temperature and the draw pressure during production of the drawn substrate. It may be necessary to machine the drawn substrate after the draw process in order to produce a desired exterior cross section while providing varying drawn channel cross sections. FIGS. 4a-j, likewise illustrate exemplary drawn channel and drawn substrate cross sections. A given drawn substrate may employ identical cross sectioned drawn channels as shown in FIG. 1, or, as shown in FIG. 3, a variety of cross sections.
• An interior or exterior wall may be adapted to act as a lens. That is the cross sectional shape of a drawn channel or drawn substrate is selected such that at least one wall forms a lens. For example, FIG. 4[0071]fshows a channel having a convex lens on one side and a concave lens on the other. This may be particularly useful in the case that an optical detector is employed. The curvature of the wall is selected to provide the appropriate focus or defocus of light passing through the wall. In contrast, a straight wall will produce minimal lensing effect, if any. The shape of the drawn channel may likewise be selected to maximize the sample volume or to alter the speed at which liquids flow through the drawn channel, for example. Likewise, a portion of the interior or exterior wall may act as a reflector. A particular shape may be selected to increase the reflectivity of the wall. However, in order to increase the reflectance of the wall over that caused by a change in index of refraction, the wall is preferably coated with a reflective coating, including but not limited to silver.
• FIG. 5[0072]a-eshow a series of end cap substrates for use with the drawn substrate. The end cap substrates can incorporate end cap channels, portals designed to provide fluidic communication with the drawn channels. The end caps substrates may include micro structures such as valves, switches, portals, mixing chambers or any other structures resulting in a lab on a chip device. Moreover, the end caps substrates may be terminal structures or may be used as an interface between a drawn micro channel array devices and the analytical instrument, as shown in the non-limiting examples illustrated in FIGS.7-10,17 and18, and described below.
• FIG. 5[0073]ashows anend cap substrate50 which simply includes eight straight,round endcap channels52. An end cap of this type may be manufactured in the same manner as the drawn substrate itself, and cut to the desired length. FIG. 5bshows anend cap substrate54 with threeendcap channels56. Eachchannel56 further incorporatesside ports58. While theend cap substrates54 andchannels56 can be made through the drawing process, theside ports58 require an additional machining step since they are, for example, perpendicular to the direction of draw. Similarly, FIG. 5cshows anend cap substrate60 with threeendcap channels62 and side ports orchannels64 which may be machined into theend cap substrate60. Unlike theside ports58 as shown in FIG. 5b, thechannels64 of FIG. 5care at the surface of theend cap substrate60 and thus eachchannel64 forms a semicircular trough. FIG. 5dshows anend cap substrate70 having threeendcap channels72. Eachchannel72 is tapered so that oneend74 is larger in diameter than the other end76. To produce a taperedport72, the tapered, or otherwise shaped, port may be formed by using a varied draw rate, mechanical machining, laser machining, or chemical etching. In order to create theend cap substrate70 as shown, with tapered ports, but with a uniform external cross section, the exterior may have to be machined. FIG. 5eshows a similar endcap with alarger volume taper78 which may serve as a capillary, pipette or as a reservoir. The endcap of FIG. 5ecan be formed, for example as two constant cross sections joined by a taper.
• FIGS. 6[0074]aand6bshow how an end cap substrate may be used in conjunction with a drawn substrate to produce a complete micro channel array device. In FIG. 6a, a drawnsubstrate80 contains three drawnchannels82, in this case, having a rectangular cross sectional geometry. Asection83 of one of thechannels82 is shown for illustrative purposes. At the end of each drawnchannel82, a machinedtransverse channel84 is provided. In a particular application, oneend86 of each transverse channel can be used as a waste port, while theother end88 acts as an analyte port. Anend cap substrate90 includes threechannels92 which are aligned with a central portion of the drawnchannels82 of the drawnsubstrate80. The threechannels92 of theend cap substrate90 act as buffer ports and are in fluid communication with thebuffer port88, thewaste port86, and the drawnchannel83 of the drawnsubstrate80. Theend cap substrate90 and drawnsubstrate80 are connected by any appropriate method including fusing and adhesive bonding. Since theend cap substrate90 and drawnsubstrate80 are similar in material and structure to optical fibers, many of the splicing techniques used in that field may be employed in the present invention.
• End caps substrates and endcap channels may also be used to provide flexibility in drawn channel path length as shown in FIG. 6[0075]b. A drawnsubstrate96 having several drawnchannels98 may be, for example, approximately 20 cm long. In some applications, such as capillary electrophoresis, it may be desirable to use a capillary having a length of 100 cm. By use of anend cap substrate100 on each end which redirects flow along adjacent drawnchannels98, five 20 cm drawn channels may provide the desired 100 cm length. Moreover, the same drawnsubstrate96 may be used to create, for example, two 40 cm drawn channels or one 40 cm and one 60 cm drawn channel by providing differentend cap substrates100.
• FIG. 7 shows a second end cap and drawn substrate combination.[0076]Drawn substrate100 incorporates four drawnchannels102, radially arrayed about a central axis. Each drawnchannel102 has an associatedconduit104 which may be machined or otherwise formed in theend106 of the drawnsubstrate100. For illustrative purposes, asection105 of one of the channels is shown. Anend cap substrate110 has four groups of threeendcap channels112 which may be machined or formed in a drawn end cap as discussed above. In one application, theendcap channels112 act as ports, allowing transport of material into thechannels102.
• FIGS. 8 and 9 show two alternate partial side views of the drawn micro channel array device of FIG. 7. In FIG. 8, the drawn[0077]substrate100 is shown with one of the drawnchannels102 and one of theconduits104. On one end is anend cap substrate110, with threeendcap channels112a-c. The first channel112amay be, for example, a buffer port, the second channel112b, may be an analyte port while thethird channel112cmay be a waste port. On the other end, a secondend cap substrate116 is provided with a throughhole118 corresponding to each drawnchannel102. In an alternate arrangement, shown in FIG. 9, the drawnsubstrate100′ contains only one portion of theconduit104′. Theother portion106 is instead formed in theend cap substrate110′. This is meant to demonstrate that the conduit can be machined or otherwise formed in either the endcap substrate or drawn substrate.
• As shown in FIG. 10, a more complicated drawn micro channel array device can be assembled from the basic parts. In the description of FIG. 10, the components are described without reference to the subsystems such as the actual channels, ports, slots and the like. Adjacent components are attached by fusing or bonding as appropriate.[0078]
• An[0079]end cap substrate140 acts as an interface to the analytical instrument section and contains ports and valves or valve regions. Next is a segment of drawnsubstrate144 which contains drawn channels which act as mixing chambers. The mixing chambers lead into anotherend cap unit148 which contains further valves. Thevalve section148 controls fluids as they enter the capillary electrophoresis (CE)section152. The capillary electrophoresis section includes drawn channels which act as capillaries for the CE process. The results of the CE process are read out by thedetector section156 which is preferably an end cap substrate which interfaces optically with the analytical instrument. Finally, anotherend cap substrate160 contains output and/or waste outlet structures and interfaces again to the analytical instrument. As is apparent from FIG. 10, a variety of structures may be built in similar fashion with various combinations of end cap substrates and drawn substrate.
• Optical fibers may be integrated with drawn micro channel array devices in a variety of ways. As shown in FIG. 11, a drawn micro[0080]channel array device170 having a central drawnchannel172 is suited to accept anoptical fiber174 within thechannel172. Arrayed around theoptical fiber174 are four drawnchannels176, each optically connected to anoptical fiber178. Theoptical fibers178 are attached to one or more detectors, not shown. The detectors may be any suitable light detector such as a photodiode, scintillator, thermodetector, photoelectric detector, pyroelectric detector, photomultiplier, phosphor screen, photoconductive detector, etc. As shown, theoptical fiber174 includes a radially emittingtip182.Photons184 emitted from thetip182 pass through thechannels176. In one application, if the channels contain a substance which fluoresces, thedetector fibers178 will carry the fluorescent light to the detectors. In an alternate application, the channels may be tested for a substance which blocks the photons from thetip182. In the presence of a signal from thedetector fibers178, the substance is absent. Other uses for this device may be apparent to those skilled in the art.
• In manufacturing the device of FIG. 11, the drawn micro[0081]channel array device170 is first manufactured according to the method described above. Thecentral channel172 may either be formed integrally with thedevice170, or may be later machined into thedevice170. The detectoroptical fibers178 are later added and are connecting by fusion splicing, mechanical coupling, or adhesives as appropriate.
• A similar arrangement to that of FIG. 11 is shown in FIG. 12. In this device, a[0082]device190 has several drawn or machinedchannels192 at its surface. Acentral channel194 again provides access for a sourceoptical fiber196 with an emittingtip198. Arrayed around theoptical fiber196 are four drawnchannels199, each optically connected to anoptical fiber200. Several detectoroptical fibers200 are arrayed within thechannels192 to transmit signals from the device to detectors, not shown. The channels at the surface act as a mechanical alignment and connection mechanism of theoptical fibers200 to thedevice190.
• FIGS. 13[0083]a-cshow three examples of how thephotons184 of FIG. 11 can be redirected. In FIG. 13a, anangled end300 on theoptical fiber301 acts as a side fire device, directing thephotons302 at an angle to the fiber axis (typically 90 degrees). The optical fiber ordevice303 can be rotated with respect to each other, thereby selecting the drawnchannels304 individually for analysis.
• FIG. 13[0084]bshows another device similar to FIG. 13a, only in this case areflector305, separate from theoptical fiber301 is provided for redirecting the light. The reflector is rotatable with respect to theoptical fiber306 anddevice307. The rotation allows selection of drawnchannels308 to be analyzed.
• FIG. 13[0085]cshows another device similar to FIG. 13a, having as a structure for redirecting light ascattering medium309, inserted in the central hole. The light is delivered to the device via theoptical fiber310 and the beam of photons is directed toward thescattering medium309 which scatters the photons towards the drawnchannels312. Though thescattering medium309 is shown to scatter in all directions, it could be arranged to scatter preferentially in one direction and be rotatable to select a given output channel as with the reflectors. Likewise, the reflectors and scattering medium could be replaced with any structure for redirecting light such as, for example, a diffractive optical element.
• Referring now to FIG. 14, an drawn[0086]substrate202 is shown with drawnchannels204 alongside drawnoptical waveguides206 embedded in the drawn substrate. This drawnsubstrate202 may be formed by first creating a preform body, not shown. The preform body contains bothchannels204, an embedded optical waveguide made of a similar material. The waveguide is formed by either a rod of lower refractive index than the surrounding preform body, or a rod which itself includes a central area of lower refractive index than an outer area on the rod. This difference in refractive index is necessary to achieve the condition of total internal reflection for waveguiding of the light. By drawing the preform body, the embedded optical waveguides are extended, forming drawnoptical waveguides206 and the channels are extended, forming drawnchannels204.
• FIG. 15[0087]aprovides a side view of anend cap substrate210 which may be used as a detector device. A pair ofoptical fibers212,214 are disposed within theend cap substrate210 and have end surfaces216 which are machined to present a 45° angle.Light211 enters thefirst fiber212, is reflected off the surface216 and is directed through a window portion of anendcap channel218. Light exiting or emitted from the endcap channel is reflected off the end surface216 and is then directed down fiber214 and exits fiber214 to the analytical instrument, not shown. Theendcap channel218 transports the analyte past the window betweenoptical fibers212 and214, where it is optically analyzed. FIG. 15amay be applied as shown in FIGS. 13a-cand FIG. 15bwherein the15adevice is attached to a drawn substrate219. The drawn substrate contains drawn channels where the analyte undergoes a CE process, for example, and subsequently travels intodevice217 where it undergoes optical analysis, as is done in a CE separation.
• FIG. 16 shows a drawn[0088]substrate220 having two drawnchannels222. Attached to one end of the drawnsubstrate220 is anend cap substrate230. The end cap contains extensions of the twochannels222, acentral hole232, and may be fused or otherwise adhered to the drawnsubstrate220. Twodetector fibers234 are disposed on either side of theend cap230 to accept light signals from the sides of theend cap230. Asource fiber236, having anemitter tip238, is used to input light signals into theend cap230 through thecentral hole232. Thechannels222 as shown are primarily disposed along a direction parallel to thearray220. However, portions of thechannels222 in theend cap230 extend in a direction perpendicular to the primary direction. These portions can serve, for example, to increase the overall length of the channels, or to increase the optical path length through which light emitted from theemitter tip238 must pass before being accepted by thedetector fibers234. This may be useful when the analyte being detected is only weakly interacting with the light signals due to low reactivity, low density, low concentration, low absorptivity, or other factors.
• Referring now to FIG. 17, a micro[0089]channel array device240 for capillary electrochromatography is made up of fourend caps substrates250,260,265,275 and a drawnsubstrate270. The firstend cap substrate265 is an injector cap similar to that shown in FIG. 5a-ewhich interfaces the device to the analytical instrument. The secondend cap substrate260 is a filter section end cap and likewise includes threeendcap channels262 and may be made by drawing. Additionally, filter material is disposed within theendcap channels262. Thethird endcap substrate250 is a detector section. Thedetector section250 includes threeendcap channels252 and is preferably made by drawing as described above. The fourthend cap substrate275 is an outlet interface similar to that shown in FIG. 5a-ewhich interfaces the device to the analytical instrument. Themicro channel array270 has three drawnchannels272 which are aligned on one end with thefilter ports262, and on the other end with thedetector ports252 so that they may be in fluidic communication. The drawnchannels272 form the electrochromatography columns through which an analyte will pass during analysis. As depicted in FIG. 17 the drawn channels are filled with a chromatographic media that is known to those skilled in the art. As illustrated, thechannels272 may also have tapered ends274 leading to thedetector section250. These tapered ends may be formed by varying the draw speed of the preform body during manufacture or by micromachining techniques as described earlier. The tapered ends274 serve to retain the aforementioned chromatographic media in the drawn substrate. The tapered ends274 may be placed in thethird endcap250 to serve the same purpose.
• FIG. 18 shows a completed micro[0090]capillary array device300 as could be used in a lab on a chip application. Thedevice300 includes aninsertion endcap substrate310, a drawnsubstrate320, and anoutlet endcap substrate330. Theinsertion endcap substrate310 serves as an interface to the instrument which dispenses the analyte and buffer, containsreservoirs302 for the analyte,buffer308 andanalyte waste306, and contains thevalve312 for dispensing the analyte into the drawnchannels314.Inlet electrodes303 are positioned at entrances to the inlets and theinlet ports305 are flared. The drawnsubstrate320 serves two functions in this example: analyte separation and detection. The outlet endcap330 substrate acts to route buffer and analyte into an interface with the analytical instrument.
• An example of a process of analyzing the analyte using the[0091]device300 shown in FIG. 18 can be described as follows: Buffer and analyte are dispensed into thereservoirs302,308 of the insertion endcap substrate via a 96 or 384 wellplate fluid dispenser316, for example, as is common in the industry. This 96 well plate fluid dispensing technology can be modified to incorporate theinlet electrodes303 required for applying the electrical fields discussed herein. Initially all device conduits are filled with buffer via differential pressure across thedevice300. Then the analyte is dispensed into theanalyte reservoir302 of theinsertion endcap substrate310 in preparation for injection. An electric field across the analyte reservoir and analyte waste reservoir draws a portion of the analyte into thevalve region312. This provides an injection of analyte into theseparation pathway314. Then an electric field is applied between thebuffer reservoir308 and thebuffer waste reservoir352 which initiates an electrophoretic separation of the analyte in the drawnchannel314. As the analyte migrates down the drawnchannel314 it passes through thedetection section322 allowing for quantification by spectrophotometric techniques. An interface between the drawnsubstrate detection section322 and thespectrophotometric instrument332 is accomplished in this example through an excitation optical fiber338 (which guide light from alight source336 into the drawn channel314) and an emission optical fiber340 (which guides light output from the drawn channel to the detector334). The analyzed materials and buffer then proceed into theoutlet endcap substrate330 which interfaces with theanalytical instrument350. This interface includes abuffer waste reservoir352, anoutlet electrode354, a differential pressure device356 (such as a vacuum) as a means of initially filling or subsequently rinsing all conduits, and amechanism358 providing a sealed connection into theoutlet endcap substrate330. Components of this interface may be integral to theoutlet endcap substrate330 itself.
• FIG. 19[0092]aand FIG. 19beach show partial cross sections of drawn array devices according to the present invention. FIG. 19aillustrates a drawnarray400 which contains a plurality of drawnchannels402 and a corresponding plurality oflenses404 formed in the array. Thelenses404 can be used, for example, to focus interrogating light onto the drawn channels for illuminating them, for inducing fluorescence, or other purposes known to those of skill in related arts. The drawnarray400 can be formed as the previously discussed arrays, by drawing a preform in the shape of the final array.
• FIG. 19[0093]bshows a drawnarray410 similar to the drawnarray400. Rather than including lenses, however, a curved portion including areflective surface412 is formed in the drawnarray410. The curved,reflective portion412 can be used, for example, to focus light on the channel. Though the curved portion is shown to be semicircular, it may likewise be hyperbolic to better focus light on the focal point. For further improvement, the two concepts may be used together so that lenses are formed on upper (for example) surfaces while reflectors are formed on lower surfaces. In this way, the light may be used with great efficiency.
• While the invention has been described in connection with what are presently considered to be the most practical and preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but on the contrary it is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the claims which follow.[0094]

Claims (37)

What is claimed is:

1. A device for analyzing a plurality of sample components, comprising:

a drawn substrate having a length, the drawn substrate having at least two drawn channels formed therein;

the drawn channels extending in a direction parallel to the length, and inlets and outlets in cooperating relation with the drawn channels.

2. A method of analyzing by introducing a plurality of sample components to a drawn substrate having a length, the drawn substrate having at least two drawn channels formed therein;

the drawn channels extending in a direction parallel to the length, and the substrate includes inlets and outlets disposed in cooperating relation with the drawn channels.

3. A device for analyzing a plurality of sample components, comprising:

a drawn substrate having a length, the drawn substrate having at least two drawn channels formed therein;

the drawn channels extending in a direction parallel to the length; and

at least one endcap substrate having at least one endcap channel, the at least one endcap channel being in fluid communication with at least one channel selected from the group comprising: a selected one of the drawn channels, a plurality of the drawn channels, another endcap channel and combinations thereof.

4. A device as inclaim 1 or3 with at least one drawn channel having a cross sectional area in the range of 0.0001 mm²to 1 mm², preferably 0.0025 mm²to 0.25 mm², and most preferably 0.005 mm²to 0.0075 mm².

5. A device as inclaim 1 or3 with at least one drawn channel having a length in the range of 1 mm to 1 km, preferably 3 mm to 1000 mm, and most preferably 10 mm to 250 mm.

6. A micro electro mechanical system utilizing a device as inclaim 1 or3.

7. A lab on a chip system utilizing a device as inclaim 1 or3.

8. A device as inclaim 1 or3, wherein the drawn substrate is formed using a drawing process in which one or more of draw rate, draw tensions, draw temperature, and draw pressure are varied such that a cross sectional area of each channel varies along the length.

9. A device as inclaim 1 or3, wherein the drawn channels further comprise a plurality of ports providing fluidic communication with the drawn channels.

10. A device as inclaim 1 or3, further comprising machined structures disposed within the substrate in cooperating relation with the drawn channels.

11. A device as inclaim 1 or3 wherein the drawn substrate further comprises an optical waveguide formed therein and extending in the direction parallel to the length.

12. A device as inclaim 1 or3 wherein the drawn substrate further comprises an electrical conductor extending in the direction parallel to the length.

13. A device as inclaim 1 or3 wherein the drawn substrate further comprises at least one optical isolator extending in the direction parallel to the length.

14. A device as inclaim 1, wherein a first one of the at least two drawn channels has a cross-sectional geometry different from a cross-sectional geometry of a second one of the at least two drawn channels.

15. A device as inclaim 1 wherein the drawn substrate comprises a material selected from the group comprising: glass, ceramic, and thermoplastic polymers.

16. A device as inclaim 1 wherein the drawn substrate comprises a material selected from the group comprising: fused silica, fused quartz, and PMMA.

17. A device as inclaim 1, further comprising an exterior coating on the drawn substrate comprising a material selected from the group comprising: polyimide, acrylate, fluorinated acrylate, silicone, metal, optical cladding.

18. A device as inclaim 1, further comprising an exterior coating on the drawn substrate comprising a material selected from the group which is: magnetic, radio opaque, optically filtering, conductive, dielectric.

19. A device as inclaim 1, further comprising an interior coating on the drawn channel comprising a material selected from the group comprising: hydrophobic bonded phases, hydrophyllic bonded phases, polyacrlyamides, silver, silver halide, gold, and polytetrafluoroethylene.

20. A device as inclaim 1, wherein at least a selected one of the at least two drawn channels has at least of a portion of a wall comprising a lens.

21. A device as inclaim 1, wherein at least a selected one of the at least two drawn channels has at least a portion of a wall comprising a reflector.

22. A device as inclaim 1, wherein the drawn substrate has at least one alignment groove on its exterior surface, down its length.

23. A device as inclaim 1, further comprising an optical fiber interfaced into one of the drawn channels.

24. A device as inclaim 23, further comprising a structure for redirecting light in the drawn channel interfaced with the optical fiber.

25. A device as inclaim 24, wherein the structure for redirecting light comprises a reflecting surface located on the end of the optical fiber interfaced into the drawn channel.

26. A device as inclaim 20, wherein the at least two drawn channels have a substantially constant spacing therebetween, a substantially constant relative rotational alignment and a substantially constant relative angular alignment along the length of the substrate.

27. A device as inclaim 26, wherein two of the drawn channels have a portion of a wall comprising a lens and the two lenses have a substantially constant spacing therebetween, a substantially constant relative rotational alignment and a substantially constant relative angular alignment along the length of the substrate.

28. A device as inclaim 3, wherein the endcap substrate is a drawn substrate and the endcap channels are drawn endcap channels.

29. A device as inclaim 28, wherein the drawn endcap channels are formed using a drawing process in which one or more of draw rate, draw tension, draw temperature and draw pressure are varied such that a cross sectional area of each channel varies along a length thereof.

30. A device as inclaim 3, wherein the endcap substrate further comprises an endcap channel having a cross-sectional geometry different from a cross-sectional geometry of the at least one endcap channel.

31. A device as inclaim 3, wherein the endcap substrate comprises a material selected from the group comprising: glass, ceramic, and thermoplastic polymers.

32. A device as inclaim 3, wherein the endcap substrate comprises a material selected from the group comprising: fused silica, fused quartz, and PMMA.

33. A device as inclaim 3, wherein the at least one endcap channel has at least a portion of a wall comprising a lens.

34. A device as inclaim 3, wherein the at least one endcap channel has at least a portion of a wall comprising a reflector.

35. A device as inclaim 3, wherein the drawn endcap has at least one alignment groove on its exterior surface.

36. A device as inclaim 3, wherein another endcap channel and at least one said endcap channel have a substantially constant spacing therebetween, a substantially constant relative rotational alignment and a substantially constant relative angular alignment along the length of the substrate.

37. A drawn substrate manufactured by a process comprising:

providing a preform body having at least one channel and at least one optical waveguide preform therein and extending along a length of the preform body;

drawing the preform body to extend the length thereof such that a length of the at least one channel is extended while substantially maintaining a cross sectional geometry of the at least one channel and such that a length of the at least one optical waveguide preform is extended while substantially maintaining a cross sectional geometry of the at least one optical waveguide preform; and

cutting the drawn preform body to a desired length.

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