US20070052757A1 - Electronically addressable microencapsulated ink and display thereof - Google Patents

Abstract

A system of electronically active inks is described which may include electronically addressable contrast media, conductors, insulators, resistors, semiconductive materials, magnetic materials, spin materials, piezoelectric materials, optoelectronic, thermoelectric or radio frequency materials. We further describe a printing system capable of laying down said materials in a definite pattern. Such a system may be used for instance to: print a flat panel display complete with onboard drive logic; print a working logic circuit onto any of a large class of substrates; print an electrostatic or piezoelectric motor with onboard logic and feedback or print a working radio transmitter or receiver.

Description

REFERENCE TO RELATED APPLICATIONS
• This application is a divisional of copending application Ser. No. 10/652,218, filed Aug. 29, 2003, which is a continuation of U.S. Ser. No. 10/200,571, filed Jul. 22, 2002 (now U.S. Pat. No. 6,652,075), which is a continuation of U.S. Ser. No. 09/471,604, filed Dec. 23, 1999 (now U.S. Pat. No. 6,422,687), which is a divisional of U.S. Ser. No. 08/935,800, filed Sep. 23, 1997 (now U.S. Pat. No. 6,120,588), which claims priority to U.S. Provisional Application No. 60/035,622, filed Sep. 24, 1996, and claims priority to and is a continuation-in-part of International Application PCT/US96/13469, filed Aug. 20, 1996, which claims priority to U.S. Provisional Application No. 60/022,222, filed Jul. 19, 1996, the entire disclosures of which applications are incorporated herein by reference in their entirety.
BACKGROUND OF INVENTION
• Currently, printing of conductors and resistors is well known in the art of circuit board manufacture. In order to incorporate logic elements the standard practice is to surface mount semiconductor chips onto said circuit board. To date there does not exist a system for directly printing said logic elements onto an arbitrary substrate.
• In the area of flat panel display drivers there exists technology for laying down logic elements onto glass by means of vacuum depositing silicon or other semiconductive material and subsequently etching circuits and logic elements. Such a technology is not amenable to laying down logic elements onto an arbitrary surface due to the presence of the vacuum requirement and the etch step.
• In the area of electronically addressable contrast media (as may be used to effect a flat panel display) emissive and reflective electronically active films (such as electroluminescent and electrochromic films), polymer dispersed liquid crystal films, and bichromal microsphere elastomeric slabs are known. No such directly electronically addressable contrast medium however is amenable to printing onto an arbitrary surface.
• Finally in the area of surface actuators electrostatic motors, which may be etched or non-etched, are known in the art. In the first case, such etched devices suffer from their inability to be fabricated on arbitrary surfaces. In the second case, non-etched devices suffer from the inability to incorporate drive logic and electronic control directly onto the actuating surface.
• It is an object of the present disclosure to overcome the limitations of the prior art in the area of printable logic, display and actuation.
SUMMARY OF THE INVENTION
• In general the present invention provides a system of electronically active inks and means for printing said inks in an arbitrary pattern onto a large class of substrates without the requirements of standard vacuum processing or etching. Said inks may incorporate mechanical, electrical or other properties and may provide but are not limited to the following function: conducting, insulating, resistive, magnetic, semiconductive, light modulating, piezoelectric, spin, optoelectronic, thermoelectric or radio frequency.
• In one embodiment this invention provides for a microencapsulated electric field actuated contrast ink system suitable for addressing by means of top and bottom electrodes or solely bottom electrodes and which operates by means of a bichromal dipolar microsphere, electrophoretic, dye system, liquid crystal, electroluminescent dye system or dielectrophoretic effect. Such an ink system may be useful in fabricating an electronically addressable display on any of a large class of substrate materials which may be thin, flexible and may result in an inexpensive display.
• In another embodiment this invention provides for a semiconductive ink system in which a semiconductor material is deployed in a binder such that when said binder is cured a percolated structure with semiconductive properties results.
• In another embodiment this invention for provides for systems capable of printing an arbitrary pattern of metal or semiconductive materials by means of photoreduction of a salt, electron beam reduction of a salt, jet electroplating, dual jet electroless plating or inert gas or local vacuum thermal, sputtering or electron beam deposition.
• In another embodiment this invention provides for semiconductor logic elements and electro-optical elements which may include diode, transistor, light emitting, light sensing or solar cell elements which are fabricated by means of a printing process or which employ an electronically active ink system as described in the aforementioned embodiments. Additionally said elements may be multilayered and may form multilayer logic including vias and three dimensional interconnects.
• In another embodiment this invention provides for analog circuits elements which may include resistors, capacitors, inductors or elements which may be used in radio applications or magnetic or electric field transmission of power or data.
• In another embodiment this invention provides for an electronically addressable display in which some or all of address lines, electronically addressable contrast media, logic or power are fabricated by means of a printing process or which employ an electronically active ink system as described in the aforementioned embodiments. Such display may further comprise a radio receiver or transceiver and power means thus forming a display sheet capable of receiving wireless data and displaying the same.
• In another embodiment this invention provides for an electrostatic actuator or motor which may be in the form of a clock or watch in which some or all of address lines, logic or power are fabricated by means of a printing process or which employ an electronically active ink system as described in the aforementioned embodiments.
• In another embodiment this invention provides for a wrist watch band which includes an electronically addressable display in which some or all of address lines, electronically addressable contrast media, logic or power are fabricated by means of a printing process or which employ an electronically active ink system as described in the aforementioned embodiments. Said watch band may be formed such that it has no external connections but rather receives data and or power by means of electric or magnetic field flux coupling by means of an antennae which may be a printed antennae.
• In another embodiment this invention provides for a spin computer in which some or all of address lines, electronically addressable spin media, logic or power are fabricated by means of a printing process or which employ an electronically active ink system as described in the aforementioned embodiments.
• Further features and aspects will become apparent from the following description and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
• The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention.
• FIGS.1A-F are schematic representations of means of fabricating particles with a permanent dipole moment.
• FIGS.2A-C are schematic representations of means of microencapsulation.
• FIGS.3A-E are schematic representations of microencapsulated electronically addressable contrast media systems suitable for top to bottom addressing.
• FIGS.4A-M are schematic representations of microencapsulated electronically addressable contrast media systems suitable for bottom addressing.
• FIGS.5A-D are schematic representations of microencapsulated electronically addressable contrast media systems based on a dielectrophoretic effect.
• FIGS.6A-B are schematic representations of microencapsulated electronically addressable contrast media systems based on a frequency dependent dielectrophoretic effect.
• FIGS.6C-E are plots of the dielectric parameter as a function of frequency for various physical systems.
• FIGS.7A-D are schematic representations of electronic ink systems and means for printing the same.
• FIG. 8 is a schematic representation of a laser reduced metal salt ink system.
• FIGS.9A-E are schematic representations of electronic ink systems and means for printing the same.
• FIGS.10A-C are schematic diagrams of printed transistor structures.
• FIG. 10D is a schematic diagram of a printed optoelectronic element.
• FIGS.10E-H are schematic diagrams of printed analog circuit elements.
• FIGS.11A-C are a schematic diagram of an electronic display employing printed elements which; this display may further include a data receiver or transceiver and a power means.
• FIG. 12 is a schematic diagram of an electrostatic motor which may be in the form of a watch or clock in which said electrostatic elements are printed.
• FIGS.13A-B are a schematic diagram of a watch in which the wristband of said watch incorporates an electronically addressable display having printed elements and which may further comprise wireless means for sending or receiving data or power between watch and watchband.
• FIG. 14 is a schematic diagram of a spin computer.
DETAILED DESCRIPTION
• Means are known in the prior art for producing bichromal particles or microspheres for use in electronic displays. Such techniques produce a particle that does not have an implanted dipole moment but rather relies in general on the Zeta potential of the material to create a permanent dipole. Such a scheme suffers from the fact that it links the material properties to the electronic properties thus limiting the size of the dipole moment which may be created.FIG. 1 details means of producing particles, either bichromal as might be used in an electrostatic display, or monochromal as might be used in a dielectrophoretic display, with an implanted dipole moment.
• Referring toFIG. 1A, atomizingnozzles1 are loaded withmaterials12 and13 which may be differently colored. A first atomizing nozzle may be held at apositive potential3 and a second nozzle may be held at anegative potential4. Such potentials aid in atomization and impart a charge to droplets which form from said nozzles producing positively charged droplets5 and negatively chargeddroplets6. Such opposite charged droplets are attracted to each other electrostatically forming an overall neutral pair. After the formation of a neutral pair there is no more electrostatic attraction and no additional droplets are attracted to the neutral pair. If saidmaterial12 and13 is such that the particles are liquid when exiting said nozzles and either cool to form a solid or undergo a chemical reaction which may involve an additional hardening agent to form a solid then said charge may be trapped on each side of said neutral pair forming a bichromal solid particle with an implanteddipole16. By suitable choice of materials such as polyethylene, polyvinylidene fluoride or other materials such metastable dipoles may persist for long periods of time as is known in the art of electrets. Aheating element7 may serve to reheat said pair thus minimizing surface tension energy and serving to reform said pair into a more perfect spherical shape. Finally a set ofelectrodes8 biased at either the same or opposite voltage may be employed to trap particles which are not overall charge neutral.
• Referring toFIG. 1B a similar apparatus may be employed to create a monochromal particle with an implanted dipole. In this arrangement nozzles containing material of thesame color12 are employed as before to create a monochromal particle with implanteddipole21.
• Referring toFIGS. 1C and 1D alternative means are shown for producing a bichromal particle with implanted dipole by means of combining two differentiallycolored materials12 and13 on aspinning disk11 or in a double barrelednozzle19. Said materials are charged by means ofpositive electrode14 andnegative electrode15 and combine by means of electrostatic attraction at the rim of said disk or exit of said double barrel nozzle to form bichromal particle with implanteddipole moment16. Said means differs from that known in the art by means of causing said twodifferent materials12 and13 to coalesce by means of electrostatic attraction as opposed to relying on surface properties and interactions between the two materials. Additionally the present scheme creates a particle with an implanteddipole moment16 which may serve to create a larger dipole moment than that possible from the naturally occurring Zeta potential.
• Referring toFIGS. 1E and 1F, a similar apparatus may be employed to create a monochromal particle with an implanted dipole. In this arrangement nozzles containing material of thesame color12 are employed as before to create a monochromal particle with implanteddipole21.
• A large number of techniques are known in the literature for microencapsulating one material inside of another material. Such techniques are generally used in the paper or pharmaceutical industry and do not generally produce a microcapsule which embodies simultaneously the properties of optical clarity, high dielectric strength, impermeability and resistance to pressure. With proper modification however these techniques may be made amenable to microencapsulating systems with electronic properties.
• Referring toFIG. 2A, aninternal phase25 may be a liquid or may be a solid with an additional associatedsurface layer27. Said internal phase if liquid or said associated surface layer may contain a polymer building block, such as adipoyl chloride in silicone oil. Said internal phase, with associated boundary layer in the case of a liquid, may then be dispersed in acontinuous phase liquid30 which may be an aqueous solution which is immiscible with said internal phase or associated surface layer. Finally asolution40 which contains another polymer building block or cross linking agent may be added tocontinuous phase liquid30. Saidsolution40 has the effect of forming a solid layer at the interface of the internal phase or associated surface layer and said continuous phase liquid30 thus acting to microencapsulate said internal phase.
• Referring toFIG. 2B aninternal phase25 which may be a solid or a liquid may be caused to pass through a series ofliquid films50,60,70 which may contain polymer building blocks, cross linking agents and overcoat materials such that afinal microcapsule120 results comprised of aninternal phase25, an associatedsurface layer27 and anouter shell80.
• An alternate means of microencapsulation is shown inFIG. 2C. In this scheme alight source82 which may be a UV light source passes in some areas through aphotomask84 exposing a crosslinkable polymer which may be caused to form acellular structure86. The individual cells of said cellular structure may then be filled with aninternal phase25.
• Employing the systems described in FIGS.2A-C it is possible to microencapsulate systems with electronically active properties specifically electronically addressable contrast media.FIG. 3 details such electronically addressable contrast media systems which are suitable for addressing by means of a topclear electrode100 andbottom electrode110. Referring toFIG. 3A amicrocapsule120 may contain a microsphere with a positively chargedhemisphere142 and a negatively charged140 hemisphere and an associatedsurface layer material130. If said hemispheres are differentially colored an electric field applied to said electrodes may act to change the orientation of said sphere thus causing a perceived change in color.
• Referring toFIG. 3B amicrocapsule120 may contain positively charged particles of onecolor210 and negatively charged particles of anothercolor220 such that application of an electric field to said electrodes causes a migration of the one color or the other color, depending on the polarity of the field, toward the surface of said microcapsule and thus effecting a perceived color change. Such a system constitutes a microencapsulated electrophoretic system.
• Referring to FIGS.3C-D, amicrocapsule120 may contain a dye, dye precursor or dye indicator material of a givencharge polarity230 or a dye, dye precursor or dye indicator material attached to a particle of given charge polarity such as a microsphere with an appropriate surface group attached and a reducing, oxidizing, proton donating, proton absorbing or solvent agent of theother charge polarity240 or a reducing, oxidizing, proton donating, proton absorbing or solvent agent attached to a particle of the other charge polarity. Under application of an electric field saiddye substance230 is maintained distal to said reducing, oxidizing, proton donating, proton absorbing orsolvent agent240 thus effecting one color state as inFIG. 3C. Upon de-application of said electric field said dye substance and said reducing, oxidizing, proton donating, proton absorbing or solvent agent may bond to form a complex245 of second color state. Suitable materials for use in this system are leuco and lactone dye systems and other ring structures which may go from a state of one color to a state of a second color upon application of a reducing, oxidizing or solvent agent or dye indicator systems which may go from a state of one color to a state of a second color upon application of a proton donating or proton absorbing agent as is known in the art. An additional gel or polymer material may be added to the contents of said microcapsule in order to effect a bistability of the system such that said constituents are relatively immobile except on application of an electric field.
• Referring toFIG. 3E, amicrocapsule120 may containphosphor particles255 and photoconductive semiconductor particles anddye indicator particles260 in asuitable binder250. Applying an AC electric field toelectrodes100 and110 causes AC electroluminescence which causes free charge to be generated in the semiconducting material further causing said dye indicator to change color state.
• Referring to FIGS.4A-M, it may be desirable to develop ink systems which are suitable for use without a toptransparent electrode100 which may degrade the optical characteristics of the device. Referring toFIGS. 4A and 4B, the chemistry as described in reference to FIGS.3C-D may be employed with in-plane electrodes such that said chemistry undergoes a color switch from one color state to a second color state upon application of an electric field to in-plane electrodes270 and280. Such a system is viewed from above and thus said electrodes may be opaque and do not effect the optical characteristics of said display.
• As another system in-plane switching techniques have been employed in transmissive LCD displays for another purpose, namely to increase viewing angle of such displays. Referring toFIGS. 4C and 4D a bistable liquid crystal system of the type demonstrated by Hatano et. al. of Minolta Corp. is modified to be effected by in plane electrodes such that a liquid crystal mixture transforms from a first transparentplanar structure290 to a second scattering focalconic structure292.
• Referring toFIG. 4E the system ofFIG. 3E may be switched by use of in-plane electrodes270 and280.
• Other systems may be created which cause a first color change by means of applying an AC field and a second color change by means of application of either a DC field or an AC field of another frequency. Referring to FIGS.4F-G, a hairpin shaped molecule or spring in theclosed state284 may have attached to it a positively charged282 and a negatively charged283 head which may be microspheres with implanted dipoles. Additionally one side of said hairpin shaped molecule or spring has attached to it aleuco dye286 and the other side of said hairpin shaped molecule or spring has attached to it a reducingagent285. When said molecule or spring is in theclosed state284 then saidleuco dye286 and said reducingagent285 are brought into proximity such that a bond is formed287 and said leuco dye is effectively reduced thus effecting a first color state. Upon a applying an AC electric field with frequency that is resonant with the vibrational mode of said charged heads cantilevered on said hairpin shaped molecule or spring saidbond287 may be made to break, thus yielding anopen state288. In said open state the leuco dye and reducing agent are no longer proximal and the leuco dye, being in a non-reduced state, effects a second color state. The system may be reversed by applying a DC electric field which serves to reproximate the leuco dye and reducing agent groups. Many molecules or microfabricated structures may serve as the normally open hairpin shaped molecule or spring. These may include oleic acid likemolecules289. Reducing agents may include sodium dithionite. The system as discussed is bistable. Energy may be stored in said hairpin shaped molecule or spring and as such said system may also function as a battery.
• Referring to FIGS.4I-K an alternative leucodye-reducing agent system may employ a polymer shown inFIG. 4I in anatural state293. When a DC electric field is applied said polymer assumes alinear shape294 withleuco286 and reducingagent285 groups distal from each other. Upon application of either a reversing DC field or an AC electric field said polymer will tend to coil bringing into random contact said leuco and reducing groups forming abond287 with a corresponding color change. Said polymer serves to make said system bistable.
• Referring toFIGS. 4L and 4M, a similar system is possible but instead polymer leuco and reducing groups may be attached to oppositely charge microspheres directly by means of abridge286 which may be a biotin-streptavidin bridge, polymer bridge or any other suitable bridge. As before application of a DC field cause leuco and reducing groups to become distal whereas application of a reverse DC field or AC field brings into random contact the leuco and reducing groups. A polymer may be added to aid in the stability of the oxidized state.
• Referring to FIGS.5A-D and FIGS.6A-B an entirely different principle may be employed in an electronically addressable contrast media ink. In these systems the dielectrophoretic effect is employed in which a species of higher dielectric constant may be caused to move to a region of high electric field strength.
• Referring toFIGS. 5A and 5B a non-colored dye solvent complex315 which is stable when no field is applied acrosselectrode pair150 may be caused to become dissociate intocolored dye300 and solvent310 components by means of anelectric field170 acting differentially on the dielectric constant of said dye complex and said solvent complex as applied byelectrode pair150. It is understood that the chemistries as discussed in the system ofFIG. 3C-D may readily be employed here and that said dye complex and said solvent complex need not themselves have substantially different dielectric constants but rather may be associated with other molecules or particles such as microspheres with substantially different dielectric constants. Finally it is understood that a gel or polymer complex may be added to the contents of said microcapsule in order to effect a bistability.
• Referring toFIG. 5C-D stacked electrode pairs150 and160 may be employed to effect a high electric field region in a higher170 or lower180 plane thus causing a higher dielectric constant material such as one hemisphere of abichromal microsphere141 or one species of a mixture of coloredspecies147 to migrate to a higher or lower plane respectively and give the effect of differing color states. Insuch schemes materials165 which may be dielectric materials or may be conducting materials may be employed to shape said electric fields.
• Referring to FIGS.6A-B, systems based on a frequency dependent dielectrophoretic effect are described. Such systems are addressed by means of applying a field of one frequency to produce a given color and applying a field of a different frequency to produce another color. Such a functionality allows for a rear addressed display.
• Referring toFIG. 6A, amicrocapsule120 encompasses aninternal phase184 which may be a material which has a frequency independent dielectric constant as shown inFIG. 6C,curve320 and which may have a first color B andmaterial182 which has a frequency dependent dielectric constant and a second color W. Said frequency dependent material may further have a high dielectric constant at low frequency and a smaller dielectric constant at higher frequency as shown inFIG. 6C,curve322. Application of a low frequency AC field by means ofelectrodes270 and280 causes saidmaterial182 to be attracted to the high field region proximal the electrodes thus causing said microcapsule to appear as the color B when viewed from above. Conversely application of a high frequency AC field by means ofelectrodes270 and280 causes saidmaterial184 to be attracted to the high field region proximal the electrodes thus displacingmaterial182 and thus causing said microcapsule to appear as the color W when viewed from above. If B and W correspond to Black and White then a black and white display may be effected. A polymer material may be added tointernal phase184 to cause said system to be bistable in the field off condition. Alternatively stiction to the internal side wall of said capsule may cause bistability.
• Referring toFIG. 6A,material182 andFIG. 6C, a particle is fabricated with an engineered frequency dependent dielectric constant. The means for fabricating this particle are depicted inFIGS. 1B, E and F. At low frequency such dipolar particles have sufficiently small mass that they may rotate in phase with said AC field thus effectively canceling said field and acting as a high. dielectric constant material. At high frequency however the inertia of said particles is such that they cannot keep in phase with said AC field and thus fail to cancel said field and consequently have an effectively small dielectric constant.
• Alternatively material182 may be comprised of naturally occurring frequency dependent dielectric materials. Materials which obey a frequency dependence functionality similar to the artificially created dipole material discussed above and which follow curves similar toFIG. 6C,curve322 include materials such as Hevea rubber compound which has a dielectric constant of K=36 at f=10³Hz and K=9 at f=10⁶Hz, materials with ohmic loss as are known in Electromechanics of Particles by T. B. Jones incorporated herein by reference and macromolecules with permanent dipole moments.
• Additionally material182 may be a natural or artificial cell material which has a dielectric constant frequency dependence as depicted inFIG. 6D, curve330 as are discussed in Electromechanics of Particles by T. B. Jones incorporated herein by reference. Such particles are further suitable for fabrication of an electronically addressable contrast ink.
• Referring toFIG. 6B, a system is depicted capable of effecting a color display.Microcapsule120 contains a particle of a first dielectric constant, conductivity andcolor186, a particle of a second dielectric constant, conductivity and color and an internal phase of a third dielectric constant, conductivity andcolor190. Referring toFIG. 6E it is known in the art of electromechanics of particles that for particles with ohmic loss (e.g. finite conductivity) at low frequency the DC conductivity governs the dielectric constant whereas at high frequency the dielectric polarization governs the dielectric constant. Thus a particle with finite conductivity has a dielectric constant K as a function of frequency f as inFIG. 6E,curve338. A second particle of second color has a dielectric constant K as a function of frequency f as inFIG. 6E,curve340. Finally an internal phase with no conductivity has a frequency independent dielectric constant K,curve336. If an AC field of frequency f1 is applied by means ofelectrodes270 and280,material186 of color M will be attracted to the high field region proximal to said electrodes thus causing said microcapsule to appear as a mixture of the colors C and Y, due to the other particle and internal phase respectively, when viewed from above. If an AC field of frequency f2 is applied by means ofelectrodes270 and280material188 of color Y will be attracted to the high field region proximal to said electrodes thus causing said microcapsule to appear as a mixture of the colors C and M when viewed from above. Finally if an AC field of frequency f3 is applied by means ofelectrodes270 and280internal phase190 of color C will be attracted to the high field region proximal to said electrodes thus causing said microcapsule to appear as a mixture of the colors M and Y when viewed from above. If C, M and Y correspond to Cyan, Magenta and Yellow a color display may be effected.
• It is understood that many other combinations of particles with frequency dependent dielectric constants arising from the physical processes discussed above may be employed to effect a frequency dependent electronically addressable display.
• In addition to the microencapsulated electronically addressable contrast media ink discussed inFIGS. 3-6,FIGS. 7-9 depict other types of electronically active ink systems. In the prior art means are known for depositing metals or resistive materials in a binding medium which may later be cured to form conducting or resistive traces. In the following description novel means are described for depositing semiconductive materials in a binder on a large class of substrate materials in one case and for depositing metals, resistive materials or semiconductive materials outside of vacuum, in an arbitrary pattern, without the need for an etch step and on a large class of substrate materials in another case.
• In one system asemiconductor ink350 may be fabricated by dispersing asemiconductor powder355 in asuitable binder356. Said semiconductor powder may be Si, Germanium or GaAs or other suitable semiconductor and may further be with n-type impurities such as phosphorus, antimony or arsenic or p-type impurities such as boron, gallium, indium or aluminum or other suitable n or p type dopants as is known in the art of semiconductor fabrication.Said binder356 may be a vinyl, plastic heat curable or UV curable material or other suitable binder as is known in the art of conducting inks. Saidsemiconductive ink350 may be applied by printing techniques to form switch or logic structures. Said printing techniques may include afluid delivery system370 in which one ormore inks372,374 may be printed in a desired pattern on to a substrate. Alternatively saidink system350 may be printed by means of ascreen process377 in which anink380 is forced through a patternedaperture mask378 onto asubstrate379 to form a desired pattern. Saidink pattern360 when cured brings into proximity saidsemiconductive powder particles355 to create a continuous percolated structure withsemiconductive properties365.
• Referring toFIG. 8 a system is depicted for causing a conductive orsemiconductive trace390 to be formed onsubstrate388 in correspondence to an impinginglight source382 which may be steered by means of anoptical beam steerer384. The operation of said system is based upon amicrocapsule386 which contains a metal or semiconductive salt in solution. Upon being exposed to light382 which may be a UV light said metal or semiconductive salt is reduced to a metal or semiconductor and said microcapsule is simultaneously burst causing deposition of a conductive or semiconductive trace.
• Referring toFIG. 9A, an ink jet system for depositing metallic or semiconductive traces410 is depicted. In this system a jet containing a metal orsemiconductive salt420 impinges uponsubstrate400 in conjunction with a jet containing a reducingagent430. As an example, to form a metallic trace silver nitrate (AgNO₃) may be used forjet420 and a suitable aldehyde may be used for the reducingjet430. Many other examples of chemistries suitable for the present system are known in the art of electroless plating. In all such examples it is understood that said jets are moveable and controllable such that an arbitrary trace may be printed.
• Referring toFIG. 9B a system which is similar to that ofFIG. 9A is depicted. In this case anelectron beam470 may be used instead of said reducing jet in order to bring about a reduction of a metal or semiconductive salt emanating from ajet460. Aground plane450 may be employed to ground said electron beam.
• Referring toFIG. 9C an ink jet system for depositing a metallic or semiconductive trace is depicted based on electroplating. In this system a metal or semiconductive salt in ajet480 held at a potential V may be electroplated onto asubstrate410 thus forming a metallic or semiconductive trace.
• Referring toFIG. 9D means are known in the prior art for UV reduction of a metal salt from an ink jet head. In the present system a jet containing a metal orsemiconductive salt490 may be incident upon asubstrate400 in conjunction with a directedlight beam495 such that said metal or semiconductive salt is reduced into a conductive orsemiconductive trace410. Alternativelyjet490 may contain a photoconductive material and a metal salt which may be caused to be photoconductively electroplated ontosurface400 by means of application oflight source495 as is known in the field of photoconductive electroplating.
• Referring toFIG. 9E a system is depicted for amoveable deposition head500 which contains achamber520 which may be filled with an inert gas viainlet510 and which further contains thermal, sputtering, electron beam or other deposition means530. Saidmoveable head500 may print a metal, semiconductor, insulator, spin material or other material in an arbitrary pattern onto a large class ofsubstrates540. In some casesuch substrate540 be cooled or chilled to prevent damage from said materials which may be at an elevated temperature.
• Referring toFIG. 10 said previously described electronically active ink systems and printing means may be applied to form switch or logic structures, optoelectronic structures or structures useful in radio or magnetic or electric field transmission of signals or power. As indicated in FIGS.10A-B an NPN junction transistor may be fabricated consisting of a n-type emitter950, a p-type base954 and a n-type collector952.
• Alternatively a field effect transistor may be printed such as a metal oxide semiconductor. Such a transistor consists of a p-type material970, an n-type material966 an n-type inversion layer968 anoxide layer962 which acts as the gate asource lead960 and adrain lead964. It is readily understood that multiple layers of logic may be printed by using an appropriate insulating layer between said logic layers. Further three dimensional interconnects between different logic layers may be accomplished by means of vias in said insulating layers.
• Referring toFIG. 10D a printed solar cell may be fabricated by printing some or all of ametal contact layer972, a p-type layer974, ann type layer976 and an insulatinglayer978.Light979 which impinges upon said structure generates a current as is known in the art of solar cells. Such printed solar cells may be useful in very thin compact and/or inexpensive structures where power is needed.
• Referring to FIGS.10E-H elements useful for analog circuitry may be printed. Referring toFIG. 10E a capacitor may be printed withdielectric material983 interposingcapacitor plates981 and985. Alternatively the same structure may constitute a resistor by replacing dielectric983 with a resistive material such as carbon ink.
• Referring to FIGS.10F-H inductors, chokes or radio antennae may be printed layer by layer. Referring toFIGS. 10F and G a first set ofdiagonal electrodes989 may be laid down on a substrate. On top of this may be printed an insulator ormagnetic core987. Finallytop electrodes992 which connect with said bottom electrodes may be printed this forming an inductor, choke or radio antennae. An alternate in-plane structure is shown inFIG. 10H in which theflux field995 is now perpendicular to the structure.
• The ink systems and printing means discussed in the foregoing descriptions may be useful for the fabrication of a large class of electronically functional structures.FIGS. 11-14 depict a number of possible such structures which may be fabricated.
• Referring toFIG. 11A, an electronic display, similar to one described in a copending patent application Ser. No. 08/504,896, filed Jul. 20, 1995 by Jacobson (now U.S. Pat. No. 6,124,851), is comprised of electronicallyaddressable contrast media640,address lines610 and620 andlogic elements670 all or some of which may be fabricated with the ink systems and printing means as described in the foregoing descriptions. Said Electronic Display may additionally comprise a data receiver ortransceiver block672 and apower block674. Said data receiver block may further be a wireless radio receiver as pictured inFIG. 11B in which some or all of the components thereof includingantennae676, inductor or choke678, diode,680,capacitor682,NPN transistor684,resistor681, conductingconnection677 orinsulation overpass675 may be printed by the means discussed above. Alternatively said data receiver or transceiver block may be an optoelectronic structure, a magnetic inductive coil an electric inductive coupling or an acoustic transducer such as a piezoresistive film.
• Saidpower block674 may comprise a printed polymer battery as pictured inFIG. 11C which consists of in one instance alithium film686, a propylene carbonate LiPF₆film688 and LiCoO₂inmatrix690. Said power block may alternatively consist of any other battery structure as known in the art of thin structure batteries, a magnetic or electric inductive converter for means of power reception as known in the art, a solar cell which may be a printed solar cell or a semiconductive electrochemical cell which may further have an integral fuel cell for energy storage or a piezoelectric material which generates power when flexed.
• Such adisplay600 as described above further comprising a data receiver ortransceiver672 andpower block674 in which some or all of said components are printed may comprise an inexpensive, lightweight, flexible receiver for visual data and text which we may term “radio paper.” In such a system data might be transmitted to the “radio paper” sheet and there displayed thus forming a completely novel type of newspaper, namely one which is continuously updated.
• Referring toFIG. 12 an electrostatic motor which may form an analog clock or watch is depicted which consists of printed conductingelements720,730,740 and760 which are printed ontosubstrate700. Said elements, when caused to alternately switch between positive negative or neutral states by means of alogic control circuit710 may cause anelement750 to be translated thus forming a motor or actuator. In the device ofFIG. 12 some or all of said conducting elements and/or logic control elements may be printed using the ink systems and printing means described in the foregoing description.
• Referring toFIG. 13A awrist watch800 is depicted in which theband820 of said watch contains an electronicallyaddressable display830 in which some or all of the components of said display, including the electronically addressable contrast media, the address lines and/or the logic are fabricated by means of the ink systems and printing means described in the foregoing description. Such a fabrication may be useful in terms of producing an inexpensive, easily manufacturing and thin display function.Control buttons810 may serve to control aspects of saiddisplay830.
• Referring toFIG. 13B it is presently a problem to transmit data or power to a watch band via a wire connection as such connections tend to become spoiled by means of motion of the watchband relative to the watch. In order to overcome thisFIG. 13B describes a system in which a magnetic orelectric inductor832 inwatch band820 may receive or transmit power or data to a magnetic orelectric inductor834 inwatch800 thus eliminating said wired connection. Saidinductor832 and834 may be printed structures.
• Referring toFIG. 14, a spin computer is depicted in whichdipoles912 withdipole moment914 are situated at the nodes ofrow920 andcolumn930 address lines. Such a computer works by means of initially addressing said dipoles to an initial condition by said address lines and then allowing dipole interactions to produce a final state of the system as a whole thus performing a calculation as is known in the art of Spin Ising models and cellular automata. Said dipoles may consist of adipolar microsphere912 microencapsulated in amicrocapsule910 or may consist of another form of dipole and/or another means of encapsulation.
• While this invention has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (18)

1. A movable head for printing an electrically active material, the head comprising:

(a) an inert gas chamber; and

(b) a thermal, sputtering, or electron beam for depositing the material.

2. An inkjet apparatus comprising a movable head according toclaim 1 in combination with means for changing the temperature of a substrate.

3. An inkjet apparatus according toclaim 2 further comprising means for generating a beam of ultraviolet radiation.

4. An electro-optic display component comprising a molecule having:

(a) a first portion with a first charge; and

(b) a second portion with a second charge whereby the application of an electric field, or a frequency change in such a field, changes the perceived optical state of said molecule.

5. An electronic display component according toclaim 4 manufactured by a process comprising:

(a) providing a radiation-curable substrate;

(b) imagewise exposing said radiation-curable substrate to a radiation source, thereby forming a plurality of individual cells in said radiation-curable substrate; and

(c) filling at least one of said plurality of individual cells with a contrast medium comprising a suspending fluid and said molecule, thereby said filled cell forms said electronic display component.

6. An electronic display component according toclaim 4 in combination with electric field generation means arranged to apply at least one of a DC field and an AC field to said component.

7. An electro-optic display component comprising a microcavity filled with a suspending fluid and a microfabricated structure, said structure having:

(a) a first part with a first charge; and

(b) a second part with a second charge whereby the application of an electric field, or a frequency change in such a field, changes the perceived optical state of said structure.

8. An image display operating by electrophoretic or dielectrophoretic principle wherein a charged particle species is replaced by a microfabricated structure having a first part with a first charge and a second part with a second charge.

9. An electronic display component according toclaim 8 in combination with electric field generation means arranged to apply at least one of a DC field and an AC field to said display.

10. A printable semiconductor ink comprising a semiconductor powder dispersed in a binder.

11. A printable semiconductor ink according toclaim 10 wherein the semiconductive powder comprises any one or more of silicon, germanium, gallium arsenide, phosphorus, antimony, arsenic, boron, gallium, indium, aluminum, a p-type dopant and an n-type dopant.

12. A printable semiconductor ink according toclaim 10 wherein the binder comprises a vinyl, heat-sensitive or ultra-violet sensitive polymer.

13. A substrate coated with a semiconductor ink according toclaim 10.

14. A logic structure for a flat panel display comprising a semiconductor ink according toclaim 10.

15. A flat panel display comprising a logic structure according toclaim 14.

16. An electronic device comprising the flat panel display ofclaim 15.

17. A printer cartridge or printer supply comprising a semiconductor ink according toclaim 12.

18. A battery, solar cell, antenna, or computer produced by a method according toclaim 12.

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