JPWO2019098279A1 - Flexible electronic device - Google Patents

Abstract

The present inventors have a first conductive substance selected from a conductive carbon material, a conductive polymer, or metal nanoparticles and a second conductive substance on the surface of an arbitrary substrate such as a glass substrate or a polymer film substrate. By laminating and printing conductive wiring formed from a conductive material, a thin-film device capable of being injected into a living body having a total thickness of the laminated conductive wiring layer and the polymer thin film of less than 100 μm was completed. .. By using this device, it is possible to provide an antenna coil having flexibility that allows passage through the tube of an injection needle and a flexible electronic device that can be bent as a microelectrode.

Description

The present invention relates to a flexible electronic device and a method for manufacturing the same.

Wireless power feeding, which uses electromagnetic induction or resonance to generate electromotive force in a coil, enables power to be supplied to a device without mediating a wire. Therefore, by implanting and indwelling a conductive device in the living body, it can be used as an antenna coil or microelectrode, wirelessly fed, and sustained drug release by Joule heat, and a light source in photodynamic therapy and optogenetics. It is also expected to be applied to an excitation light source for bioimaging (Non-Patent Documents 1 and 2). It is expected that such a conductive device will be used to control life functions by light (Non-Patent Document 1). However, conventional implantable devices in vivo are invasive with measures such as skin and tissue incisions and laparotomy. In addition, a clean room is required for the treatment, and the equipment is expensive.

Therefore, a device form that can be stored in a medical device such as an endoscope, a catheter, or an injection needle and ejected into a living body is less invasive to the living body and does not necessarily require equipment such as a crane room. It is extremely important for expanding the convenience of the device.

In particular, in recent years, bioimplantable devices that can be injected and implanted in a living body without destroying the structure of soft and fragile living tissue have attracted attention (Non-Patent Documents 2 and 3). However, conventional devices are still thick (thickness> 50 μm) even if they are thin films, and highly invasive laparotomy or the like is required for implantation in a living body (Non-Patent Document 2). ..

S. H. Yun and S. J. J. Kwok, Nature Biomed. Eng., 1, Article No.0008 (2017) Hu Tao et al., PNAS, 111 (49), 17385-17389 (2014) K.S. Novoselov, et al., Science, 306, 666-669 (2004)

An object of the present invention is to provide a foldable flexible electronic device as a conductive device that can be stored in a medical device such as an endoscope, a catheter or an injection needle and injected into a living body.

The present inventors have studied diligently, and on the surface of any base material such as a glass base material or a polymer film base material, a conductive organic material selected from a conductive carbon material or a conductive polymer, or metal nanoparticles. Using a conductive ink containing a plurality of types of conductive materials selected from the conductive materials formed from, a laminated conductive wiring layer laminated as a conductive wiring layer is printed, and a polymer thin film and a sacrificial film or a support are obtained. After the film was further laminated, it was peeled off from the base material to complete a thin-film flexible electronic device that can be injected into a living body in which the total thickness of the laminated conductive wiring layer and the polymer thin film is less than 100 μm. Furthermore, using the flexible electronic device, a flexible and bendable antenna coil and microelectrodes that can be injected and embedded in a living body without a large skin incision have been completed.

Specifically, the present invention provides a polymer thin film having a film thickness of 10 nm or more and less than 50 μm, and
The non-easy-to-peel conductive wiring layer formed on the polymer thin film and the easy-to-peel easily peelable than the non-easy-to-peel conductive wiring layer formed on the non-easy-to-peel conductive wiring layer. Conductive wiring, including a laminated conductive wiring layer having a conductive wiring layer
Have,
Provided is a flexible electronic device in which the total film thickness of the laminated conductive wiring layer and the polymer thin film is less than 100 μm.

In the flexible electronic device of the present invention, the non-peelable conductive wiring layer may be composed of metal nanoparticles.

In the flexible electronic device of the present invention, the peelable conductive wiring layer may be composed of a multi-layer structure or a structure in which particles are aggregated or aggregated.

In the flexible electronic device of the present invention, the easily peelable conductive wiring layer may be a conductive wiring layer formed of a conductive organic material.

In the flexible electronic device of the present invention, the easily peelable conductive wiring layer may be graphene or PEDOT: PSS.

In the flexible electronic device of the present invention, the ratio of the maximum width in the bent direction when the conductive wiring layer is expanded to the maximum area and the maximum width in the bent direction when bent (width when expanded / The width when folded) may be 5 or more.

The flexible electronic device of the present invention may be a foldable electronic device.

The flexible electronic device of the present invention may further have an insulating protective layer that coats the laminated conductive wiring layer on the polymer thin film.

The flexible electronic device of the present invention may be an electronic device for injection from outside the living body into the living body.

In the flexible electronic device of the present invention, the conductive wiring may form an electronic circuit.

In the flexible electronic device of the present invention, the conductive wiring may form a coil or an electrode in the electronic circuit.

In the flexible electronic device of the present invention, the coil may be an antenna coil.

In the flexible electronic device of the present invention, the resistivity of the conductive wiring may be 100 × 10 ^-7 Ωm or less.

The flexible electronic device of the present invention is a light source or an integrated circuit electrically connected to a pair of terminals arranged at both ends of the conductive wiring on a film surface of the polymer thin film provided with the laminated conductive wiring layer. The conductive wiring and the outer surface of the element may be coated with an insulating protective layer.

In the flexible electronic device of the present invention, the polymer thin film may be a self-supporting polymer thin film.

In the flexible electronic device of the present invention, the conductive organic material is selected from a conductive carbon material or a conductive polymer.
The conductive carbon material is selected from conductive carbon black, carbon nanotubes, carbon nanotube derivatives, graphene, graphite, and conductive carbon fibers.
The conductive polymer is polythiophene, polypyrrole, polyaniline, polyazulene, polyindole, polycarbazole, polyacetylene, polyfuran, polyparaphenylene vinylene, polyazulene, polyparaphenylene, polyparaphenylene sulfide. , Polyisotianaphene or polythiazyl,
The metals in the metal nanoparticles are from gold, platinum, silver, copper, nickel, rhodium, palladium, magnesium, chromium, titanium, iron and their oxides, and alloys of these metals and / or their oxides. May be selected.

The flexible electronic device of the present invention may be used as a power receiving device and / or a power transmitting device in a wireless power feeding system.

Further, the present invention is a method for manufacturing a flexible electronic device.
(i) A step of forming the first conductive wiring layer by printing the first conductive ink containing the first conductive material on the base material, and
(ii) By printing on the base material and the first conductive wiring layer with a second conductive ink containing the second conductive material, on the first conductive wiring layer. A step of forming a laminated conductive wiring layer in which a second conductive wiring layer is laminated, and
(iii) A step of coating the laminated conductive wiring layer with a polymer thin film
(iv) The laminated conductive wiring layer coated with the polymer thin film is peeled off from the first conductive wiring layer or in the first conductive wiring layer, and is laminated on the film surface of the polymer thin film. Provided is a method for manufacturing a flexible electronic device including a step of transferring a conductive wiring layer and forming a conductive wiring.

In the manufacturing method of the present invention
Process (iv) is
(iv') The step of coating the polymer thin film with a water-soluble support film and
(v') The laminated conductive wiring layer coated with the polymer thin film and the water-soluble support film is peeled off from between the first conductive wiring layer and the base material or in the first conductive wiring layer. The transfer step of transferring the laminated conductive wiring layer to the film surface of the polymer thin film, and
(vi') A step of immersing the structure composed of the polymer thin film, the water-soluble support film, and the laminated conductive wiring layer in water to dissolve and remove the water-soluble support film may be included.

In the production method of the present invention, after the step (vi'), further
(vii') An insulating protective layer is coated on the transfer surface of the laminated conductive wiring layer to which the laminated conductive wiring layer of the polymer thin film is transferred and / or the film surface of the polymer thin film opposite to the laminated conductive wiring layer. It may include a sealing step.

The manufacturing method of the present invention may include a step of heat-treating the laminated conductive wiring layer at 80 ° C. or higher and 400 ° C. or lower after the step (ii) and before the step (iii).

In the production method of the present invention, the polymer thin film may be a self-supporting polymer thin film.

In the production method of the present invention, the non-peelable conductive wiring layer may be composed of metal nanoparticles.

In the production method of the present invention, the easily peelable conductive wiring layer may be composed of a multi-layer structure or a structure in which particles are aggregated or aggregated.

In the manufacturing method of the present invention, the easily peelable conductive wiring layer may be a conductive wiring layer formed of a conductive organic material.

In the production method of the present invention, the conductive organic material is selected from a conductive carbon material or a conductive polymer.
The conductive carbon material is selected from conductive carbon black, carbon nanotubes, carbon nanotube derivatives, graphene, graphite, and conductive carbon fibers.
The conductive polymer is polythiophene, polypyrrole, polyaniline, polyazulene, polyindole, polycarbazole, polyacetylene, polyfuran, polyparaphenylene vinylene, polyazulene, polyparaphenylene, polyparaphenylene sulfide. , Polyisotianaphene or polythiazyl,
The metals in the metal nanoparticles are from gold, platinum, silver, copper, nickel, rhodium, palladium, magnesium, chromium, titanium, iron and their oxides, and alloys of these metals and / or their oxides. May be selected.

In the manufacturing method of the present invention, the conductive wiring may be a coil or an electrode, and may be an antenna coil when the coil is used.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a bendable flexible electronic device as a conductive device that can be stored in a medical device such as an endoscope, a catheter or an injection needle and injected into a living body.

The schematic diagram of the printing and peeling method of an antenna coil. The schematic diagram of the manufacturing method of the printed wiring peeled off by a polymer support film. Cross-sectional profile of the laminated conductive wiring layer before and after peeling by the polymer support film. “Au / Graphene” and “Graphene” represent the measurement results before peeling, and “Graphene left on glass” represents the measurement results after peeling. The figure which shows the applicability in the drug sustained-release and LED light emission in the medical field of the flexible electronic device of this invention. The figure which shows the applicability in cardiac pacing combined with the transplantation of light-sensitive cells by optogenetics of the flexible electronic device of this invention. The figure which shows the Raman spectrum of graphene on the base material side and the support film side. A: A spectrum showing the peak of graphene remaining on the glass substrate. B: A spectrum showing the peak of graphene transferred to the film. For both A and B, the upper row: 1000-3000 cm ^-1 spectrum diagram. Bottom: Spectral diagram from 2550 to 2750 cm ^-1. The figure which shows the frequency characteristic of a light emitting device. The figure which shows the light emission experiment of LED, the distance dependence, and the frequency response characteristic. Photographs during the experiment to explain the experimental method. The figure which shows the measurement result of the relationship between a feeding distance and an illuminance. The results are shown when the resonance frequency is 30 MHz, the potential difference is 20 Vp-p, and the power amplification factor is doubled. Photograph of the device housed in a gelatin capsule (diameter: 8.6 mm). The results are shown when the feeding frequency is 30 MHz, the potential difference is 20 Vp-p, and the power amplification factor is doubled. Photograph of an injection experiment of wiring (antenna coil) with a syringe. (1) Photograph of the bent electronic device of the present invention taken into a syringe before injection. (2) The photograph figure which extrudes the plunger of a syringe and ejects the electronic device of this invention. (3) Photograph of the electronic device of the present invention injected out of the syringe. (4) The photograph figure of the electronic device of this invention which was ejected to the outside of a syringe and expanded. The photograph which arranged the electronic device which has the LED light emitting element of this invention which has a protective film in a phosphate buffer solution (pH 7.4), and showed that it operates normally by wireless power feeding. Fluorescence micrograph of mouse skeletal myoblasts (C2C12) expressing photoresponsive channel protein (ChR2) and green fluorescent protein (Venus) was irradiated with blue light and fluorescence of green fluorescent protein (Venus) was observed. .. A: Phase difference image, B: Green image from LED under blue light irradiation, C: Green image from LED under blue light irradiation.

1. 1. Flexible Electronic Device One of the embodiments of the present invention is a flexible electronic device.

The flexible electronic device of the present invention has a polymer thin film and a laminated conductive wiring layer in which at least two or more kinds of conductive materials are laminated on at least one film surface of the polymer thin film, and has at least one kind of conductivity. A flexible electronic device formed by peeling off a sex material.

More specifically, the flexible electronic device of the present invention
Polymer thin films with a film thickness of 10 nm or more and less than 50 μm, and
The non-easy-to-peel conductive wiring layer formed on the polymer thin film and the non-easy-to-peel conductive wiring layer formed on the non-easy-to-peel conductive wiring layer are physically easier to peel than the non-easy-to-peel conductive wiring layer. Conductive wiring, including a laminated conductive wiring layer having a conductive wiring layer
Have,
A flexible electronic device in which the total film thickness of the laminated conductive wiring layer and the polymer thin film is less than 100 μm.

In the present specification, "having a easily peelable conductive wiring layer that is physically easier to peel than the non-peeling conductive wiring layer" is defined by the non-peeling conductive wiring layer and the easily peelable conductive wiring layer. Easy-to-peel conductive wiring that is relatively easy to peel off compared to non-easy-to-peel conductive wiring layers when a physical force is applied to the formed laminated conductive wiring layers in the direction of separating the layers. It means that the layer is peeled off.

Therefore, the conductive wiring in the flexible electronic device of the present invention includes the non-peeling conductive wiring layer formed on the polymer thin film and the easily peelable conductive wiring layer formed on the non-peeling conductive wiring layer. When the laminated conductive wiring layer having the above is peeled off, it is peeled off from the easily peelable conductive wiring layer or in the easily peelable conductive wiring layer, so that the residual layer that is not peeled off in the easily peelable conductive wiring layer It is a conductive wiring including a laminated conductive wiring layer in which a non-peelable conductive wiring layer is laminated.

Further, as a more specific example of the flexible electronic device of the present invention, a polymer thin film and a laminated conductive wiring layer in which at least two or more kinds of conductive materials are laminated on at least one film surface of the polymer thin film. Examples thereof include a foldable flexible electronic device having an insulating protective layer that coats the laminated conductive wiring layer on the polymer thin film.

In particular, when the flexible electronic device of the present invention is bent, even if metal nanoparticles having a high possibility of disconnection are used as a material for the conductive wiring layer, the conductive wiring has a multilayer structure formed by various types of conductive wiring layers. Therefore, there is an advantage that the conductive wiring without electrical defects can be obtained, such that the conductive wiring as a whole is hard to be broken.

In the present specification, "foldable" means that a container (capsule) is stored in a microtubule (injection needle, catheter, endoscopic trocar) or a container (capsule) by a folding operation, a folding operation, and / or a rolling operation. , It means that it has a property that can be processed to make it a shape that can be released afterwards.

In the flexible electronic device of the present invention, the laminated conductive wiring layer is, for example, a conductive ink for forming a non-peeling conductive wiring layer and a conductive ink for forming a non-peeling conductive wiring layer. It is a laminated conductive wiring layer laminated by printing.

As an example of the method for manufacturing the flexible electronic device of the present invention,
A step of forming a laminated conductive wiring layer for forming a laminated conductive wiring layer by laminating a conductive carbon material, a conductive polymer, or a material selected from metal nanoparticles on a base material such as glass or a polymer thin film.
The laminated conductive wiring layer is coated with a polymer thin film and further a water-soluble support film, and the laminated conductive wiring layer coated with the polymer thin film is formed from or within the conductive organic material layer. A transfer step of peeling and transferring the conductive wiring layer to the film surface of the polymer thin film,
A step of dissolving the water-soluble support film by immersing the laminate of the polymer thin film, the water-soluble support film, and the conductive wiring formed by the conductive wiring layer in water.
Insulation that coats and seals an insulating protective layer on the transfer surface of the laminated conductive wiring layer to which the laminated conductive wiring layer of the polymer thin film is transferred and / or the film surface of the polymer thin film opposite to the laminated conductive wiring layer. A manufacturing method including a protective layer forming step can be mentioned.

Further, the flexible electronic device of the present invention volatilizes or volatilizes a component contained in the conductive material as an additive such as a surfactant, a dispersant, a moisturizer or an adhesion enhancer by including a heat treatment step in the manufacturing process thereof. By decomposing, a conductive layer can be constructed as a highly pure conductive material. Such a high-purity conductive material has an electrical resistivity of 100 × 10 ^-7 Ω ・ m or less, preferably 10 × 10 ^-7 Ω ・ m or less, and more preferably 6 × 10 ^-7 Ω ・ m or less. Has a conductive layer of.

More specifically, the method for manufacturing a flexible electronic device of the present invention is, for example,
(i) A step of forming the first conductive wiring layer by printing a first conductive ink containing the first conductive material for forming the easily peelable conductive wiring layer on the base material.
(ii) Printing is performed using a second conductive ink containing a second conductive material for forming a non-peelable conductive wiring layer on the base material and the first conductive wiring layer. As a result, the step of forming the laminated conductive wiring layer in which the second conductive wiring layer is laminated on the first conductive wiring layer, and
(iii) A step of coating the laminated conductive wiring layer with a polymer thin film
(iv) The laminated conductive wiring layer coated with the polymer thin film is peeled off from the first conductive wiring layer or in the first conductive wiring layer, and is laminated on the film surface of the polymer thin film. It is a manufacturing method including a step of transferring a conductive wiring layer and forming a conductive wiring, and the flexible electronic device of the present invention can be manufactured by the manufacturing method.

As described above, the flexible electronic device of the present invention includes a laminated conductive wiring layer formed by peeling from or within the first conductive wiring layer that is easy to peel off. In this peeling step, the easily peelable conductive wiring layer has a multi-layer structure or an aggregated structure in which particles of the conductive wiring material are aggregated, and each layer forms a multi-layered or aggregated or aggregated structure with a gentle bonding force. When a physically strong force is applied in the direction of separating the upper and lower surfaces of the multilayer or laminated structure having an aggregated or aggregated structure, the multilayer or aggregated or aggregated structure cannot be maintained and the laminated or aggregated or aggregated layer cannot be maintained. It can be peeled off and separated inside.

Further, the flexible electronic device may further have an insulating protective layer that coats the laminated conductive wiring layer on the polymer thin film.

Therefore, as an example of the flexible electronic device of the present invention,
(i) A step of forming the first conductive wiring layer by printing a first conductive ink containing the first conductive material for forming the easily peelable conductive wiring on the base material.
(ii) Printing with a second conductive ink containing a second conductive material for forming a non-peelable conductive wiring on the base material and the first conductive wiring layer. To form a laminated conductive wiring layer in which a second conductive wiring layer is laminated on the first conductive wiring layer.
(iii) A step of coating the laminated conductive wiring layer with a polymer thin film
(iv) The laminated conductive wiring layer coated with the polymer thin film is peeled off from the first conductive wiring layer or in the first conductive wiring layer, and is laminated on the film surface of the polymer thin film. The process of transferring the conductive wiring layer to form the conductive wiring,
Examples thereof include flexible electronic devices manufactured by a method for manufacturing flexible electronic devices including.

In the flexible electronic device of the present invention
The step (iv) in the manufacturing method is
(iv') The step of coating the polymer thin film with a water-soluble support film and
(v') The laminated conductive wiring layer coated with the polymer thin film and the water-soluble support film is placed between the first conductive organic material layer and the base material or the first conductive organic material layer. A transfer step of transferring the laminated conductive wiring layer to the film surface of the polymer thin film by peeling it inside.
(vi') The structure of the polymer thin film, the water-soluble support film, and the laminated conductive wiring layer may be immersed in water to dissolve and remove the water-soluble support film.

Further, the flexible electronic device can also be used by coating the insulating protective layer that coats the laminated conductive wiring layer on the polymer thin film.

In the flexible electronic device of the present invention, for example, the conductive organic material used for the easily peelable conductive wiring layer or the first conductive wiring layer can be selected from a conductive carbon material and a conductive polymer.

Examples of the conductive carbon material include a material selected from one or more selected from conductive carbon black, carbon nanotubes, carbon nanotube derivatives, graphene, graphite, and conductive carbon fibers. Among these, carbon black, carbon nanotubes, graphene and the like are particularly preferable. For example, commercially available graphene flakes can be used. In addition, an inkjet ink in which graphene flakes are dispersed in a solvent is commercially available, and this can be obtained and used.

Examples of the conductive polymer include polythiophenes, polypyrroles, polyanilines, polyazulenes, polyindoles, polycarbazoles, polyacetylenes, polyfurans, polyparaphenylene vinylenes, polyazulenes, polyparaphenylenes, and polyparas. Examples include chain conductive polymers selected from phenylene sulfides, polyisothianaftens or polythiazyl. In particular, polythiophenes and polyanilines are preferable, and polyethylenedioxythiophene is more preferable, from the viewpoints of conductivity, transparency, stability and the like.

In particular, as a printing ink composition containing the conductive polymer, in order to achieve both conductivity and transmittance, a water-dispersible conductive polymer such as 3,4-polyethylenedioxythiophene polysulfonate (PEDOT: PSS) is used. The composition containing the binder resin is most preferable.

As described above, the laminated conductive wiring layer is a laminated conductive wiring layer formed by peeling off the easily peelable conductive wiring layer formed by the first conductive ink.
(A) Ease of peeling The conductive wiring layer can be peeled off by a multi-layer structure, or
(B) Ease of peeling The conductive wiring layer is formed by peeling due to a structure in which particles are aggregated or aggregated.

In the flexible electronic device of the present invention, graphene is preferable as an example of the conductive organic material (a) in which the easily peelable conductive wiring layer is formed from the multilayer structure.

For example, when printing on a base material using an ink containing graphene flakes as conductive material particles to form a conductive wiring layer, it is possible to form a conductive wiring layer in which graphene flakes are laminated in multiple layers. When a physical force is applied in the direction of separating the upper and lower surfaces of the conductive wiring layer, the multi-layer structure cannot be maintained and the conductive wiring layer is separated and separated in the graphene flake layer. At this time, each layer in the stack functions as a conductive wiring by forming a conductive wiring layer.

Further, the flexible electronic device of the present invention is a laminated layer in which a peelable conductive wiring layer is laminated on a non-peelable conductive wiring layer. A polymer thin film is laminated on a conductive wiring formed by a conductive wiring layer. It may be an electronic device having a body.

Therefore, the flexible electronic device of the present invention comprises the conductive organic material layer which is the easily peelable conductive material / the metal nanoparticle layer / the polymer thin film layer / the water-soluble support film which is the non-peeling conductive material layer. The laminate or the laminate of the metal nanoparticle layer which is the first conductive material / the conductive organic material layer / the polymer thin film layer / the water-soluble support film which is the second conductive material layer is placed in water. Conductive wiring formed by a laminated conductive wiring layer which is a laminate of a metal nanoparticle layer and a conductive organic material layer pattern-lined on a polymer thin film, which can be obtained by immersing and dissolving a water-soluble support film. It may be an electronic device having.

Utilizing the characteristics of the laminated conductive wiring layers, a light emitting or light source element can be applied to either a conductive wiring layer formed of a conductive organic material or a conductive wiring layer formed of metal nanoparticles. , Heat generating elements, integrated circuits, and other elements can be electrically connected. That is, this means that by connecting to the conductive wiring layer formed from the metal nanoparticles, the element can be connected to the conductive wiring layer before the conductive wiring layer is peeled off from the base material, which is also formed from the conductive organic material. By connecting the element to the conductive wiring layer to be formed, it is also possible to connect the element to the conductive wiring layer after peeling the conductive wiring layer from the base material, and it is a step of electrically connecting the element to the conductive wiring layer. It is possible to choose a different order.

For example, graphene flakes are used as the conductive material for forming the easily peelable conductive wiring layer of the flexible electronic device of the present invention, and metal nanoparticles are used as the conductive material for forming the non-peeling conductive wiring layer. By utilizing the layered structure of graphene flakes in the easily peelable conductive wiring layer, a laminated conductive wiring formed from graphene and gold nanoparticles by a polymer thin film and a water-soluble support film (polyvinyl alcohol). The layer can be peeled off from the substrate.

At this time, since the type of the base material is not limited, the above high temperature process for lowering the wiring resistance value can be applied by selecting a heat resistant base material such as glass as the base material.

In the flexible electronic device of the present invention, as an example of the (b) easily peelable conductive wiring layer, PEDOT: PSS is preferable as a conductive organic material formed from a structure in which particles are aggregated or aggregated.

Further, in the case of a conductive wiring layer in which a dispersion liquid of PEDOT: PSS (3,4-polyethylenedioxythiophene polysulfonate) is printed as a conductive ink on a substrate to form a conductive wiring layer, PEDOT and PSS are monomers. It forms the primary structure of the sequence and forms a polyion complex by electrostatic interaction. This is water-dispersed as colloidal particles, and when this dispersion is used, thin films or films can be formed as solids in which the colloidal particles are aggregated and laminated (Hidenori Okuzaki, Surface Science 32, 653-658, 2011). When the thin film or film formed by PEDOT: PSS is formed on, for example, a glass substrate and then peeled off, PEDOT: PSS can be peeled off without remaining on the glass substrate. Therefore, when the glass substrate is pattern-lined by printing or the like and then peeled off, it functions as a conductive wiring layer, and for example, a laminated conductive wiring layer can be formed by laminating with a conductive wiring layer composed of a metal nanoparticle layer. The conductive wiring layer may contain components other than metal nanoparticles, such as a paste material.

Further, when a conductive wiring layer composed of a laminate of conductive polymers is formed by printing and coating the same or different types of conductive polymers on a substrate multiple times, the conductive polymer can be used. If the bonding force between the layers that bond the monolayers is not necessarily strong, it is possible to maintain the bond between the monolayers by applying a physically strong force in the direction of pulling the upper and lower ends of the laminate apart. Instead, it is separated and peeled off between the laminated bodies of the conductive polymer. At this time, each layer functions as a conductive layer.

In the present specification, the "metal nanoparticles" used as the conductive material for forming the non-peelable conductive wiring layer refer to metal particles having a diameter of less than 1000 nm, preferably having a diameter of several tens of nm to. It is 300 nm.

In the present specification, "ink" is used synonymously with "ink", and a conductive material such as a conductive organic material or metal nanoparticles used in the present invention is dispersed in a liquid. A dispersion liquid for printing, which may contain a conductive paste used for printing conductive materials in the field of printed electronics.

Examples of the metal nanoparticles include gold, platinum, silver, copper, nickel, rhodium, palladium, magnesium, chromium, titanium, iron, and oxides thereof, and alloys of these metals and / or oxides thereof. Can be selected from nanoparticles such as. One type of metal nanoparticles may be used alone, or two or more types may be mixed and used. In particular, metal nanoparticle ink products for printing containing gold nanoparticle colloids are commercially available and can be obtained and used.

Further, for forming the non-peelable conductive wiring layer by laminating it on the first conductive wiring layer formed by printing with the first conductive ink for forming the easily peelable conductive wiring layer. In the formation of the laminated conductive wiring layer in which the first conductive material and the second conductive material are laminated, which is formed by printing with the second conductive ink, the first conductive material is the second conductive material. It is preferable that the conductive ink containing the material has a function as an ink receiving layer. However, it is not limited to this.

Examples of the base material include a glass base material and a polymer film base material. In particular, when a conductive wiring layer having a low electrical resistivity is obtained, a glass base material capable of heat treatment is preferable.

The polymer film base material used as the base material in the present invention is not particularly limited as long as it is a film formed from an organic polymer compound, for example, a polyolefin such as polyethylene or polypropylene, or a polyester such as polyethylene terephthalate or polyethylene naphthalate. , Polypropylene, Polypropylene, Polystyrene, Polyvinyl Alcohol, Ken's product of ethylene vinyl acetate copolymer, Polyacrylonitrile, Polyacetal, and other films formed from various polymers can be used. Among these, a film formed from polyethylene terephthalate is preferable.

The water-soluble support film is not limited to the polyvinyl alcohol, and is, for example, one or more water-soluble substances selected from the group consisting of the polyvinyl alcohol, gelatin, agarose, hyaluronic acid, alginic acid, sugar, salt, and polymer electrolyte. It is preferably a sex compound.

The insulating protective layer has not only a function of protecting the conductive wiring layer from physical or mechanical obstacles and avoiding disconnection or breakage, but also a function as an insulating layer. Examples of the material of the insulating protective layer include fluoropolymer compounds, polyethylene, polypropylene (PP), polyisobutylene, polyethylene terephthalate (PET), polyimide (PI), parylene, SU-8, polymethylmethacrylate (PMMA), Unsaturated polyester, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polyvinyl alcohol, polyvinyl acetal, acrylic resin, polyacrylonitrile, polystyrene (PS), acetal resin, polycarbonate, polyamide, phenol resin, urea resin, epoxy resin, melamine At least one selected from the group consisting of resins, styrene / acrylonitrile copolymers, acrylonitrile / butadiene styrene copolymers, silicones and polyphenylene oxides and polysulfones can be mentioned.

Further, it is preferable that the flexible electronic device of the present invention is injected into the living body from the outside of the living body using a syringe or the like in a bent state, and after the injection into the living body, the flexible electronic device exhibits a function as an electronic device in a spread state. .. That is, it is preferable that the needle can be bent into a substantially cylindrical shape having a diameter smaller than the inner diameter of the injection needle used for injection.

Therefore, in the flexible device of the present invention, the ratio of the maximum width in the bent direction when expanded so as to maximize the area of the conductive wiring layer and the maximum width in the bent direction when bent (width when expanded). A flexible device having a width) of 5 or more, preferably 10 or more, and more preferably 20 or more is preferable. Needle needles with a diameter smaller than 12G (outer diameter 2.70 ± 0.03 mm, inner diameter: 2.40 ± 0.03 mm) are commercially available and are used clinically. Therefore, the maximum width in the bending direction when bent is preferably less than 2.4 mm. In the present invention, it is possible to manufacture a flexible device that passes through an injection tube having an inner diameter of 2.0 mm at the tip of the tube in a bent state.

Polymer thin films smaller than 1 μm can be manufactured according to the description in WO2017 / 073728 and WO2017 / 188214. The laminated conductive wiring layer can be manufactured to be less than 2 μm as shown in the following examples. Therefore, the flexible electronic device of the present invention can be manufactured with a total film thickness of the laminated conductive wiring layer and the polymer thin film of less than 3 μm. Therefore, the total film thickness of the laminated conductive wiring layer and the polymer thin film is less than 100 μm, preferably less than 30 μm, more preferably less than 3 μm, and most preferably less than 1.5 μm.

As the polymer thin film in the flexible electronic device of the present invention, for example, a polymer having high flexibility made of a polylactic acid (PLA) thin film, an elastomer such as silicone, etc. so that it can be injected into a living body in a bent state. A thin film is preferable, and the thickness of the polymer thin film is 10 nm or more and less than 50 μm, preferably 50 nm or more and less than 10 μm, and more preferably 100 nm or more and less than 1 μm.

Further, as the polymer thin film, a self-supporting thin film can be used. As used herein, "self-standing thin films" are defined as thin films that are stable, capable of maintaining their properties, and support themselves without the need for any support. A thin film that can be formed.

In the bendable flexible electronic device of the present invention, when the conductive wiring layer is a laminated conductive wiring layer, the conductive wiring layer is laminated on the base material, the conductive material layer and the support film are formed, and then the conductive wiring layer is peeled off from the base material. It has a conductive polymer layer such as a conductive carbon material or a conductive polymer, and has fine wiring (<50 μm) containing metal nanoparticles formed by using, for example, inkjet printing, on the conductive polymer layer. Further, as described above, a desired small resistance value can be obtained by performing a high temperature heat treatment in the manufacturing process. Then, by using a sacrificial film or a support film formed of a water-soluble polymer such as polyvinyl alcohol (PVA), physical resistance can be imparted as compared with the polymer thin film alone. Therefore, by using the sacrificial film or the support film in the manufacturing process, the printed wiring can be peeled off from the base material, and the printed wiring can be transferred to any base material that is difficult to heat-treat or print.

As the material of the water-soluble support membrane, the above-mentioned material can be used.

As described above, the flexible electronic device of the present invention has a laminate formed by the conductive polymer layer and the conductive wiring layer of metal nanoparticles on the polymer thin film. In the formation of this laminate, a first conductive material (graphene flakes, PEDOT: PSS) is printed in advance on the surface of the base material as an ink receiving layer, so that the second conductive material is selectively printed on the receiving layer. As a result, metallic nanoparticles can be accumulated. As a result, a conductive wiring having no structural and electrical defects can be obtained. The thin-film electronic device has flexibility to the extent that it can be bent, and by bending it, for example, it is sucked using an injection needle having a size of 12 G (inner diameter: 2.4 mm) and injected into a living body or the like. Can be injected into the living body without causing disconnection, and can be embedded in the living body with small invasiveness.

Therefore, the flexible electronic device of the present invention can be used, for example, as an electronic device for injection from outside the living body into the living body. At this time, since no surgery such as skin incision is required, the flexible electronic device of the present invention can be injected into a living body with minimal invasiveness.

In the flexible electronic device of the present invention, examples of the conductive wiring layer include coil-shaped conductive wiring, and preferably the conductive wiring forms an antenna coil. By using such an antenna coil, it is possible to supply electric power to the flexible electronic device of the present invention embedded in a living body by wireless power supply from outside the living body. Further, the LED lamp can be made to emit light in the living body by supplying power to a light emitting element such as an LED lamp connected to the flexible electronic device of the present invention in the living body. Then, by using an LED lamp that emits a specific excitation wavelength, a fluorescent substance distributed in the living body is excited, and fluorescence can be emitted from the fluorescent substance.

Further, the flexible device of the present invention can be used not only for application to a light emitting device but also for controlling the release of a sustained-release drug by using, for example, an element that radiates Joule heat. Further, it is possible to supply electric power to an in vivo implantable electric device such as a cardiac pacemaker. Further, by using an integrated circuit as an element, for example, a cardiac pacemaker can be controlled wirelessly.

Further, the flexible device of the present invention can be used as a device utilizing optogenetics by using LED elements having different wavelengths such as red, green or blue for the irradiation light of the light emitting element. Optogenetics is a technique in which a light-sensitive, light-activated protein is expressed in cells using a genetic technique, and its function is controlled by light. Its application has already been reported in nematodes, Drosophila, zebrafish, mice, rats and primates.

For example, as a light-sensitive protein, a technique of expressing a rhodopsin protein having a function as an ion channel (ChR2) in a cell and opening the ion channel by light irradiation has also been reported. Furthermore, a technique for changing the wavelength of light for activation by using a mutant rhodopsin protein (ChR2 / C128X (X is T, A or S) or ChR2 / D156A) is also known, and an ion channel is used. Irradiation with blue bals light causes, for example, depolarization of nerve cells, and then irradiation with green light or orange light around 550 nm closes ion channels to restore the membrane potential. Can be done (Andre Berndt, et al., Nat. Neurosci .: 2009, 12 (2); 229-34).

Therefore, if ChR-expressing muscle cells are cultured and proliferated, the cells are transplanted into a living body (eg, myocardium), a flexible device equipped with the light emitting element of the present invention is injected near the transplantation site, and light is emitted by wireless power supply. A bio-pacemaker driven by light can be created on the surface of this device.

Further, in the application of the flexible device having the light emitting element of the present invention combined with the transplantation of light-sensitive cells, an integrated circuit (IC chip) is also incorporated in the flexible device, and the information of the integrated circuit is rewritten by electromagnetic waves. Precise pacing control can also be expected.

Since the flexible device of the present invention provided with the conductive wiring layer as the antenna coil can supply power from outside the living body by wireless power supply, there is no concern that the battery of the in-vivo implantable electric device runs out, and Since it does not require surgical measures to replace the battery, it can be used as a minimally invasive electronic device for living organisms.

As described above, the flexible electronic device of the present invention can be used by connecting a light emitting element, an element that emits Joule heat, an integrated circuit, or the like. In this case, the flexible electronic device of the present invention is a drug sustained-release system, in which a film surface of the polymer thin film provided with the conductive wiring layer is connected to a pair of terminals arranged at both ends of the conductive wiring. Examples of flexible electronic devices include an element selected from a light source or an integrated circuit, and the conductive wiring and the outer surface of the element are coated with an insulating protective layer.

More specifically, on the film surface of the polymer thin film provided with the coil layer, a pair of terminals arranged at both ends of the conductive wiring and an element selected from a drug sustained-release system, a light source, or an integrated circuit. It can be a flexible electronic device including a jumper for electrically connecting the pair of terminals and an insulating portion for insulating the jumper and the conductive wiring.

When the flexible electronic device of the present invention is used for implanting in a living body or the like, the polymer thin film is preferably selected from biocompatible thin films, and more specifically, polycaprolactone. , Polystyrene isoprene styrene, polystyrene, polydimethylsiloxane, silicone, polymethacrylic acid, polylactic acid, polylactic acid glycolic acid copolymer, polyvinylacetate, chitosan, alginic acid, cellulose acetate, hyaluronic acid, gelatin, or collagen. A thin film of commercially available polymer compound selected from one or more can be selected.

Further, the material of the insulating protective layer may be a biocompatible material as in the case of the polymer thin film so that the flexible electronic device of the present invention can be embedded and used in a living body. Materials for the biocompatible insulating protective layer include fluoropolymer compounds, polystyrene (PS), polymethylmethacrylate (PMMA), polyethylene terephthalate (PET), polypropylene (PP), polyimide (PI), parylene, etc. A thin film of one or more polymer compounds selected from the group consisting of SU-8, styrene-based elastomers, silicones, lactic acid copolymers, and electrolyte polymers can be selected.

Therefore, as described above, as an example of the flexible electronic device of the present invention, it is composed of a polymer thin film and printed wiring, and is housed in a microtube (injection needle, catheter, endoscopic trocar) or container (capsule). It can then be made into a thin film structure with mechanical flexibility and conductivity that can be released.

Further, in the manufacturing process of the flexible electronic device of the present invention, the wiring peeled from the base material is transferred to a polymer thin film prepared separately, and this is further coated with the same or different types of polymer thin films. It is possible to provide a thin film-like conductor that can be stored in an injection needle, a catheter, a capsule or the like according to the thickness of the polymer thin film and can be released without causing a large invasion to the living body.

Further, the flexible device of the present invention is not only used as the antenna coil described above, but also the fine conductive wiring peeled off from the base material is coated with an insulating polymer, and the tip thereof is a cutting tool such as scissors. The electrode portion can be easily exposed and can be used as an electrode by cutting with. At this time, by controlling the width and thickness of the wiring according to the print design, an impedance corresponding to the bioelectric potential of the measurement target can be obtained. Further, by repeating cutting, an electrode having the same impedance can be manufactured many times. Further, these electrodes can be used as probe electrodes.

Further, the flexible electronic device of the present invention can be used as a flexible electronic device that can be used as a power receiving device and / or a power transmitting device of a wireless power feeding system as described above.

Then, by using the flexible device of the present invention, it is possible to implant an electronic device inside a living body in a minimally invasive manner, so that a sensor, a light source, or a device for sustained release of a drug can be installed inside the living body. Become. Applications of the device include neural engineering, optogenetics and drug delivery systems (see Figures 4A and 4B).

2. 2. Method for Manufacturing Flexible Electronic Device Another embodiment of the present invention is the method for manufacturing the bendable flexible electronic device.

The method for manufacturing a flexible electronic device of the present invention
(i) A first conductive wiring layer is formed by printing a first conductive ink containing a first conductive material for forming a peelable conductive wiring layer on a base material. Conductive wiring layer forming process and
(ii) Printing is performed using a second conductive ink containing a second conductive material for forming a non-peelable conductive wiring layer on the base material and the first conductive wiring layer. As a result, the step of forming the laminated conductive wiring layer in which the second conductive wiring layer is laminated, and
(iii) A step of coating the laminated conductive wiring layer with a polymer thin film
(iv) The conductive wiring layer coated with the polymer thin film is peeled off from the conductive organic material layer or in the conductive organic material layer, and the laminated conductive wiring layer is formed on the film surface of the polymer thin film. It is a manufacturing method including a step of transferring the above and forming a conductive wiring.

Further, in the method for manufacturing the flexible electronic device of the present invention,
The step (iv) is
(iv') The step of coating the polymer thin film with a water-soluble support film and
(v') The laminated conductive wiring layer coated with the polymer thin film and the water-soluble support film is placed between the first conductive organic material layer and the base material or the first conductive organic material layer. A transfer step of forming the conductive wiring by transferring the laminated conductive wiring layer to the film surface of the polymer thin film by peeling it inside.
(vi') A manufacturing method including a step of immersing the structure of the polymer thin film, the water-soluble support film, and the laminated conductive wiring layer in water to dissolve and remove the water-soluble support film. You may.

In the method for manufacturing a flexible electronic device of the present invention, after the step (vi'), further
(vii') An insulating protective layer is coated on the transfer surface of the laminated conductive wiring layer to which the laminated conductive wiring layer of the polymer thin film is transferred and / or the film surface of the polymer thin film opposite to the laminated conductive wiring layer. The manufacturing method may include a step of forming an insulating protective layer for sealing.

Therefore, the method for manufacturing a flexible electronic device of the present invention includes a step of forming a conductive wiring layer in which conductive wiring is formed on a base material via a conductive organic material layer, and a conductive wiring layer of the laminate is coated with a polymer thin film. Further, a support film formed from the water-soluble support film is coated, and the conductive wiring layer coated with the polymer thin film and the water-soluble support film is formed from the conductive organic material layer or the conductive organic material layer. The transfer step of transferring the conductive wiring layer to the film surface of the polymer thin film by peeling it inside, and the lamination of the conductive wiring layer transferred on the laminated film of the water-soluble support film and the polymer thin film. The step of immersing the body in water to dissolve the water-soluble support film, and the laminated conductive wiring layer transfer surface to which the laminated conductive wiring layer of the polymer thin film is transferred and / or the laminated conductive wiring layer of the polymer thin film. The manufacturing method may include an insulating protective layer forming step of sealing by coating the film surface on the opposite side with the insulating protective layer.

In the manufacturing process of the flexible device of the present invention, the conductive material is made into an ink for printing by using an additive such as a surfactant, a dispersant, a moisturizing agent or an adhesion enhancer, and then printed by, for example, an inkjet method. It can be manufactured by pattern lining on a substrate (see FIG. 1: Schematic diagram when printing an antenna coil). Alternatively, the metal nanoparticle ink can be used to form the second conductive wiring layer.

The printing method at this time is not limited to the inkjet method, and examples thereof include flexographic printing, gravure printing, screen printing, pad printing, and lithography method. By laminating the first conductive material made of the conductive material and the metal nanoparticles which are the second conductive materials, it is possible to obtain a conductive wiring without defects which is likely to occur when the metal nanoparticles are individually pattern-lined. Be done.

Next, with respect to the laminated structure in which the first conductive material and the second conductive material are pattern-lined on the base material, if desired, a component contained as an additive in the printing ink is added. Heat treatment is performed to decompose or volatilize. The heating temperature is preferably 80 ° C. or higher, for example, when a glass base material is used as the base material and graphene flakes are used as the conductive material, the heating temperature is 80 ° C. or higher and 450 ° C. or lower, preferably 200 ° C. or higher and 450 ° C. or lower. The heat treatment step can be carried out preferably at 250 ° C. or higher and 400 ° C. or lower.

The materials such as the base material, the conductive organic material, the metal nanoparticles, the polymer thin film, the water-soluble support film, and the insulating protective layer used in the production method of the present invention are the same materials as those in "1. Flexible electronic device". Can be used.

In particular, as the conductive organic material, at least one selected from the group consisting of graphene flakes, PEDOT: PSS, fullerenes, carbon nanotubes, carbon nanofibers, polyaniline, polyparaphenylene, polyaniline, polythiophene, polyparaphenylene vinylene and polyacetylene. Can include a step of forming a conductive organic material layer using the above. In particular, for PEDOT: PSS, kits of various compositions are commercially available, and these can be obtained and used.

The method for manufacturing the flexible electronic device of the present invention will be described in more detail. It is formed of a conductive carbon material or a conductive polymer printed on a substrate obtained by the above step, or a conductive ink containing metal nanoparticles. A laminated conductive wiring layer in which a first conductive wiring layer and a conductive wiring layer formed of a second conductive ink containing a conductive carbon material or a conductive polymer are laminated. A polymer thin film such as polylactic acid or silicone is coated, and a water-soluble support film such as polyvinyl alcohol is further coated thereto (see FIG. 2). Then, the laminate of the first conductive material layer / metal nanoparticle layer / polymer thin film layer / support film is peeled off from the base material. At this time, when the graphene flakes are used as the first conductive material, the graphene flake layer is divided between the layers, so that the graphene remains on both the metal nanoparticle layer and the substrate.

Utilizing this characteristic, a light emitting or light source element, a heat generating element, and an integrated circuit can be applied to either a conductive wiring layer formed of a conductive organic material or a conductive wiring layer formed of metal nanoparticles. Etc. can be electrically connected. That is, this means that by connecting to the conductive wiring layer formed from the metal nanoparticles, the element can be connected to the conductive wiring layer before the conductive wiring layer is peeled off from the base material, which is also formed from the conductive organic material. By connecting the element to the conductive wiring layer to be formed, it is also possible to connect the element to the conductive wiring layer after peeling the conductive wiring layer from the base material, and it is a step of electrically connecting the element to the conductive wiring layer. It is possible to choose a different order.

Next, the laminate of the conductive organic material layer which is the first conductive material / the metal nanoparticle layer / the polymer thin film layer / the water-soluble support film which is the second conductive material layer, or the first. The metal nanoparticle layer which is the conductive material of the above, the conductive organic material layer which is the second conductive material layer, the polymer thin film layer, and the laminate of the water-soluble support film are immersed in water to dissolve the water-soluble support film. By doing so, it is possible to obtain a laminated conductive wiring layer which is a laminate of a metal nanoparticle layer and a conductive organic material layer pattern-lined on a polymer thin film. At this time, an element such as a light source can be appropriately connected to the terminal of the pattern line before the water-soluble support film is dissolved. Further, after the water-soluble support film is dissolved, the element can be appropriately connected to the terminal of the conductive wiring with pattern lining. Further, the flexible material of the present invention is made by forming a structure in which an electronic element is connected to a pattern-lined conductive material and metal nanoparticles produced in these steps and coating a protective layer having electrical insulation. Electronic devices can be manufactured.

As coating methods for these polymer thin films and support films, spin coating method, dipping method, spray coating method, electric field polymerization method, thin film deposition method, vapor deposition polymerization method, brush coating method, blade coating method, roller coating method and roll. -A known method such as a two-roll method can be used.

The insulating protective layer can be coated with the conductive wiring layer by using a known coating method, similarly to the polymer thin film and the support film. Examples of the coating method for coating the insulating protective layer include a spin coating method, a dipping method, a spray coating method, an electric field polymerization method, a vapor deposition method, a vapor deposition polymerization method, a brush coating method, a blade coating method, a roller coating method, or a roll coating method. A known method such as a two-roll method can be used.

In the manufacturing method of the present invention, examples of the conductive wiring layer include a coil or an electrode. When the conductive wiring layer is a coil, it is preferably an antenna coil.

As described in detail in the embodiment of "1. Flexible electronic device" above, the bendable flexible electronic device manufactured by the above manufacturing method is injected in vivo from the outside of the living body in a minimally invasive manner. For example, an electronic device for wireless power supply, light emission by a light emitting element, Joule heat generation by a Joule heat generating element, or an integrated circuit as an element, for example, a cardiac pacemaker embedded in a living body can be controlled. It can be used as a device for information communication.

Further, the flexible electronic device manufactured by the manufacturing method of the present invention can be carried out according to the embodiment used in the above-mentioned "1. Flexible electronic device".

All references referred to herein are incorporated herein by reference in their entirety. The examples described herein illustrate embodiments of the invention and should not be construed as limiting the scope of the invention.

Experimental method and results After heat-treating (250 ° C, 40 minutes) graphene (793663, Sigma Aldrich, USA) printed on a glass substrate with an inkjet printer (DMP-2831, FUJIFILM Corporation, Tokyo), gold. By overprinting nano ink (Au-JB 4010B, C-Ink Co., Ltd., Okayama Prefecture) and heat-treating (250 ° C, 20 minutes), a low-resistance antenna coil (thickness 1.47 μm, wiring width 400 μm, total length 29.6) cm, spiral 5.5 rolls) and pad (1 cm square) were prepared (Fig. 1).

A polymer solution (polylactic acid, polycaprolactone, solvent: ethyl acetate, polyvinyl alcohol, solvent: water) is dropped onto this antenna coil to prepare a polymer support film, which is subjected to high temperature treatment and has low resistance. The printed wiring was peeled off (Fig. 2).

From the cross-sectional profiles of the laminated conductive wiring layer before and after peeling, it was confirmed that the layer was peeled in the graphene layer. (Fig. 3). Before the peeling operation, the thickness of the laminated conductive wiring layer in which the gold nanoparticle layer and the graphene layer are laminated on the glass substrate is about 0.6 to about 1.8 μm, and the thickness of the graphene layer is about 0.4 to about 0.4. It was about 0.6 μm. After the peeling operation, the thickness of the graphene layer remaining on the substrate was about 0.1 to about 0.3 μm.

Polymer thin films can be manufactured with a film thickness of several tens of nanometers (International Pamphlets WO2017 / 073728 and WO2017 / 188214). Therefore, the layer thickness of the laminated conductive wiring layer and the polymer thin film layer can be produced as a laminated body of less than 1.5 μm.

The flexible electronic device of the present invention can be applied in the medical field for sustained drug release and LED emission (Fig. 4A), and for cardiac pacing in combination with transplantation of photosensitive cells by optogenetics (Fig. 4B). Is.

In addition, from Raman spectrum measurement, a spectrum derived from graphene was detected from both the coil on the peeled support film side and the wiring placed on the glass substrate. That is, it was shown that the printed wiring was detached from the base material starting from the peeling of the graphene layer in the graphite in which the graphene layer, which is a single-layer film, was laminated, which was used as the conductive organic material (FIG. 5).

This result is a conductive wiring layer in which conductive wiring layers used as conductive wiring are laminated, and for both the front and back surfaces of the conductive wiring layer, a light emitting element such as an LED, a heat generating element, an integrated circuit, a circuit, etc. It means that the elements of can be electrically connected. That is, it means that the element can be electrically connected to the conductive wiring at any stage after the heat treatment, before the conductive wiring is peeled off, or after the peeling, and the conductive wiring and the element are connected. Convenience is improved by increasing the timely options of the process.

The resistance value of the wiring after peeling was 145Ω, which was the same as that before peeling (131Ω). The resistivity at this time was 5.6 x 10 ^-7 Ω · m.

When the frequency characteristics of the wirelessly fed thin-film light emitting device manufactured by mounting the LED on the peeled printed wiring were measured with a network analyzer, it was shown to have a resonance frequency at 37 MHz (Fig. 6).

In addition, the LED of the device was lit by wireless power supply when the power supply frequency was 30 MHz, the voltage difference was 20 Vp-p, and the power was double amplified (FIGS. 7A and 7B). Further, even when stored in a gelatin capsule, it was lit under the same conditions (frequency 30 MHz, voltage difference 20 Vp-p, power double amplification) (FIG. 7C).

In addition, the flexible electronic device can be injected into water through a syringe syringe (inner diameter: 2 mm) (Fig. 8). The ratio of the length of one side when the flexible electronic device was unfolded to the width of the same side when it was bent was about 10.

In fact, using a flexible electronic device equipped with an LED coated on both sides of the flexible electronic device with an insulating protective layer (silicone rubber, thickness: 50 μm) that has been plasma-treated, in a phosphate buffer solution (PBS, pH 7.4). When immersed and wirelessly fed to a flexible electronic device from the outside with a power transmission antenna (voltage difference: 20Vp-p, frequency: 30MHz, when power is double amplified), the LED emits light in the phosphate buffer solution and operates normally. It was confirmed that (Fig. 9).

Application to optogenetics Next, we express photoresponsive channel protein (ChR2) and green fluorescent protein (Venus) for the purpose of application to optogenetics that reproduce various physiological phenomena by photostimulation. The presence of ChR2 was confirmed by irradiating the mouse skeletal myoblasts (C2C12) with blue light and observing the fluorescence of the green fluorescent protein (Venus).

Experimental materials The device used in the experiment consists of a laminated wiring layer in which graphene and gold nanoparticles are laminated on a polylactic acid thin film and printed in a coil shape in the same manner as above. An LED is electrically connected as a light emitting element to a polymer thin film. I used the one that I did.
The cells were mouse skeletal myoblasts (C2C12; RIKEN Cell Bank (RCB4693); Asano T. et al., Biotechnology and Bioengineering, 2012) expressing photoresponsive channel protein (ChR2) and green fluorescent protein (Venus). , 109, 199-204) was used. As the fluorescence microscope, KEYENCE BZ-X 710 type was used.

Experimental method Using the following method, mouse skeletal myoblasts (C2C12) expressing photoresponsive channel protein (ChR2) and green fluorescent protein (Venus) are irradiated with blue light to fluoresce the green fluorescent protein (Venus). The presence of ChR2 was confirmed by observing.
(1) ChR2-Venus C2C12 subcultured for 12 generations was cultured in a culture dish having a diameter of 60 mm for 4 days to a state of 100% confluet.
(2) ChR2-Venus C2C12 was irradiated with blue light emitted from the LED of this device by wireless power supply.
(3) The presence of ChR2 was confirmed by observing the green fluorescence of Venus excited by blue light.

Experimental Results Fig. 10 shows the results of observing green fluorescence by exciting Venus expressed in cells with blue light supplied by wireless power supply of this device.

With this device, we excited the green fluorescent protein expressed in cells and confirmed the expression of photoresponsive channel proteins. Based on this result, arbitrary photoresponsive cells (eg, channelrhodopsin (ChR)) were artificially expressed in vivo by applying this device, which can be implanted in vivo in a minimally invasive manner, to optogenetics. It has been shown that it can control the function of muscles and nerve cells).

Furthermore, by culturing the ChR2-expressing muscle cells (C2C12) used this time on the surface of this device and transplanting them into a living body (eg, myocardium), it can be applied as a biopacemaker driven by light using wireless power supply.

Claims (20)

Polymer thin films with a film thickness of 10 nm or more and less than 50 μm, and
The non-peelable conductive wiring layer formed on the polymer thin film and the easily peelable conductive wiring layer formed on the non-easy peelable conductive wiring layer are physically easier to peel off than the non-easy peelable conductive wiring layer. Conductive wiring, including a laminated conductive wiring layer having a conductive wiring layer
Have,
A flexible electronic device characterized in that the total film thickness of the laminated conductive wiring layer and the polymer thin film is less than 100 μm. The flexible electronic device according to claim 1, wherein the easily peelable conductive wiring layer has a multi-layer structure, or has a structure in which particles are aggregated or aggregated. The flexible electronic device according to claim 1 or 2, wherein the peelable conductive wiring layer is graphene or PEDOT: PSS. The ratio of the maximum width in the bent direction when expanded so that the area of the conductive wiring layer is maximized and the maximum width in the bent direction when bent (width when expanded / width when bent) is 5. The flexible electronic device according to any one of claims 1 to 3, wherein the flexible electronic device is characterized by the above. The flexible electronic device according to any one of claims 1 to 4, wherein the flexible electronic device is a foldable electronic device. The flexible electronic device according to any one of claims 1 to 5, wherein the flexible electronic device further has an insulating protective layer that coats the laminated conductive wiring layer on the polymer thin film. The flexible electronic device according to any one of claims 1 to 6, wherein the electronic device is an electronic device for injection from outside the living body into the living body. The flexible electronic device according to any one of claims 1 to 7, wherein the laminated conductive wiring layer is characterized in that the conductive wiring forms an electronic circuit. The flexible electronic device according to claim 8, wherein the electronic circuit is characterized in that conductive wiring forms a coil or an electrode. The flexible electronic device according to claim 9, wherein the coil is an antenna coil. The flexible electronic device according to any one of claims 1 to 10, wherein the resistivity of the conductive wiring is 100 × 10 ^{-7 Ωm or less.} An element selected from a light source or an integrated circuit, which is electrically connected to a pair of terminals arranged at both ends of the conductive wiring on a film surface of the polymer thin film provided with the laminated conductive wiring layer, is provided. The flexible electronic device according to any one of claims 1 to 11, wherein the conductive wiring and the outer surface of the element are coated with an insulating protective layer. The flexible electronic device according to any one of claims 1 to 12, wherein the polymer thin film is a self-supporting polymer thin film. The flexible electronic device according to any one of claims 1 to 13, wherein the flexible electronic device is used as a power receiving device and / or a power transmitting device in a wireless power feeding system. A method for manufacturing flexible electronic devices.
(i) A step of forming the first conductive wiring layer by printing a first conductive ink containing the first material for forming the easily peelable conductive wiring layer on the base material.
(ii) Printing is performed using a second conductive ink containing a second conductive material for forming a non-peelable conductive wiring layer on the base material and the first conductive wiring layer. As a result, the step of forming the laminated conductive wiring layer in which the second conductive wiring layer is laminated on the first conductive wiring layer, and
(iii) A step of coating the laminated conductive wiring layer with a polymer thin film
(iv) The laminated conductive wiring layer coated with the polymer thin film is peeled off from the first conductive wiring layer or in the first conductive wiring layer, and is laminated on the film surface of the polymer thin film. A method for manufacturing a flexible electronic device, which comprises a step of transferring a conductive wiring layer and forming a conductive wiring. The manufacturing method according to claim 15.
Process (iv) is
(iv') The step of coating the polymer thin film with a water-soluble support film and
(v') The laminated conductive wiring layer coated with the polymer thin film and the water-soluble support film is peeled off from between the first conductive wiring layer and the base material or in the first conductive wiring layer. The transfer step of transferring the laminated conductive wiring layer to the film surface of the polymer thin film, and
(vi') It is characterized by including a step of immersing the structure composed of the polymer thin film, the water-soluble support film, and the laminated conductive wiring layer in water to dissolve and remove the water-soluble support film. Manufacturing method. The manufacturing method according to claim 16, wherein after the step (vi'),
(vii') An insulating protective layer is coated on the transfer surface of the laminated conductive wiring layer to which the laminated conductive wiring layer of the polymer thin film is transferred and / or the film surface of the polymer thin film opposite to the laminated conductive wiring layer. A manufacturing method comprising a step of sealing. In the production method according to any one of claims 15 to 17, the laminated conductive wiring layer is heat-treated at 80 ° C. or higher and 400 ° C. or lower after step (ii) and before step (iii). A manufacturing method comprising a process. The production method according to any one of claims 15 to 18, wherein the polymer thin film is a self-supporting polymer thin film. The manufacturing method according to any one of claims 15 to 19, wherein the conductive wiring is an antenna coil.

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