Autonomous mobility sensing device and method for manufacturing autonomous mobility sensing device

Abstract

An autonomous mobility sensing device (10) comprising: a solid substrate (11); a first layer (12) disposed on one surface (11a) of the solid substrate (11); and a second layer (14) that covers the one surface (11a) of the solid substrate (11) and the first layer (12) and is bonded to a region on the one surface (11a) of the solid substrate (11) via an adhesive layer (13), wherein the region excludes the first layer (12) and the peripheral edge thereof, the first layer (12) is a catalyst, the second layer (14) is a permeable film, a space (15) between the solid substrate (11) and the first layer (12), and the second layer (14) is a product storage layer, and the adhesive layer (13) has an adhesive interface (16) that bonds the solid substrate (11) and the second layer (14), and a non-adhesive interface (17) that does not bond the solid substrate (11) and the second layer 12(14).

Description

Autonomous mobile sensing device and method for manufacturing the same

[0001] The present invention relates to an autonomous mobile sensing device and a method for manufacturing an autonomous mobile sensing device.

[0002] Sensing systems that measure target substances contained in liquids can provide concentration information that can be used as a basis for judgment in various situations, such as diagnosing illnesses and detecting water pollution.

[0003] Known methods for measuring substances contained in a liquid include a method in which a portion of the liquid to be measured is collected and analyzed (see, for example, Non-Patent Document 1), and a method in which the entire liquid space is analyzed using fluorescent substances or electrodes (see, for example, Non-Patent Documents 2 and 3).

[0004] Rissin, DM et al. Nat Biotechnol 28, 595-599 (2010). Beyene, AG et al. Sci Adv 5, (2019). Tringides, CM et al. Nat Nanotechnol 16, 1019-1029 (2021).

[0005] However, when a fluorescent substance is used, there is a problem in that it is difficult to remove the fluorescent substance after measurement, and it is difficult to restore the liquid space to its original state.

[0006] Furthermore, in the method using electrodes, the positions of the electrodes are fixed, so many electrodes are required to obtain spatial information on the concentration of the target substance. Furthermore, this method requires wiring for information transmission, which involves a lot of intervention into the liquid space.

[0007] The present invention has been made in consideration of the above circumstances, and aims to provide an autonomous mobile sensing device that is easy to remove after measurement and that, by moving autonomously, is capable of spatially comprehensive concentration analysis despite its small volume, and a method for manufacturing the autonomous mobile sensing device.

[0008] One aspect of the present invention is an autonomous mobile sensing device comprising a permeable film, a catalyst disposed inside a space formed by the permeable film, and a product accumulation layer formed inside the space, wherein the permeable film is made of a material that is permeable to substances that react with the catalyst but is impermeable to products generated by the catalyst and the substance.

[0009] One aspect of the present invention is a method for manufacturing an autonomous mobile sensing device, comprising the steps of: providing a mask seal having an opening on one side of a solid substrate; applying a metal coating to an exposed portion of the one side of the solid substrate that is exposed in the opening, thereby forming a metal thin film on the exposed portion; removing the mask seal from the one side of the solid substrate; and adhering a permeable film, via an adhesive layer, to cover the one side of the solid substrate and the metal thin film and to an area of ​​the one side of the solid substrate excluding the metal thin film and its peripheral edge, wherein in the step of adhering the permeable film, the adhesive layer forms a layer having an adhesive interface that adheres the solid substrate to the permeable film, and a non-adhesive interface that does not adhere the solid substrate to the permeable film.

[0010] According to the present invention, it is possible to provide an autonomous mobile sensing device that is easy to remove after measurement and that, by moving autonomously, is capable of spatially comprehensive concentration analysis despite its small volume, as well as a method for manufacturing an autonomous mobile sensing device.

[0011] 1 is a schematic diagram of an autonomous mobile sensing device according to a first embodiment of the present invention, showing a cross-sectional view in the radial direction of the autonomous mobile sensing device; FIG. 2 is a schematic diagram of an autonomous mobile sensing device according to a second embodiment of the present invention, showing a cross-sectional view in the thickness direction of the autonomous mobile sensing device; FIG. 3 is a schematic diagram of an autonomous mobile sensing device according to a second embodiment of the present invention, showing a cross-sectional view in the thickness direction of the autonomous mobile sensing device; FIG. 4 is a schematic diagram of an autonomous mobile sensing device according to a first embodiment of the present invention, showing a cross-sectional view in the thickness direction of the autonomous mobile sensing device; FIG. 5 is a schematic diagram of an autonomous mobile sensing device according to a first embodiment of the present invention, showing a cross-sectional view in the thickness direction of the autonomous mobile sensing device; FIG. 6 is a schematic diagram of an autonomous mobile sensing device according to a first embodiment of the present invention, showing a cross-sectional view in the thickness direction of the autonomous mobile sensing device; 10A and 10B are photographs showing the function of the autonomous mobile device of the present invention in the examples.

[0012] The present invention will be described below based on preferred embodiments with reference to the drawings, but the present invention is not limited to these embodiments. Note that the drawings used in the following description may show essential parts enlarged for the sake of convenience in order to make the features of the present invention easier to understand, and the dimensional proportions of each component may not necessarily be the same as those in reality.

[0013] First Embodiment Fig. 1 is a schematic diagram of an autonomous mobile sensing device according to a first embodiment of the present invention, showing a radial cross-section of the autonomous mobile sensing device. As shown in Fig. 1, the autonomous mobile sensing device 1 of this embodiment includes a central portion 2, a first layer 3 surrounding the periphery of the central portion 2, and a second layer 4 surrounding the periphery of the first layer 3. The central portion 2 is a product accumulation layer. The first layer 3 is a catalyst. The second layer 4 is a permeable film. Hereinafter, the central portion 2 will be referred to as the product accumulation layer 2, the first layer 3 as the catalyst 3, and the second layer 4 as the permeable film 4.

[0014] "Product accumulation layer" The product accumulation layer 2 is a layer that accumulates products produced when a substance contained in the liquid that reacts with the catalyst (hereinafter referred to as "reactant") is decomposed by the catalyst. The product accumulation layer 2 is the internal space of the cylindrically formed permeable film 4, and more specifically, the central region of the internal space. The product accumulation layer 2 periodically deforms according to the amount of product produced.

[0015] "Catalyst" The catalyst 3 decomposes reactants contained in the liquid to generate products. Examples of catalysts 3 include metal catalysts such as platinum and palladium, oxide catalysts such as vanadium oxide and alumina (aluminum oxide), biocatalysts such as catalase and ribozymes, and artificial catalysts (nanozymes) based on nanomaterials. The catalyst 3 is retained inside the autonomous mobile sensing device 1 by interaction with the permeable film 4. The catalyst 3 can be immobilized by chemical bonding, sputtering, vapor deposition, or the like.

[0016] The catalyst 3 may be used alone or in combination of two or more. An appropriate catalyst is selected as the catalyst 3 so that, when the autonomous mobile sensing device 1 is immersed in liquid, it initiates a decomposition reaction of a reactant contained in the liquid and produces a final product that does not permeate the permeable film 4. When two or more types of catalysts 3 are used in combination, two or more types of catalysts may be mixed and attached to the internal space of the permeable film 4, or the catalysts may be separated by type and attached to the internal space of the permeable film 4, and then a flow path connecting the catalysts may be designed so that the products are exchanged in the order of the reaction.

[0017] Products produced by the decomposition reaction of reactants include gases and substances dissolved in the liquid. For example, in a catalytic reaction that synthesizes a protein from amino acids contained in a liquid, the produced protein is a substance dissolved in the liquid. In this case, by controlling the pore size (diameter) of the permeable film 4 so that the amino acids, which are reactants, can pass through but the produced protein cannot, large proteins can be accumulated in the product accumulation layer 2. Furthermore, by designing the autonomous mobile sensing device 1 so that a product release port opens in response to an external stimulus such as light, the protein accumulated in the product accumulation layer 2 can be released in response to the external stimulus. In other words, the autonomous mobile sensing device 1 can obtain a driving force through self-diffusiophoresis.

[0018] Autonomous movement can be controlled by using a catalyst whose reaction changes in response to an external stimulus in the autonomous mobile sensing device 1. As an example, titanium oxide, a photocatalyst, generates oxygen when irradiated with light, so by using titanium oxide as the catalyst in the autonomous mobile sensing device, the device will emit bubbles and move autonomously when irradiated with light, and will stop moving when not irradiated.

[0019] "Permeable Film" The permeable film 4 must be permeable to reactants contained in a liquid or gas (atmosphere) but not permeable to products produced from the reactants by the catalyst 3.

[0020] At least one selected from a hydrogel, an elastomer, and a porous film is preferably used as the permeable film 4. That is, as the permeable film 4, one selected from a hydrogel, an elastomer, and a porous film may be used alone, or two or more selected from the group consisting of a hydrogel, an elastomer, and a porous film may be used in combination.

[0021] Hydrogels can be made from synthetic polymers such as polyacrylamide and polyvinyl alcohol, or biopolymers such as gelatin and alginic acid. Other examples include copolymer gels combining acrylamide and aminophenylboronic acid, and interpenetrating network gels combining polyvinyl alcohol and polyaniline. Furthermore, functional gels incorporating gold nanoparticles or carbon nanotubes can also be used. The hydrogel may contain a fluorescent substance that responds to the analyte. The inclusion of a fluorescent substance in the hydrogel allows for analysis of the analyte concentration through fluorescence observation. Because the fluorescent substance is contained within the hydrogel, it is easily removed, allowing for restoration of the measurement space.

[0022] By adjusting the permeability of the hydrogel, it is possible to appropriately control the inflow of reactants from the outside into the autonomous mobile sensing device 1 and the accumulation of products inside the autonomous mobile sensing device 1. Methods for controlling the permeability of the hydrogel include a method of adjusting the chemical composition of the hydrogel and a method of adjusting the physical structure of the hydrogel.

[0023] Methods for adjusting the chemical composition of hydrogels include, for example, adjusting the properties of the materials used as the hydrogel, particularly the positive or negative charge, or adjusting the hydrophilicity or hydrophobicity. These methods can control the diffusion rate of reactants and products within the hydrogel. Examples of positively charged materials include poly(N-[3-(dimethylamino)propyl]acrylamide-methyl chloride quaternary salt) and chitosan. Examples of negatively charged materials include polyacrylic acid, polystyrene sulfonic acid, and hyaluronic acid. Examples of hydrophilic materials include polyacrylamide, poly(N-(2-hydroxyethyl)acrylamide), N,N-dimethylacrylamide, and collagen. Examples of hydrophobic materials include polystearyl acrylate, polyhexadecyl acrylate, and poly(tert-butyl acrylate).

[0024] Methods for adjusting the physical structure of a hydrogel include, for example, making the hydrogel porous. One method for making the hydrogel porous is to polymerize a monomer in a cosolvent of dimethyl sulfoxide and water. The resulting hydrogel has larger pore sizes than normal due to the co-poor solvent effect. Alternatively, a hydrogel can be synthesized by incorporating a soluble sacrificial material (metal particles, ice, silica particles, etc.) and then removing the sacrificial material from the resulting hydrogel to make the hydrogel porous. By controlling the pore size in this way, reactants smaller than the pore size are supplied from the liquid to the interior of the autonomous mobile sensing device 1, while reactants larger than the pore size are prevented from diffusing from the interior to the exterior of the autonomous mobile sensing device 1 and accumulate within the autonomous mobile sensing device 1.

[0025] Examples of the elastomer include styrene block copolymers, polyolefins, polyurethanes, and polydimethylsiloxanes.

[0026] Examples of porous films include polystyrene, mesoporous silica, zeolite, and metal organic frameworks.

[0027] The permeable film 4 can be formed into any shape using a mold, a sacrificial layer, or 3D printing technology. The autonomous mobile sensing device 1 does not use a solid substrate and is composed of the permeable film 4 and a catalyst 3. The autonomous mobile sensing device 1 can be formed by coating the surface of a spherical alginate gel with a catalyst, forming a permeable film on the outside, and then dissolving the alginate gel in an ethylenediaminetetraacetic acid solution to form an internal space, thereby forming a catalyst-containing film with the inner wall as a catalyst layer.

[0028] The use of a stimulus-responsive film makes it possible to control the amount of product released in response to a stimulus in the autonomous mobile sensing device 1. There are no particular limitations on the configuration of the stimulus-responsive film, but for example, a hydrogel made of a copolymer of acrylamide phenylboronic acid and acrylamide is a gel whose degree of swelling changes depending on the glucose concentration, and therefore, by making the flow path portion of the device out of this glucose-responsive gel, a device can be obtained in which the driving force changes depending on the glucose concentration.

[0029] The autonomous mobile sensing device 1 of this embodiment does not have a flow path for releasing the product (it does not have mobility), so it is possible to concentrate the product of a catalytic reaction in the liquid inside. This can be used as a reactor that uses the concentrated product to carry out a further chemical reaction in the liquid with high efficiency.

[0030] In the autonomous mobile sensing device 1 of this embodiment, the product accumulation layer 2 accumulates a product and periodically deforms in response to the amount of product produced. The concentration of a substance to be measured contained in a liquid can be analyzed from the deformation period of the product accumulation layer 2, which corresponds to the amount of product produced. For example, when hydrogen peroxide contained in a liquid is reacted to form oxygen bubbles within the autonomous mobile sensing device 1, the concentration of hydrogen peroxide can be calculated by optically observing the gel volume expansion when the bubbles accumulate and the volume contraction when the bubbles are released. Furthermore, in the autonomous mobile sensing device 1, the product accumulation layer 2 accumulates a product, and the movement amount of the autonomous mobile sensing device 1 in the liquid changes in response to the amount of product produced. The concentration of a substance to be measured contained in a liquid can be analyzed from the movement amount of the autonomous mobile sensing device 1, which corresponds to the amount of product produced. As a method for analyzing the concentration of the substance to be measured contained in the liquid from the amount of movement of the autonomous mobile sensing device 1, for example, when hydrogen peroxide contained in the liquid is reacted to form oxygen bubbles within the autonomous mobile sensing device 1, the frequency of bubble release varies depending on the concentration of hydrogen peroxide, so the hydrogen peroxide concentration can be calculated by measuring the amount of movement of the autonomous mobile sensing device 1 due to bubble release.

[0031] Second Embodiment FIG. 2 is a schematic diagram of an autonomous mobile sensing device according to a second embodiment of the present invention, illustrating a cross-sectional view of the autonomous mobile sensing device in the thickness direction. As shown in FIG. 2 , the autonomous mobile sensing device 10 of this embodiment includes a solid substrate 11, a first layer 12, an adhesive layer 13, a second layer 14, and a space 15. The first layer 12 is disposed on one surface 11a of the solid substrate 11. The adhesive layer 13 is provided on a region of the one surface 11a of the solid substrate 11 excluding the first layer 12 and its periphery. The second layer 14 covers the one surface 11a of the solid substrate 11 and the first layer 12, and is adhered to a region of the one surface 11a of the solid substrate 11 excluding the first layer 12 and its periphery via the adhesive layer 13. The space 15 is a space between the solid substrate 11, the first layer 12, and the second layer 14. The first layer 12 is a catalyst. The second layer 14 is a permeable film, and the space 15 is a product accumulation layer. Hereinafter, the first layer 12 is referred to as the catalyst 12, the second layer 14 is referred to as the permeable film 14, and the space 15 is referred to as the product accumulation layer 15.

[0032] The adhesive layer 13 has an adhesive interface 16 that bonds the solid substrate 11 and the second layer 12 together, and a non-adhesive interface 17 that does not bond the solid substrate 11 and the second layer 12 together. The non-adhesive interface 17 is a flow path-forming interface where the solid substrate 11 and the second layer 12 separate as the product accumulates in the product accumulation layer 15, thereby discharging the product from the product accumulation layer 15 to the outside. The non-adhesive interface 17 is also referred to as a flow path-forming interface 17.

[0033] "Solid substrate" Examples of the solid substrate 11 include oxide substrates such as glass and indium tin oxide, metal substrates such as gold and copper, and organic substrates such as polymer films and plastics. As the solid substrate 11, a composite substrate obtained by combining the oxide substrate, the metal substrate, and the organic substrate can also be used. As the composite substrate, for example, a substrate can be used in which metal wiring is formed on the surface of a glass substrate to form an electronic device and to provide wireless communication functions, etc.

[0034] When creating a space at the non-adhesive interface between the solid substrate 11 and the permeable film 14 in order to accumulate the product, by using a hydrogel as the permeable film 14 and using a solid substrate 11 with a significantly higher modulus of rigidity than the hydrogel, it is possible to induce a space due to the buckling and peeling phenomenon of the hydrogel.

[0035] One method for bonding the solid substrate 11 and the hydrogel is to form a chemical bond between the hydrogel and functional groups on the surface 11a of the solid substrate 11. Methacrylic groups can be exposed by reacting 3-(trimethoxysilyl)propyl methacrylate with hydroxyl groups on the surface 11a of the solid substrate 11. Because the methacryl group is a radical polymerization reactive group, the solid substrate 11 and the hydrogel can be bonded by radically polymerizing the hydrogel on the surface 11a of the solid substrate 11. Because the methacryl groups are removed by oxygen plasma, an adhesive interface can be formed at any desired location using lithography techniques.

[0036] The flow channel forming interface of the autonomous mobile sensing device 10 is formed in the same manner as the non-adhesive interface between the solid substrate 11 and the permeable film 14, but by designing the flow channel surface area to be smaller than that of the product accumulation layer 15, it becomes possible to accumulate the encapsulated product.

[0037] The shape of the solid substrate 11 and the shape of the non-adhesive interface between the solid substrate 11 and the permeable film 14 are not limited, and the non-adhesive interface between the solid substrate 11 and the permeable film 14 can also be coated with another material. For example, by coating the non-adhesive interface between the solid substrate 11 and the permeable film 14 with gelatin, the inside of the autonomous mobile sensing device 10 can be used as a cell culture substrate.

[0038] "Catalyst" The catalyst 12 is similar to the catalyst 3 described above. The catalyst 12 is retained inside the autonomous mobile sensing device 10 by interaction with the solid substrate 11 or the permeable film 14. As the catalyst 12, an appropriate catalyst is selected that produces a substance that does not permeate the solid substrate 11 or the permeable film 14 as the final product.

[0039] "Adhesive Layer" Methods for bonding the solid substrate 11 and the permeable film 14, i.e., methods for forming the adhesive layer 13, include chemical bonding by silane coupling or the like, mechanical bonding by processing the solid substrate into recesses and protrusions, and physical bonding by hydrophobic interaction or the like.

[0040] "Transparent Film" The transparent film 14 is similar to the transparent film 4 described above.

[0041] "Product Accumulation Layer" The product accumulation layer 15 is similar to the product accumulation layer 2 described above.

[0042] The operation of the autonomous mobile sensing device 10 will now be described. When the autonomous mobile sensing device 10 is placed in a reaction solution, as shown in FIG. 3 , reactants contained in the reaction solution permeate the permeable film 14, and a reaction occurs in which the reactants are decomposed by the catalyst 12, generating product 20. The product 20 accumulates in a space (product accumulation layer) 15 at the non-bonded interface between the solid substrate 11 and the permeable film 14. As shown in FIG. 4 , when the amount of product 20 accumulated in the space (product accumulation layer) 15 reaches a certain level, the product 20 is released from the inside to the outside of the autonomous mobile sensing device 10 through a flow path 18 at a non-bonded interface 17 (flow path forming interface 17) previously formed at a portion of the non-bonded interface between the solid substrate 11 and the permeable film 14. The force generated during the release allows the autonomous mobile sensing device 10 to move in the liquid. This catalytic reaction continues semi-permanently as long as reactants are present in the liquid, and the accumulation and release of product 20 continues, allowing the autonomous mobile sensing device 10 to continue moving in the liquid.

[0043] The autonomous mobile sensing device 10 of this embodiment is able to move freely in the length direction of the autonomous mobile sensing device 10 in the liquid due to the shape of the flow path 18. Furthermore, when the product 20 is a gas, the buoyancy of the accumulated bubbles also enables the autonomous mobile sensing device 10 to move in the thickness direction of the autonomous mobile sensing device 10. Therefore, the autonomous mobile sensing device 10 of this embodiment can be used as a detection device that analyzes the entire range of the liquid by autonomously moving three-dimensionally in the space under the liquid.

[0044] The autonomous mobile sensing device 10 of this embodiment is designed to control the opening and closing of the flow path 18 that releases the product 20 using external stimuli (light, heat, pH, chemicals, etc.), and can be used as a transport device that transports an encapsulated substance to any location in the liquid space and releases the encapsulated substance there when it receives an external stimuli.

[0045] The autonomous mobile sensing device 10 of this embodiment can transmit pressure to the outside by pulsating the permeable film 14, which is a swelling and contraction cycle, by releasing the product 20 at a high frequency. Therefore, the permeable film 14 is made only of artificial materials (without using cardiac muscle cells, etc.), and can contribute to medical research as a heart-mimicking device that operates in an environment that is less harmful to living organisms.

[0046] The autonomous mobile sensing device 10 of this embodiment is characterized by the accumulation of products by utilizing the hydrogel's permeability to reactants contained in the liquid and its impermeability to the produced gas, and by its release when a certain amount of product has accumulated.Therefore, the device can take many different forms, and does not require the internal energy source (battery, etc.) required for conventional liquid-movement devices, or the need for small device sizes that require low output energy.

[0047] The autonomous mobile sensing device 10 of this embodiment is characterized by the accumulation of products utilizing the hydrogel's permeability to reactants contained in the liquid and its impermeability to the produced gas, and its release when a certain amount of product has accumulated, and therefore many possible device configurations are possible. Furthermore, the autonomous mobile sensing device 10 of this embodiment does not require an internal energy source (such as a battery) or a small device size that requires low output energy, which were necessary for conventional devices that move in liquid.

[0048] In the autonomous mobile sensing device 10 of this embodiment, the product accumulation layer 15 accumulates a product and periodically deforms in response to the amount of product produced. The concentration of a substance to be measured contained in a liquid can be analyzed from the deformation period of the product accumulation layer 15 in response to the amount of product produced. Methods for analyzing the concentration of a substance to be measured contained in a liquid from the deformation period of the product accumulation layer 15 include, for example, observing gel volume changes with a conventional optical microscope, impregnating a hydrogel with a fluorescent substance and observing volume changes with a fluorescent microscope, and electrically measuring changes in capacitance due to volume changes. When hydrogen peroxide contained in a liquid reacts to form oxygen bubbles within the autonomous mobile sensing device 10, the concentration of hydrogen peroxide can be calculated by optically observing the gel volume expansion as the bubbles accumulate and the volume contraction as the bubbles are released. Furthermore, in the autonomous mobile sensing device 10, the product accumulation layer 15 accumulates a product, and the movement distance of the autonomous mobile sensing device 10 in the liquid changes in response to the amount of product produced. The concentration of the substance to be measured contained in the liquid can be analyzed from the amount of movement of the autonomous mobile sensing device 10, which corresponds to the amount of product produced. Methods for analyzing the concentration of the substance to be measured contained in the liquid from the amount of movement of the autonomous mobile sensing device 10 include, in addition to conventional optical observation, a method in which a marker substance such as a fluorescent substance or a conductive substance is contained in the device, and the trajectory of the marker substance is analyzed by fluorescent observation or electrical measurement to calculate the amount of movement. When hydrogen peroxide contained in the liquid is reacted to produce oxygen bubbles within the autonomous mobile sensing device 10, the frequency of bubble release varies depending on the concentration of hydrogen peroxide, and therefore the hydrogen peroxide concentration can be calculated by measuring the amount of movement of the autonomous mobile sensing device 10 due to bubble release.

[0049] [Method for manufacturing an autonomous mobile sensing device] A method for manufacturing an autonomous mobile sensing device according to one embodiment of the present invention comprises the steps of providing a mask seal having an opening on one surface of a solid substrate (hereinafter referred to as the "first step"), applying a metal coating to an exposed portion of one surface of the solid substrate that is exposed in the opening, and forming a metal thin film on the exposed portion (hereinafter referred to as the "second step"), removing the mask seal from one surface of the solid substrate (hereinafter referred to as the "third step"), and adhering a transparent film via an adhesive layer to cover one surface of the solid substrate and the metal thin film, and to an area of ​​the one surface of the solid substrate excluding the metal thin film and its peripheral edge (hereinafter referred to as the "fourth step").

[0050] 5 to 8 are cross-sectional views that schematically show a method for manufacturing an autonomous mobile sensing device according to one embodiment of the present invention.

[0051] In the method for manufacturing an autonomous mobile sensing device of this embodiment, first, methacryl groups are exposed on the surface of a solid substrate. Here, a method for obtaining a methacryl group-exposed glass substrate, in which methacryl groups are exposed on the surface of a glass substrate, is described. A glass substrate is immersed in an aqueous sodium hydroxide solution and washed to obtain a cleaned glass substrate. Next, the cleaned glass substrate is subjected to an oxygen plasma treatment to obtain a surface-activated glass substrate. Next, the surface-activated glass substrate is treated with a silane coupling solution containing 3-(trimethoxysilyl)propyl methacrylate to obtain a methacryl group-exposed glass substrate.

[0052] 5, in the first step, a mask seal 30 having an opening 31 is provided on one surface 11a of a solid substrate 11. The above-mentioned methacrylic group-exposed glass substrate is used as the solid substrate 11. A mask seal 30 having a cut line is attached to one surface 11a of the solid substrate (methacrylic group-exposed glass substrate) 11.

[0053] 6, in the second step, a metal coating is applied to the exposed portion 11A of the one surface 11a of the solid substrate 11, the exposed portion 11A being exposed in the opening 31 of the mask seal 30, to form a metal thin film 41 on the exposed portion 11A. For example, a sputtering method can be used to apply the metal coating. Examples of metals that can form the metal thin film 41 include metals such as platinum and palladium, and oxides such as vanadium oxide and alumina (aluminum oxide).

[0054] 7, in the third step, the mask seal 30 is removed from the surface 11a of the solid substrate 11. Specifically, the area surrounded by the cut lines is removed from the mask seal 30, and the methacrylic groups in the exposed areas are removed by oxygen plasma treatment. Thereafter, the remaining mask seal 30 is removed.

[0055] [Step 4] In step 4, the first surface 11a of the solid substrate 11 and the thin metal film 41 are covered, and a permeable film 14 is adhered to the first surface 11a of the solid substrate 11, excluding the thin metal film 41 and its periphery, via an adhesive layer 13. An example of a method for providing the permeable film 14 will be described. A gel precursor solution containing acrylamide as a monomer, bisacrylamide as a crosslinking agent, and lithium phenyl(2,4,6-trimethylbenzoyl)phosphinate as a polymerization initiator is prepared. Next, the gel precursor solution is dropped onto the first surface 11a of the solid substrate 11 and the thin metal film 41. Next, the gel precursor solution is irradiated with ultraviolet light to polymerize, forming a film-like gel permeable film 14 that covers the first surface 11a of the solid substrate 11 and the thin metal film 41, as shown in FIG. 8 .

[0056] In the fourth step, a layer having an adhesive interface 16 that bonds the solid substrate 11 and the permeable film 14 and a non-adhesive interface 17 that does not bond the solid substrate 11 and the permeable film 14 is formed as the adhesive layer 13. The method for forming the adhesive interface 16 is as described above. The method for forming the non-adhesive interface 17 is as described above.

[0057] The above steps result in the autonomous mobile sensing device 10. The metal thin film 41 serves as the catalyst 12.

[0058] According to the method for manufacturing the autonomous mobile sensing device of this embodiment, the autonomous mobile sensing device 10 of the above-described embodiment is obtained.

[0059] The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to the following examples.

[0060] [Example] As an example of an autonomous mobile device, we will explain a device that uses a glass substrate as the solid substrate, platinum as the catalyst, and acrylamide gel as the permeable film. This device produces oxygen from hydrogen peroxide in a solution through a platinum-catalyzed reaction, and moves forward by releasing bubbles composed of oxygen.

[0061] First, methacryl groups were exposed on the surface of a solid substrate. Here, a method for obtaining a methacryl group-exposed glass substrate, in which methacryl groups were exposed on the surface of a glass substrate, is described. A glass substrate was immersed in an aqueous sodium hydroxide solution and washed to obtain a washed glass substrate. Next, the washed glass substrate was subjected to oxygen plasma treatment to obtain a surface-activated glass substrate. Next, the surface-activated glass substrate was treated with a silane coupling solution containing 3-(trimethoxysilyl)propyl methacrylate to obtain a methacryl group-exposed glass substrate.

[0062] 5, a mask seal 30 having an opening 31 was provided on one surface 11a of a solid substrate 11. The above-mentioned methacrylic group-exposed glass substrate was used as the solid substrate 11. A mask seal 30 having a cut line was attached to one surface 11a of the solid substrate (methacrylic group-exposed glass substrate) 11.

[0063] As shown in FIG. 6, an exposed portion 11A of one surface 11a of the solid substrate 11, which is exposed in the opening 31 of the mask seal 30, was coated with platinum by sputtering to form a metal thin film 41 made of platinum.

[0064] 7, the area surrounded by the cut lines was removed from the mask seal 30 on the surface 11a of the solid substrate 11, and the methacryl groups in the exposed area were removed by oxygen plasma treatment. Thereafter, the remaining mask seal 30 was removed.

[0065] Next, a transparent film 14 was attached to the surface 11a of the solid substrate 11, covering the first surface 11a and the thin metal film 41, excluding the thin metal film 41 and its periphery, via an adhesive layer 13. A gel precursor solution containing acrylamide as a monomer, bisacrylamide as a crosslinker, and lithium phenyl(2,4,6-trimethylbenzoyl)phosphinate as a polymerization initiator was prepared. The gel precursor solution was then dropped onto the first surface 11a of the solid substrate 11 and the thin metal film 41. The gel precursor solution was polymerized by ultraviolet irradiation while diffusion was restricted by 80 μm-thick spacers on both ends of the solid substrate 11 and a cover glass on the top surface. As shown in FIG. 8, an 80 μm-thick film-like gel transparent film 14 was formed, covering the first surface 11a of the solid substrate 11 and the thin metal film 41. Through the above process, an autonomous mobile sensing device 10 was obtained.

[0066] When the obtained autonomous mobile sensing device 10 was placed in a hydrogen peroxide solution, air bubbles accumulated around the platinum metal thin film 41 over time, and after a certain amount of accumulation, the autonomous mobile sensing device 10 was observed moving when the air bubbles were released, as shown in Figure 9. Note that Figure 9 shows the state as time passed, progressing from Figure 9(a) to Figure 9(b) to Figure 9(c).

[0067] Furthermore, as shown in FIG. 10, the time required for the autonomous mobile sensing device 10 to release gas changed depending on the hydrogen peroxide concentration, demonstrating that the hydrogen peroxide concentration can be measured from the deformation period.

[0068] The autonomous mobile sensing device according to the present invention is useful for analyzing spatially comprehensive concentration information by taking advantage of its autonomous mobility, and is widely applicable to fields such as medical engineering, food engineering, and environmental engineering.

[0069] REFERENCE SIGNS LIST 1, 10 Autonomous mobile sensing device 2 Central portion (product accumulation layer) 3, 12 First layer (catalyst) 4, 14 Second layer (permeable film) 11 Solid substrate 11A Exposed portion 13 Adhesion layer 15 Space (product accumulation layer) 16 Adhesion interface 17 Non-adhesion interface 18 Flow path 20 Product 30 Mask seal 31 Opening 41 Metal thin film

Claims

1. An autonomous mobile sensing device comprising a permeable film, a catalyst disposed inside a space formed by the permeable film, and a product accumulation layer formed inside the space, wherein the permeable film is made of a material that is permeable to a substance that reacts with the catalyst but is impermeable to a product generated by the substance and the catalyst.

2. The autonomous mobile sensing device of claim 1, further comprising a central portion, a first layer surrounding the periphery of the central portion, and a second layer surrounding the periphery of the first layer, wherein the central portion is the product accumulation layer, the first layer is the catalyst, and the second layer is the transparent film.

3. An autonomous mobile sensing device as described in claim 1, further comprising: a solid substrate; a first layer disposed on one side of the solid substrate; and a second layer covering one side of the solid substrate and the first layer and adhered via an adhesive layer to an area of ​​the one side of the solid substrate excluding the first layer and its peripheral edge, wherein the first layer is the catalyst, the second layer is the permeable film, the solid substrate and a space between the first layer and the second layer is the product accumulation layer, and the adhesive layer has an adhesive interface that adheres the solid substrate to the second layer and a non-adhesive interface that does not adhere the solid substrate to the second layer.

4. A method for manufacturing an autonomous mobile sensing device, comprising the steps of: providing a mask seal having an opening on one surface of a solid substrate; applying a metal coating to an exposed portion of the one surface of the solid substrate that is exposed in the opening, thereby forming a metal thin film on the exposed portion; removing the mask seal from the one surface of the solid substrate; and covering the one surface of the solid substrate and the metal thin film, and adhering a permeable film via an adhesive layer to an area of ​​the one surface of the solid substrate excluding the metal thin film and its peripheral edge, wherein in the step of adhering the permeable film, the adhesive layer forms a layer having an adhesive interface that adheres the solid substrate and the permeable film, and a non-adhesive interface that does not adhere the solid substrate and the permeable film.

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