KR102360933B1 - Methods of porous self-sorting pressure sensor and self-sorting pressure sensor prepared thereby - Google Patents

Abstract

Disclosed are a manufacturing method of an autonomous determination pressure sensor, and an autonomous determination pressure sensor manufactured thereby. The manufacturing method of an autonomous determination pressure sensor comprises: a step of manufacturing a substrate having a recess unit and a protrusion unit; a step of coating a metal nanoparticle surrounded by a first ligand on the recess unit and the protrusion unit of the substrate; a step of proceeding a ligand substitution process by using the metal nanoparticle surrounded by the first ligand to form a sensing unit; and a step of arranging an electrode to face the substrate. The sensing unit comprises: a conductive layer formed on the recess unit of the substrate; and a semi-insulating layer formed on the protrusion unit of the substrate.

Description

Manufacturing method of autonomous type judgment pressure sensor and autonomous type judgment pressure sensor manufactured through the same

The present invention relates to a method for manufacturing an autonomous judgment pressure sensor and an autonomous judgment pressure sensor manufactured through the same, and more particularly, to a heterogeneous structure pattern (conductive layer and semi-conductive layer) through selective chemical treatment (second ligand substitution process) It relates to a method of manufacturing an autonomous judgment pressure sensor capable of sensing step by step according to the degree of pressure using an insulating layer), and to an autonomous judgment pressure sensor manufactured through the same.

Recently, as wearable devices are grafted onto the Internet of Things, not only the function of detecting the position and strength of the existing pressure, but also the function of the device performing a specific function according to the degree of pressure is required.

In addition, as interest in health care has recently increased, interest in a pressure measuring device, which is a key component thereof, is also increasing. Various structures have been devised to realize a high-performance pressure measuring device that detects minute pressures such as pulse and blood pressure.

However, since this structure is currently manufactured through a process that requires high temperature and high pressure conditions, it requires expensive equipment and faces limitations in that it is difficult to use various materials.

In addition, in previous studies, it was necessary to separate the signal received from the sensor using programming to implement this technology, and the method using programming requires a complex circuit. This causes problems in that it is difficult to form a circuit on a very thin flexible substrate, the reliability is lowered, and the manufacturing cost is rapidly increased.

In addition, when a large amount of information such as a large-area sensor or electronic skin needs to be processed simultaneously, a delay is caused between the sensor and the actual operation time, and a lot of energy is consumed for calculation.

Accordingly, there is an urgent need to develop a technology capable of efficiently determining a large amount of information with only a minimum of calculations.

Republic of Korea Patent No. 2045473, "Nanowire array manufacturing method and strain sensor manufacturing method including the same" Republic of Korea Patent No. 2135296, "Manufacturing method of pressure sensor and pressure sensor manufactured therefrom"

An embodiment of the present invention forms a sensing unit having a heterogeneous structure (conductive layer and semi-insulating layer) through selective chemical treatment (second ligand substitution process) on a substrate including fine concavo-convex structures (concave portions and protrusions) An object of the present invention is to provide a method for manufacturing an autonomous judgment pressure sensor capable of determining the degree of pressure by simply using only a measured current value, and an autonomous judgment pressure sensor manufactured through this method.

An embodiment of the present invention forms a sensing unit having a heterogeneous structure (a conductive layer and a semi-insulating layer) through selective chemical treatment (second ligand substitution process), and the entire process is prepared as a solution process at normal pressure and room temperature. An object of the present invention is to provide a method for manufacturing an autonomous judgment pressure sensor that can be easily mass-produced while reducing the cost and an autonomous judgment pressure sensor manufactured through this method.

A method of manufacturing an autonomous judgment pressure sensor according to an embodiment of the present invention includes manufacturing a substrate including concave portions and protrusions, and coating metal nanoparticles surrounded by a first ligand on the concave portions and protrusions of the substrate. , forming a sensing unit by performing a ligand substitution process using metal nanoparticles surrounded by the first ligand, and disposing an electrode to face the substrate, wherein the sensing unit is conductive formed on the concave portion of the substrate a conductive layer and a semi-insulating layer formed on the protrusion of the substrate.

The step of forming the sensing unit by performing a ligand substitution process using the metal nanoparticles surrounded by the first ligand may include selectively removing the metal nanoparticles surrounded by the first ligand formed on the protrusion using an adhesion layer; Forming a first metal nanoparticle layer comprising metal nanoparticles surrounded by a second ligand by substituting the first ligand through a ligand substitution process, and using the first ligand on the substrate on which the first metal nanoparticle layer is formed It may include coating the surrounded metal nanoparticles and substituting the first ligand through a second ligand substitution process to form a second metal nanoparticle layer including the metal nanoparticles surrounded by the third ligand.

In the second ligand substitution process, the resistance of the metal nanoparticles surrounded by the third ligand may be controlled according to the presence or absence of the metal nanoparticles surrounded by the second ligand.

The third ligand may have a shorter length than the first ligand and the second ligand.

The first ligand and the second ligand may include an organic ligand, and the third ligand may be surrounded by an inorganic ligand.

In the step of selectively removing the metal nanoparticles surrounded by the first ligand formed on the protrusion using the adhesion layer, 80% to 99% of the metal nanoparticles surrounded by the first ligand formed on the protrusion by the adhesion layer are removed can be

In the semi-insulating layer, the density of the metal nanoparticles surrounded by the second ligand and the metal nanoparticles surrounded by the third ligand may be lower than that of the conductive layer.

The semi-insulating layer may be thinner than the conductive layer.

The width of the protrusion of the substrate may be 10 μm to 10 mm.

The height of the protrusion of the substrate may be 5 μm to 5 mm.

An autonomous judgment pressure sensor according to an embodiment of the present invention includes a substrate including a concave portion and a protrusion, a sensing unit formed on the concave and protrusion of the substrate, and an electrode disposed to face the substrate, The portion includes a conductive layer formed on the concave portion of the substrate and a semi-insulating layer formed on the protrusion portion of the substrate.

The conductive layer may include a first metal nanoparticle layer including metal nanoparticles surrounded by a second ligand and a second metal nanoparticle layer including metal nanoparticles surrounded by a third ligand.

The semi-insulating layer may include a first metal nanoparticle layer including metal nanoparticles surrounded by a second ligand and a second metal nanoparticle layer including metal nanoparticles surrounded by a third ligand.

In the semi-insulating layer, the density of the metal nanoparticles surrounded by the second ligand and the metal nanoparticles surrounded by the third ligand may be lower than that of the conductive layer.

The autonomous judgment pressure sensor may detect pain and tactile sensations.

According to an embodiment of the present invention, a sensing unit having a heterogeneous structure (conductive layer and semi-insulating layer) through selective chemical treatment (second ligand substitution process) on a substrate including fine concavo-convex structures (recesses and protrusions) It is possible to provide a method for manufacturing an autonomous judgment pressure sensor capable of determining the degree of pressure using only the current value that is formed and simply measured, and an autonomous judgment pressure sensor manufactured through this method.

According to an embodiment of the present invention, a sensing part having a heterogeneous structure (conductive layer and semi-insulating layer) is formed through selective chemical treatment (second ligand substitution process) to prepare the entire process as a solution process at normal pressure and room temperature, It is possible to provide a method for manufacturing an autonomous judgment pressure sensor that can be easily mass-produced while reducing manufacturing cost, and an autonomous judgment pressure sensor manufactured through this method.

1 is a cross-sectional view illustrating a method of manufacturing an autonomous judgment pressure sensor according to an embodiment of the present invention.
2 is a schematic diagram illustrating a step of manufacturing a substrate in a method for manufacturing an autonomous judgment pressure sensor according to an embodiment of the present invention.
3 is a cross-sectional view illustrating step S134 of a method for manufacturing an autonomous judgment pressure sensor according to an embodiment of the present invention.
4 is a graph showing a cross-sectional view and a current change of a conventional pressure sensor.
5 is a graph and a cross-sectional view illustrating a cross-sectional view and a current change of an autonomous judgment pressure sensor according to an embodiment of the present invention.
6 is an image showing a scanning electron microscope image and Energy Dispersive Spectroscopy-Mapping (EDS-Mapping) of a pressure sensor that does not include an adhesion layer.
7 is an image showing a scanning electron microscope image and energy dispersive spectral-mapping of an autonomous judgment pressure sensor according to Embodiment 1 of the present invention including an adhesion layer.
8 is a graph illustrating a change in current when a pressure of 250 Pa is applied to the autonomous judgment pressure sensor according to Example 1 of the present invention.
9 is a graph illustrating a change in current when a pressure of 1000 Pa is applied to the autonomous judgment pressure sensor according to Example 1 of the present invention.
10 is a graph illustrating a change in current when a pressure of 2500 Pa is applied to the autonomous judgment pressure sensor according to Example 1 of the present invention.
11 is a graph illustrating a relative current change ((I _on -I _off )/I _off ) when a pressure of 250 Pa is applied to the autonomous judgment pressure sensor according to Example 1 of the present invention.
12 is a graph illustrating a relative current change ((I _on -I _off )/I _off ) when a pressure of 1000 Pa is applied to the autonomous judgment pressure sensor according to Example 1 of the present invention.
13 is a graph illustrating a relative current change ((I _on -I _off )/I _off ) when a pressure of 2500 Pa is applied to the autonomous judgment pressure sensor according to Example 1 of the present invention.
14 is a graph illustrating a relative current change (Normalized (I _on -I _off )/I _off ) according to the pressure of the autonomous judgment pressure sensor according to Embodiment 1 of the present invention.
15 is a graph showing the change in current according to the pressure of the autonomous judgment pressure sensor according to Example 2 of the present invention manufactured using ITO nanoparticles.
16 and 17 are images illustrating sensing results according to pressure of the autonomous judgment pressure sensor according to Embodiment 2 of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings and contents described in the accompanying drawings, but the present invention is not limited or limited by the embodiments.

The terminology used herein is for the purpose of describing the embodiments and is not intended to limit the present invention. In this specification, the singular also includes the plural unless specifically stated otherwise in the phrase. As used herein, "comprises" and/or "comprising" does not exclude the presence or addition of one or more other elements, steps, or elements mentioned.

As used herein, “embodiment”, “example”, “aspect”, “exemplary”, etc. are to be construed as advantageous in any aspect or design described as being preferred or advantageous over other aspects or designs. is not doing

Also, the term 'or' means 'inclusive or' rather than 'exclusive or'. That is, unless stated otherwise or clear from context, the expression 'x employs a or b' means any of natural inclusive permutations.

Also, as used herein and in the claims, the singular expression "a" or "an" generally means "one or more," unless stated otherwise or clear from the context that it relates to the singular form. should be interpreted as

The terms used in the description below have been selected as general and universal in the related technical field, but there may be other terms depending on the development and/or change of technology, customs, preferences of technicians, and the like. Therefore, the terms used in the description below should not be construed as limiting the technical idea, but as illustrative terms for describing the embodiments.

In addition, in a specific case, there is a term arbitrarily selected by the applicant, and in this case, the meaning will be described in detail in the corresponding description. Therefore, the terms used in the description below should be understood based on the meaning of the term and the content throughout the specification, rather than the simple name of the term.

Unless otherwise defined, all terms (including technical and scientific terms) used herein may be used with the meaning commonly understood by those of ordinary skill in the art to which the present invention belongs. In addition, terms defined in a commonly used dictionary are not to be interpreted ideally or excessively unless clearly defined in particular.

Meanwhile, in the description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. In addition, the terms used in this specification are terms used to properly express the embodiment of the present invention, which may vary according to the intention of a user or operator or customs in the field to which the present invention belongs. Accordingly, definitions of these terms should be made based on the content throughout this specification.

1 is a cross-sectional view illustrating a method of manufacturing an autonomous judgment pressure sensor according to an embodiment of the present invention.

A method of manufacturing an autonomous judgment pressure sensor according to an embodiment of the present invention includes manufacturing the substrate 110 including the concave portion 111 and the protruding portion 112 ( S110 ), and the concave portion 111 of the substrate 110 . ) and the step of coating the metal nanoparticles 120 surrounded by the first ligand on the protrusion 112 (S120), and performing a ligand substitution process using the metal nanoparticles 120 and 121 surrounded by the first ligand to proceed with the sensing unit It includes forming steps 161 and 162 ( S120 to S134 ) and disposing electrodes to face the substrate 110 .

The sensing units 161 and 162 include a conductive layer 161 formed on the concave portion 111 of the substrate 110 and a semi-insulating layer formed on the protrusion 112 of the substrate 110 . insulating layer; 162).

Therefore, in the method of manufacturing the autonomous judgment pressure sensor according to the embodiment of the present invention, selective chemical treatment (ligand substitution process) on the substrate 110 including the fine concavo-convex structure (the concave portion 111 and the protrusion 112 ) By forming the sensing units 161 and 162 having a heterogeneous structure (the conductive layer 161 and the semi-insulating layer 162), the degree of pressure can be determined using only the measured current value.

In addition, the manufacturing method of the autonomous judgment pressure sensor according to the embodiment of the present invention forms a sensing unit having a heterogeneous structure (conductive layer 161 and semi-insulating layer 162) through selective chemical treatment (ligand substitution process). Thus, by manufacturing the entire process as a solution process at normal pressure and room temperature, it is possible to reduce manufacturing cost and easily mass-produce.

First, the method of manufacturing the autonomous judgment pressure sensor according to the embodiment of the present invention proceeds with the step (S110) of manufacturing the substrate 110 including the concave portion 111 and the protrusion 112 .

Step S110 will be described with reference to FIG. 2 .

2 is a schematic diagram illustrating a step of manufacturing a substrate in a method for manufacturing an autonomous judgment pressure sensor according to an embodiment of the present invention.

According to an embodiment, the step (S110) of manufacturing the substrate 110 including the concave portion and the protrusion includes the step of preparing a mold (Mold, M) including the concave portion and the protrusion (S111), the mold M It may include a step of coating and curing the substrate-forming material on (S112) and removing the mold (M) to obtain the substrate 110 including concave portions and protrusions (S113).

First, the step of preparing the mold (Mold, M) including the concave portion and the protrusion (S111) may proceed.

The mold M includes concave portions and protrusions, and the concave portions of the mold M may correspond to the protrusions of the substrate 110 , and the protrusions of the mold M correspond to the concave portions of the substrate 110 ). It can be formed to be

Polydimethylsiloxane (PDMS) may be used as the mold M, but is not limited thereto.

After that, the step ( S112 ) of coating and curing the substrate-forming material on the mold M may be performed.

For example, the substrate forming material is spray coated on the mold M, spin coating, ultra-spray coating, electrospinning coating, slot die coating, etc. , gravure coating, bar coating, roll coating, dip coating, shear coating, screen printing, inkjet printing and It may be coated by at least one method of nozzle printing.

The substrate-forming material coated on the mold M may be cured by thermal curing or photocuring.

Finally, a step (S113) of removing the mold M to obtain the substrate 110 including the concave portion and the protruding portion may be performed.

When the mold M is removed after curing the substrate-forming material, the substrate 110 having the concave portions 111 and the protruding portions 112 formed thereon can be obtained.

The substrate 110 may be made of glass, quartz, Al ₂ O ₃ , SiC, Si, GaAs, InP, or a flexible substrate, but is not limited thereto.

Preferably, since the substrate 110 must be deformed by the movement of the measurement target or deformed by an external force, a flexible substrate having flexibility and insulation may be used.

For example, flexible substrates include polydimethylsiloxane (PDMS), polyimide (PI), polyethersulfone (PES), polyacrylate (PAR), and polyetherimide (PEI). ), polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polyarylate (polyarylate), polycarbonate (PC), cellulose tree It may be made of at least one polymer material of acetate (cellulose triacetate, CTA) and cellulose acetate propionate (CAP), and preferably, the substrate 110 may be made of PDMS, but is limited thereto. it is not

Hereinafter, with reference to FIG. 1 again, it will be described.

The concave portions 111 and the protrusions 112 formed on the substrate 110 may be formed regularly or may be formed randomly.

When the recesses 111 and the protrusions 112 formed on the substrate 110 are regularly formed, pressure is uniformly applied in the step of removing the metal nanoparticles 120 surrounded by the first ligand to form a regular pattern of the first metal The nanoparticle layer 140 may be formed, and when the recesses 111 and the protrusions 112 formed on the substrate 110 are randomly and irregularly formed, the metal nanoparticles 120 surrounded by the first ligand are removed. In this step, pressure is not applied uniformly, so that the first metal nanoparticle layer 140 may be irregularly formed.

Accordingly, the concave portion 111 and the protruding portion 112 may be formed regularly or irregularly according to a shape in which the first metal nanoparticle layer 140 is to be formed.

The width d of the protrusion 112 of the substrate 110 may be 10 μm to 10 mm.

Since the thickness of the sensing unit formed on the substrate 110 should be at least 3 nm to 400 nm, the protrusion 112 should have a width d of at least 10 μm or more in order to form a stable pattern.

In addition, when the width d of the protrusion 112 exceeds 10 mm, the number of patterns driven as a sensor per unit area decreases, and thus there is a problem in that sensitivity is lowered.

The height h of the protrusion 112 of the substrate 110 may be 5 μm to 5 mm.

In order to operate as a wearable pressure sensor, it must be able to sense a pressure of at least 10 kPa or more, so to make a sensor with a pressure range that can be driven with a pressure of 10 kPa or more, it must have a pattern with a height of at least 5 um.

However, when the height h of the protrusion 112 of the substrate 110 exceeds 5 mm or more, the height h is too high and the conductive layer 161 or semi-insulating layer 162 is changed by a change in pressure. Since the change in the contact area between the electrode and the electrode is reduced, there is a problem in that the sensitivity is lowered.

Thereafter, in the method for manufacturing the autonomous judgment pressure sensor according to the embodiment of the present invention, the metal nanoparticles 120 surrounded by the first ligand are coated on the concave portion 111 and the protrusion 112 of the substrate 110 . Proceed to step S120.

The metal nanoparticles 120 surrounded by the first ligand may include at least one of silver (Ag), indium tin oxide (ITO), gold (Au), iron (Fe), palladium (Pd), and copper (Cu). It may include one metal nanoparticle.

The first ligand may include an organic ligand, for example, the first ligand may include at least one of trioctylphosphineoxide (TOPO), octadecanol, and oleate.

Preferably, the metal nanoparticles 120 surrounded by the first ligand may be silver nanoparticles surrounded by the oleate ligand.

In addition, the metal nanoparticles 120 surrounded by the first ligand may be subjected to spray coating, spin coating, ultra-spray coating, electrospinning coating, or slot die coating. , gravure coating, bar coating, roll coating, dip coating, shear coating, screen printing, inkjet printing, or It may be applied on the substrate 110 by nozzle printing, and preferably, the metal nanoparticles 120 surrounded by the first ligand may be coated on the substrate 110 by spin coating, but the present invention is limited thereto. it is not going to be

Thereafter, the method for manufacturing the autonomous judgment pressure sensor according to an embodiment of the present invention includes the steps of forming the sensing units 161 and 162 by performing a ligand substitution process using the metal nanoparticles 120 surrounded by the first ligand ( S120 to S134) are performed.

According to an embodiment, the step of forming the sensing unit by performing a ligand substitution process using the metal nanoparticles 120 surrounded by the first ligand includes attaching the metal nanoparticles 120 surrounded by the first ligand formed on the protrusion 112 . The first metal nanoparticle layer 140 including the metal nanoparticles 140 surrounded by the second ligand by replacing the first ligand through a step (S131) of selectively removing the layer 130 using the first ligand substitution process ) forming (S132), coating the metal nanoparticles 120 surrounded by the first ligand on the substrate 110 on which the first metal nanoparticle layer 140 is formed, and the second ligand substitution process. It may include forming the second metal nanoparticle layer 150 including the metal nanoparticle 150 surrounded by the third ligand by substituting the ligand.

First, the metal nanoparticles 120 surrounded by the first ligand formed on the protrusion 112 may be selectively removed using the adhesion layer 130 ( S131 ).

The adhesive layer 130 is a layer having a large van der Waals force. For example, the adhesive layer 130 may use a tape or an adhesive, but is not limited thereto.

After arranging the upper surface of the substrate 110 (the surface on which the concave portion 111 and the protrusion 112 coated with the metal nanoparticles 120 surrounded by the first ligand) are formed in contact with the adhesive surface of the adhesion layer 130 ) , When a pressure (hereinafter, referred to as a removal pressure) is applied to the back surface of the substrate 110 (the surface on which the metal nanoparticles 120 surrounded by the first ligand is not formed), and then the substrate 110 is removed, The metal nanoparticles 120 surrounded by the first ligand formed on the protrusions 112 of the substrate 110 that were adhered to the adhesion layer 130 may be removed.

All of the metal nanoparticles 120 surrounded by the first ligand formed on the protrusion 112 may be removed, or almost all of the metal nanoparticles 120 surrounded by the first ligand may remain in a very small amount. The metal nanoparticles 120 surrounded by the first ligand may be formed on the protrusion 112 to have a relatively very low density or concentration than that of the concave portion 111 .

Accordingly, in the recess 111 of the substrate 110, the metal nanoparticles 120 surrounded by the first ligand are present at a high density, but in the protrusion 112, the metal nanoparticles 120 surrounded by the first ligand are very low. A heterogeneous structure may be formed on the substrate 110 because it exists in density or does not exist.

That is, the range and density in which the metal nanoparticles 120 surrounded by the first ligand formed on the protrusion 112 are selectively removed according to the removal pressure applied to the back surface of the substrate 110 may be controlled.

The removal pressure may be 200 Pa to 10 kPa, and if the removal pressure is less than 200 Pa, there is a problem that the metal nanoparticles 120 surrounded by the first ligand formed on the protrusion 112 are not removed because the removal pressure is small, When it exceeds 10 kPa, there is a problem in that the metal nanoparticles 120 surrounded by the first ligand formed on the concave portion 110 are removed.

The metal nanoparticles 120 surrounded by the first ligand removed from the protrusion 112 by the adhesion layer 130 may be 80% to 99%, and the metal nanoparticles 120 surrounded by the removed first ligand are 80%. %, the difference between the semi-insulating layer 162 and the conductive layer 161 is small, so that the concave portion 111 of the substrate 110 has conductivity and thus does not have a heterogeneous structure.

According to an embodiment, 99% means that when removing the metal nanoparticles 120 surrounded by the first ligand using the adhesion layer 130 , it is no longer surrounded by the first ligand in the adhesion layer 130 with the naked eye. It means when the metal nanoparticles 120 are removed to the extent that they do not come off, and this may have the same meaning as 100% removal.

Accordingly, the metal nanoparticles 120 surrounded by the first ligand formed on the concave portion 111 of the substrate 110 may have a density of 30% to 74%, and on the protrusion 112 of the substrate 110 . The metal nanoparticles surrounded by the formed first ligand may have a density of 1% to 15%.

Since the metal nanoparticles 120 surrounded by the first ligand formed on the substrate 110 are nano-scale materials, it is difficult to accurately express the density in number/cm ³ , but the density can be indirectly measured with electrical properties. can

The concave portion 111 to become the conductive layer 161 and the protrusion 112 to become the semi-insulating layer 162 exhibit a large difference in resistivity, and the resistivity (Ω*cm) of the concave portion 111 is It may have a range of 1 X 10 ^-2 to 3.4 X 10 ^-4 , and the protrusion 12 may have a range of 2 X 10 ² to 1 X 10 ⁴ .

At this time, assuming that the metal nanoparticles have a spherical shape, it is lower than the closed packing density of 0.74, and in general, since the metal nanoparticles are randomly arranged at random, the packing density is It may be about 0.4 to 0.5.

Accordingly, the packing density of the metal nanoparticles 120 surrounded by the first ligand formed on the concave portion 111 serving as the conductive layer 161 of the substrate 110 may be 0.3 to 0.74.

In addition, in the method of manufacturing an autonomous pressure sensor according to an embodiment of the present invention, the metal nanoparticles 121 surrounded by the first ligand to a predetermined height of the substrate 110 or less by selectively removing the adhesive layer 130 . can be removed

The height at which the metal nanoparticles 120 surrounded by the first ligand are removed by the adhesion layer 130 may be 40 μm to 500 μm, and the height at which the metal nanoparticles 120 surrounded by the first ligands are removed is less than 40 μm. There is a problem in that the backside removal pressure is too small to keep it constant, and when it exceeds 500 μm, even the metal nanoparticles 121 surrounded by the first ligand formed on the concave portion 111 are removed.

Thereafter, a step (S132) of forming the first metal nanoparticle layer 140 including the metal nanoparticles 140 surrounded by the second ligand by substituting the first ligand through the first ligand substitution process may be performed.

An organic ligand may be used as the second ligand, and preferably, a ligand containing a thiol group may be used as the second ligand, and more preferably, the second ligand is 3-mercaptopropionic acid (MPA). ) and 1,2-ethanedithiol (1,2-ethaneedithiol, EDT) may include at least one.

For example, 1,2-ethanedithiol (1,2-ethanedithiol, EDT) ligand has a structure including thiol groups on both sides like HSCCSH, and 1,2-ethanedithiol (1,2-ethanedithiol, EDT) ) The ligand has lower electrical properties than chlorine (Cl ⁻ ), but has superior conductivity than the oleate ligand, and may exhibit a strong bonding force with the metal nanoparticles 150 including the third ligand,

The first metal nanoparticle layer 140 is formed by removing the metal nanoparticles 120 surrounded by the first ligand formed on the protrusion 112 of the substrate 110 using the adhesion layer 130 , and then performing a first ligand substitution process. Since the first metal nanoparticle layer 140 including the metal nanoparticles 140 surrounded by the second ligand is formed by proceeding, the first metal nanoparticle layer 140 is formed to have a heterogeneous structure on the concave portion 111 and the protruding portion 112 of the substrate 110 . One metal nanoparticle layer 140 may be formed.

More specifically, the first metal nanoparticle layer 140 is not formed on the protrusion 112 of the substrate 110, or the first metal nanoparticle layer 140 is surrounded by the metal nanoparticles 140 surrounded by the second ligand. It contains a low concentration or density, and the first metal nanoparticle layer is formed on the concave portion 111 of the substrate 110 at a high concentration or density to have a heterogeneous structure.

In addition, the first metal nanoparticle layer 140 formed on the protrusion 112 of the substrate 110 is surrounded by the second ligand rather than the first metal nanoparticle layer 140 formed on the recess 111 of the substrate 140 . Since the density of the metal nanoparticles is relatively low, the thickness of the first metal nanoparticle layer 140 formed on the protrusion 112 of the substrate 110 is the same as the thickness of the first metal nanoparticle layer 140 formed on the concave portion 111 of the substrate 140 . It may be smaller than the thickness of the nanoparticle layer 140 .

After that, a step (S133) of coating the metal nanoparticles 120 surrounded by the first ligand on the substrate 110 on which the first metal nanoparticle layer 140 is formed may be performed.

The step of coating the metal nanoparticles 120 surrounded by the first ligand on the substrate 110 on which the first metal nanoparticle layer 140 is formed ( S133 ) is the concave portion 111 and the protruding portion 112 of the substrate 110 . Since it may proceed with the same material or method as the step (S120) of coating the metal nanoparticles 120 surrounded by the first ligand on the surface, the same components will be omitted.

Finally, the step (S134) of forming the second metal nanoparticle layer 150 including the metal nanoparticle 150 surrounded by the third ligand by substituting the first ligand through the second ligand substitution process may be performed.

Step S134 will be described in more detail with reference to FIG. 3 .

3 is a cross-sectional view illustrating step S134 of a method for manufacturing an autonomous judgment pressure sensor according to an embodiment of the present invention.

The third ligand may include an inorganic ligand, and preferably, the third ligand is a sulfur ion (S ² − ), a chlorine ion (Cl ⁻ ), a bromine ion (Br ⁻ ), a thiocyanate ion (SCN ⁻ ). , iodine ion (I ^- ), disulfide ion (HS ^- ), tellurium ion (Te ^2- ), hydroxide ion (OH ^- ), tetrafluoroborate ion (BF ^4- ) and hexafluorophosphate ion (PF ⁶ ) ^- ), and more preferably, the third ligand may be a halide ligand.

The halide ligand includes at least one of a chlorine ion (Cl ^- ), a bromine ion (Br ^- ), an iodine ion (I ^- ), a tetrafluoroborate ion ( ^BF4- ), and a hexafluorophosphate ion ( ^PF6- ) and preferably, the third ligand may be a chlorine ion (Cl ⁻ ) ligand.

Since the halide ligand exhibits higher conductivity than other ligands, the use of the halide ligand as the third ligand may further improve the sensitivity of the pressure sensor.

Therefore, as the third ligand, an inorganic ligand shorter than the first ligand and the second ligand may be used, and the third ligand may be an inorganic ligand shorter than the first ligand and the second ligand, so that the distance between the metal nanoparticles is shortened to almost 0, so that all fusions between the fine clusters proceed, thereby indicating conductivity.

For example, in the second ligand substitution process, when NH ₄ Cl is dissolved in a polar solvent, it is ionized into NH ⁴⁺ and Cl ⁻ . When this solution is coated on the substrate 110 on which the first metal nanoparticle layer 140 is formed, + Chloride ions (Cl ⁻ ) are bonded to the surface of the metal nanoparticles of the metal nanoparticles 140 surrounded by the charged second ligand, and the second ligand is removed together with the polar solvent so that the second ligand is removed from the third It may be substituted with a chlorine ion (Cl ⁻ ) as a ligand.

Forming the second metal nanoparticle layer 150 including the metal nanoparticle 150 surrounded by the third ligand by substituting the first ligand through the second ligand substitution process ( S134 ) is the first step on the substrate 110 . On the substrate 110 on which the metal nanoparticles 140 surrounded by the two ligands are not formed under the metal nanoparticles 120 surrounded by the ligands, the third ligand has an aggregation effect, and the metal nanoparticles 120 surrounded by the first ligands 120 ) on the substrate on which the metal nanoparticles 140 surrounded by the second ligand are formed on the lower portion of the metal nanoparticles surrounded by the third ligand on the metal nanoparticles 140 selectively surrounded by the second ligand by using those that do not have an aggregation effect By forming the particles 150 , a semi-insulating layer 161 is formed on the protrusion 111 of the substrate 110 , and a conductive layer is formed on the recess 112 of the substrate 110 . 162) can be formed

More specifically, when all the metal nanoparticles 140 surrounded by the second ligand are removed on the protrusion 112 of the substrate 110 and the first metal nanoparticle layer 140 is not formed, the second ligand substitution process is performed. As it proceeds, since the first metal nanoparticle layer 140 serving as an adhesive layer does not exist on the protrusion 112 of the substrate 110, the metal nanoparticles 120 surrounded by the first ligand by the strong aggregation effect of the third ligand. may be aggregated while being replaced by the metal nanoparticles 150 surrounded by the third ligand and removed on the protrusion 112 of the substrate 110 .

If the first metal nanoparticle layer 140 having a low density is formed on the protrusion 112 of the substrate 110 by including the metal nanoparticles 140 surrounded by the second ligand at an extremely low concentration or density, the substrate The first metal nanoparticle layer 140 serving as an adhesive layer on the protrusion 112 of 110 has a very low density of the metal nanoparticles 140 surrounded by the second ligand, and is replaced with a second ligand on the protrusion 112 . It may include a region in which the metal nanoparticles 140 are formed and a region in which the metal nanoparticles 140 displaced by the second ligand are not formed.

At this time, when the second ligand substitution process is performed, the region in which the metal nanoparticles 140 substituted with the second ligand are not formed due to the strong aggregation effect of the third ligand due to the strong aggregation effect of the third ligand. The metal nanoparticles 120 surrounded by the first ligand are agglomerated while being replaced by the metal nanoparticles 150 surrounded by the third ligand, and can be removed from the protrusion 112 of the substrate 110, and replaced with the second ligand at the bottom. In the region where the metal nanoparticles 140 are formed, the metal nanoparticles 140 substituted with the second ligand act as an adhesive layer, and the metal nanoparticles 120 surrounded by the first ligand formed on the first metal nanoparticle layer 140 are formed. may be substituted with the metal nanoparticles 150 surrounded by the third ligand.

Accordingly, the semi-insulating layer 162 having semi-insulating properties may be formed as the protrusion 112 of the substrate 110 does not contain or contains the metal nanoparticles substituted with the third ligand at a low density.

Semi-insulating means having a very low conductivity, and the electrical conductivity of the semi-insulating layer 162 may be 2 X 10 ² to 1 X 10 ⁴ Ω*cm.

This is a value when the metal nanoparticles 120 surrounded by 80% to 100% of the first ligand compared to the conductive layer 161 are removed.

Accordingly, the packing density of the semi-insulating layer 162 may range from 0 to 0.15, with 80% to 100% removed from the 0.3 to 0.74 packing density of the conductive layer 161 .

If the first metal nanoparticle layer 140 is formed on the concave portion 111 of the substrate 110, when the second ligand substitution process is performed, the lower portion of the metal nanoparticle 120 surrounded by the first ligand The formed metal nanoparticles 140 surrounded by the second ligand act as an adhesive layer, so that the metal nanoparticles 120 surrounded by the first ligand are ligand-substituted and the metal nanoparticles 150 surrounded by the third ligand are resistant to the aggregation effect. Thus, the second metal nanoparticle layer 150 may be formed on the first metal nanoparticle layer 140 .

Accordingly, the concave portion 111 of the substrate 110 may include the metal nanoparticles surrounded by the third ligand at a high density to form the conductive layer 162 having conductivity.

For example, when a thiol-group ligand is used as the second ligand, the metal nanoparticles 150 surrounded by the third ligand are strongly bound to the thiol-group ligand formed thereunder to have resistance to the aggregation effect of the third ligand. can

Therefore, in the second ligand substitution process, the metal nanoparticles 150 surrounded by the third ligand according to the presence or absence of the metal nanoparticles 140 surrounded by the second ligand under the metal nanoparticles 120 surrounded by the first ligand. Resistance can be controlled.

In addition, since the semi-insulating layer 162 is formed with a lower density of the metal nanoparticles 140 surrounded by the second ligand than the conductive layer 161 , the thickness of the semi-insulating layer 162 is greater than that of the conductive layer 161 . can be thin.

Accordingly, the conductive layer 161 is formed in the concave portion 111 of the sensing unit and the semi-insulating layer 162 is formed in the protruding portion 112 by the method of manufacturing the autonomous judgment pressure sensor according to the embodiment of the present invention. It may be a heterogeneous structure.

For this reason, in the method of manufacturing an autonomous judgment pressure sensor according to an embodiment of the present invention, the metal nanoparticles 140 surrounded by the second ligand and the metal nanoparticles 150 surrounded by the third ligand are regularly formed to have a constant height. By coating the concave portion 111 and the protruding portion 112 of the substrate 110 , a change in resistance according to pressure may be sensitively detected.

In addition, the method for manufacturing an autonomous judgment pressure sensor according to an embodiment of the present invention strongly presses the metal nanoparticles 150 surrounded by the third ligand on the substrate 110 including the concave portion 111 and the protrusion 112 . The metal nanoparticles 120 surrounded by the first ligand coated on the protrusions 112 of the substrate 110 are easily and selectively removed at room temperature and pressure by forming the first metal nanoparticle layer (the role of the adhesive layer; 140) to adhere. can do.

Finally, although not shown in FIG. 1 , the method includes disposing an electrode to face the substrate 110 .

The electrode may be formed as a thin film on the substrate, and the same material as the substrate 110 may be used for the substrate, but is not limited thereto.

The electrodes are electrically connected to the sensing units 161 and 162 and may be made of a conductive material for this purpose.

Electrodes are gold (Au), silver (Ag), platinum (Pt), fluorine-doped tin oxide (FTO), indium-doped tin oxide (ITO), aluminum-containing zinc oxide (Al-) doped zinc oxide (AZO) and indium-containing zinc oxide (Indium doped zinc oxide, IZO) may include at least one, but is not limited thereto.

4 is a graph showing a cross-sectional view and a current change of a conventional pressure sensor.

A conventional pressure sensor may include a sensing unit 20 formed on a substrate 10 having an uneven pattern, and an electrode 30 may be disposed to face the substrate 10 .

A sensing unit 20 is formed to connect two different (physically separated) electrodes 30 , and a current travels through the conductive layer 20 from the electrode 30 to another electrode formed on the substrate 10 . will flow to

When the pressure in the pressure sensor increases, the area in which the sensing unit 20 comes into contact with the electrode 30 increases, and accordingly, the path through which the current can flow is widened, so that as the pressure increases, the two The current flowing between the electrodes 30 may be increased.

However, since the conventional pressure sensor is not formed to have a heterogeneous structure in the sensing unit 20, it is formed to have a single inclination and cannot operate as a sensor below a specific pressure.

5 is a graph and a cross-sectional view illustrating a cross-sectional view and a current change of an autonomous judgment pressure sensor according to an embodiment of the present invention.

Since the autonomous judgment pressure sensor according to the embodiment of the present invention is manufactured by the manufacturing method of the autonomous judgment pressure sensor according to the embodiment of the present invention, a description of the same components will be omitted.

The autonomous judgment pressure sensor according to an embodiment of the present invention is disposed to face the substrate 110 including the concave portion and the protrusion, the sensing unit formed on the concave and protruding portions of the substrate 110 and the substrate 110 . It includes an electrode 170 .

The sensing unit may have a heterogeneous structure including a conductive layer 161 formed on the concave portion of the substrate 110 and a semi-insulating layer 162 formed on the protrusion of the substrate 110 .

The conductive layer 161 may include a first metal nanoparticle layer including metal nanoparticles surrounded by a second ligand and a second metal nanoparticle layer including metal nanoparticles surrounded by a third ligand.

The semi-insulating layer 162 does not include a first metal nanoparticle layer including metal nanoparticles surrounded by a second ligand and a second metal nanoparticle layer including metal nanoparticles surrounded by a third ligand, or the conductive layer 161 ) may include a first metal nanoparticle layer and a second metal nanoparticle layer having a lower density of the metal nanoparticles surrounded by the second ligand and the metal nanoparticles surrounded by the third ligand.

The autonomous judgment pressure sensor according to an embodiment of the present invention may sense pain and tactile sensations.

More specifically, the autonomous judgment pressure sensor according to an embodiment of the present invention is a pressure sensor that imitates the interrelationship between human pain and tactile sensation. In , only tactile responses can be transmitted to the brain because large-diameter tactile nerves react more strongly than pain nerves (small diameter).

On the other hand, above the critical pressure, nociceptive nerves respond more strongly than tactile nerves, so that nociception can be transmitted to the brain.

Therefore, the sensor called human skin can measure the level of pressure by itself, determine whether it is tactile or nociceptive, and then transmit information to the brain.

In the autonomous judgment pressure sensor according to an embodiment of the present invention, since the sensing unit has a heterogeneous structure including a conductive layer 161 and a semi-insulating layer 162, a tactile sense can be sensed at a pressure below a specific pressure, Above a certain pressure, pain can be detected.

In addition, just as the threshold pressure to feel pain is different for each person, the autonomous judgment pressure sensor according to an embodiment of the present invention uses the adhesion layer to selectively remove metal nanoparticles surrounded by the first ligand, which is applied to the adhesion layer. By adjusting the pressure, it is possible to control the critical pressure at which pain is felt by adjusting the range and density in which the metal nanoparticles surrounded by the first ligand are removed.

The autonomous pressure sensor according to an embodiment of the present invention uses a second ligand-substituted metal nanoparticle (eg, a metal nanoparticle surrounded by an organic ligand having a thiol group) and a second ligand substitution (eg, halide ligand substitution) process. Thus, all metal nanoparticles surrounded by the third ligand are peeled off or partially peeled off on the protrusion, and all metal nanoparticles substituted with the third ligand are included on the concave portion, so a third ligand having greater conductivity than the first ligand (e.g. By including metal nanoparticles surrounded by halide ligands), the sensitivity of the pressure sensor can be improved.

The autonomous pressure sensor according to the embodiment of the present invention has a large electrical conductivity difference on the substrate 110 having irregularities (including concavities and protrusions) using the peeling phenomenon through the adhesion layer and the second ligand substitution process. I can form two regions (conductive layer and semi-insulating layer).

The first region is present in the protrusion of the substrate 110 , and this region contains metal nanoparticles (eg, metal nanoparticles surrounded by halide ligands) surrounded by a third ligand at a low density, or a metal surrounded by a third ligand. It may be a region that does not include nanoparticles (eg, metal nanoparticles surrounded by halide ligands).

The second region is present in the concave portion of the substrate 110 , and this region may be a region including metal nanoparticles surrounded by a third ligand (eg, metal nanoparticles surrounded by halide ligands) at a high density.

The autonomous pressure sensor according to the embodiment of the present invention uses the peeling phenomenon through the second ligand substitution process, but since all the metal nanoparticles surrounded by the first ligand on the concave portion, which is the first region, are not peeled off, the first region may have semi-insulating properties.

In the autonomous pressure sensor according to an embodiment of the present invention, the closing area of the semi-insulating layer 162 formed on the concave and protruding portions of the electrode 170 and the substrate 110 may be increased according to pressure.

That is, when a first pressure P1 of a low pressure is applied to the electrode, only a portion of the semi-insulating layer 162 is in contact with the electrode and exhibits a low current value, but is higher than the first pressure P1 on the electrode 170 . When the second pressure P2, which is a critical pressure, is applied, all of the semi-insulating layer comes into contact with the electrode, so that the sensor sensitivity is rapidly changed and the power (current) value is rapidly increased, and the third pressure ( When P3) is applied, both the semi-insulating 162 layer and the conductive layer 161 may be in contact with the electrode to exhibit a high current value.

More specifically, another electrode may be formed on the substrate 110 , and thus, a sensing unit 162 connecting two electrodes 170 that are different (physically separated) from each other may be initially formed.

Hereinafter, an electrode formed on the substrate will be referred to as a second electrode, and an electrode disposed to face the substrate will be referred to as a first electrode.

A current flows from the first electrode 170 to the second electrode through the semi-insulating layer 162, and as the pressure increases, the contact area between the semi-insulating layer 162 and the first electrode 170 increases, so that the current can flow better. However, since the semi-insulating layer 162 has semi-insulating properties, it can be seen that the increase in current does not change significantly (P1).

In P1, when the pressure near the removal of the metal nanoparticles surrounded by the first ligand is reached, the conductive layer 161 of the concave portion and the first electrode 170 come into contact with each other due to the heterogeneous structure, and at this time, the conductive layer 161 Due to the low resistance of , the current value can be increased rapidly.

If the pressure is further increased after the P2 state, the current value is further increased as the contact area between the conductive layer 161 and the first electrode 170 is increased, and the increase may be 100 to 1000 times greater than that in the P1 state. .

The y-axis of the P3 state has a log scale (1og scale).

Accordingly, the autonomous pressure sensor according to an embodiment of the present invention can detect a tactile sensation at a pressure below the critical pressure of the second pressure P2, and detect pain at a pressure above the critical pressure of the second pressure P2. .

In addition, the autonomous pressure sensor according to the embodiment of the present invention removes all or only a small portion of the metal nanoparticles surrounded by the first ligand on the protrusion of the substrate 110 using an adhesive layer, so that a semi-insulating layer with high insulation properties Since the 162 is formed, when no pressure is applied, the highly insulating semi-insulating layer 162, not the conductive layer 161, is in contact with the electrode, so that a high-efficiency pressure sensor with low power consumption can be provided. .

[Example 1]: Ag nanoparticles

A synthesis solution was prepared by mixing 0.9 g of silver nitrate (AgNO3), 22.5 mL of oleic acid, and 2.5 mL of oleylamine, and the prepared synthesis solution was degassed at 70°C for 2 hours, After increasing the temperature to 180°C at a temperature increase rate of 1°C·in ⁻¹ , it was cooled to synthesize silver nanoparticles including the first organic ligand.

The washing process of washing silver nanoparticles containing the first organic ligand by centrifugation with toluene and ethanol at 5000 rpm for 5 minutes was repeated three times to disperse the silver nanoparticles containing the first organic ligand precipitated in octane 200 A silver nanoparticle solution including the first organic ligand having a concentration of mg·mL ^-1 was prepared.

A silver nanoparticle solution containing the first organic ligand was spin-coated on an APTES-treated patterned polydimethylsiloxane (PDMS) substrate at 1000 rpm to form a silver nanoparticle thin film, followed by methanol EDT (0.02 vol/vol%) and Ligand substitution treatment was performed using a ligand substitution solution containing NH ₄ Cl (10 mM).

At this time, all ligand substitution treatments were performed by adjusting the process time to 60 seconds.

[Example 2]: ITO nanoparticles

Example) 1.313 g of indium acetate (In(Ac) ³ ), 0.118 g of tin acetate (Sn(Ac) ² ), 3.425 g of Myristic acid and 100 mL of octadecine (1-Octadecene) A synthesis solution was prepared by mixing, and the prepared synthesis solution was degassed at 110° C. for 2 hours, and then the temperature was increased to 295° C., and then 5 mL of oleylamine and 5 mL of octadecine (1-Octadecene) were added. Add the mixed solution quickly. After heat treatment at 280°C for 1 hour, heat treatment at 240°C for one hour, then cool to room temperature.

The washing process of washing the indium tin nanoparticles containing the first organic ligand by centrifugation with chloroform and acetone at 8000 rpm for 3 minutes was repeated three times to disperse the precipitated indium tin nanoparticles containing the first organic ligand in octane to prepare a silver nanoparticle solution containing the first organic ligand having a concentration of 200 mg·mL-1.

At this time, all processes for manufacturing the pressure sensor are the same as in [Example 1] except that ITO was used.

6 is scanning electrons when the metal nanoparticles surrounded by the first ligand are selectively removed after applying a pressure of 250 Pa after attaching the adhesion layer when manufacturing the autonomous pressure sensor according to Example 1 of the present invention; FIG. A microscope image and an Energy Dispersive Spectroscopy-Mapping (EDS-Mapping, Energy Dispersive Spectroscopy-Mapping) image, and FIG. 7 is a scan when the metal nanoparticles surrounded by the first ligand are selectively removed after applying a pressure of 2500 Pa Electron microscopy images and energy dispersive spectral-mapped images.

Referring to FIGS. 6 and 7 , metal nanoparticles (acting as an adhesive layer) surrounded by the first ligand do not exist in the protrusion (region within the dotted line), so the protrusion is caused by a strong aggregation effect due to the second ligand substitution (halide ligand substitution) process. It can be seen that the metal nanoparticles surrounded by the first ligand formed therein are removed to expose the surface of the PDMS substrate, so that the silicon (Si) element is strongly observed in the dotted line.

Accordingly, it can be seen that silver (Ag) and chlorine (Cl) are not observed on the protrusion (region within the dotted line).

In addition, FIG. 6 shows that after applying a removal pressure of 250 Pa, metal nanoparticles surrounded by a first ligand are selectively removed, and FIG. 7 is a metal nanoparticle surrounded by a first ligand after applying a removal pressure of 2500 Pa. It can be seen that the area of the protrusion in FIG. 7 is wider than in FIG. 6 due to the greater pressure in FIG. 7 because of the selective removal.

8 is a graph showing the change in current when a pressure of 250 Pa is applied to the autonomous judgment pressure sensor according to Example 1 of the present invention, and FIG. 9 is a graph showing the change in current when a pressure of 1000 Pa is applied. and FIG. 10 is a graph showing a change in current when a pressure of 2500 Pa is applied.

8 to 10 , the autonomous judgment pressure sensor according to Example 1 of the present invention applies pressures of 250 Pa, 1000 Pa, and 2500 Pa, respectively, in the vicinity of the pressures of 250 Pa, 1000 Pa and 2500 Pa. As the current value rapidly increases, it can be seen that the pressure sensor works well.

In the initial off state (250 Pa), the contact between the two electrodes is not good, so it has a very low off current value, but enters the second state (tactile sense) as a low pressure of 1000 Pa is applied. Therefore, it can be seen that the current value increases with a constant slope as the pressure increases.

When a pressure of 2500 Pa is applied, the conductive layer comes into contact with the electrode and the current value rapidly increases, and it can be seen that the current value increases linearly by the conductive layer,

Accordingly, it can be seen that the autonomous judgment pressure sensor according to Embodiment 1 of the present invention has two inclination values due to the heterogeneous structure formed of the conductive layer and the semi-insulating layer.

More specifically, as the threshold pressure at which pain is felt is different for each person, in the manufacturing method of the autonomous judgment pressure sensor according to the embodiment of the present invention, by adjusting the removal pressure for removing the metal nanoparticles surrounded by the first ligand, Sensors tailored to individual threshold pressures can be manufactured.

Referring to FIG. 8 , the tactile pressure can be measured by the semi-insulating layer at a pressure below the threshold pressure of 250 Pa or less, and in this region, 10 at 0.01 V due to the high resistivity of the semi-insulating layer. It can represent a current value of about ^-8 . When the threshold pressure is reached, the conductive layer and the electrode come into contact, and the current value increases up to 10 ^-6 , and this region represents that a person feels pain. Just as humans are more sensitive to nociception than to touch, the sensitivity as a sensor in the nociceptive domain can be 100 times higher than that in the tactile domain.

Referring to FIG. 9 , the tactile pressure can be measured by the semi-insulating layer at a pressure below the threshold pressure of 1000 Pa or less, and in this region, 10 at 0.01 V due to the high resistivity of the semi-insulating layer. It can represent a current value of about ⁹ to 10 ⁸ . When the threshold pressure (1000 Pa) is reached, the conductive layer and the electrode meet and the current value increases up to 10 ⁶ . Similarly, the sensitivity as a sensor in the nociceptive region may be 100 times higher than that in the tactile region.

Referring to FIG. 10, at a pressure below the threshold pressure of 2500 Pa or less, the tactile pressure can be measured by the semi-insulating layer, and in this region, due to the high resistivity of the semi-insulating layer, 10 ^- It can represent a current value of about ⁸ to 10 ^-7 . When the threshold pressure (2500 Pa) is reached, the conductive layer and the electrode come into contact and the current value increases to 10 ^-5 . Similarly, the sensitivity as a sensor in the nociceptive region can be 100 times higher than that in the tactile region.

11 is a graph illustrating a relative current change ((I _on -I _off )/I _off ) when a pressure of 250 Pa is applied to the autonomous judgment pressure sensor according to Example 1 of the present invention, and FIG. 12 is 1000 It is a graph showing the relative current change ((I _on -I _off )/I _off ) when a pressure of Pa is applied, and FIG. 13 is a relative current change when a pressure of 2500 Pa is applied ((I _on -I _off ) /I _off ) is a graph showing.

11 to 13 are graphs obtained by rewriting each of the graphs of FIGS. 8 to 10 by measuring a change rate with respect to an off current.

The performance of the pressure sensor is determined by how much the current value increases when pressure is applied compared to the existing off-state current.

11 to 13 , in the autonomous judgment pressure sensor according to Example 1 of the present invention, when a pressure of 250 Pa, 1000 Pa, and 2500 Pa is applied, the current value rapidly increases, and the sensing sensitivity is excellent. it can be seen that

14 is a graph illustrating a relative current change (Normalized (I _on -I _off )/I _off ) according to the pressure of the autonomous judgment pressure sensor according to Embodiment 1 of the present invention.

Referring to FIG. 14 , it can be seen that the autonomous judgment pressure sensor according to Example 1 of the present invention has excellent sensing sensitivity as the current value rapidly increases when pressures of 250 Pa, 1000 Pa, and 2500 Pa are applied, respectively. have.

15 is a graph showing the change in current according to the pressure of the autonomous judgment pressure sensor according to Example 2 of the present invention manufactured using ITO nanoparticles.

Referring to FIG. 15 , it can be seen that the autonomous judgment pressure sensor according to Embodiment 2 of the present invention has two inclination values due to the heterogeneous structure formed of the conductive layer and the semi-insulating layer.

16 and 17 are images illustrating sensing results according to pressure of the autonomous judgment pressure sensor according to Embodiment 2 of the present invention.

16 and 17 show the results of sensing the pressure by placing an object on the pressure sensor after manufacturing the autonomous judgment pressure sensor according to the second embodiment of the present invention with a large area like a chessboard in 6 rows.

16 and 17 , when an object is positioned on the autonomous judgment pressure sensor according to Embodiment 2 of the present invention, it can be seen that the pressure accurately measures the position.

As described above, although the present invention has been described with reference to limited embodiments and drawings, the present invention is not limited to the above embodiments, and various modifications and variations from these descriptions are provided by those skilled in the art to which the present invention pertains. This is possible. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined by the following claims as well as the claims and equivalents.

10, 110: substrate 20: sensing unit
30: electrode 111: concave
112: protrusions 120, 121: metal nanoparticles surrounded by a first ligand
130: adhesion layer 140: metal nanoparticles surrounded by a second ligand
150: metal nanoparticles surrounded by a third ligand
161: conductive layer 162: semi-insulating layer
130: adhesion layer 140: metal nanoparticles surrounded by a second ligand

Claims (15)

manufacturing a substrate including concave portions and protrusions;
coating the metal nanoparticles surrounded by the first ligand on the concave and protruding portions of the substrate;
forming a sensing unit by performing a ligand substitution process using metal nanoparticles surrounded by the first ligand; and
disposing an electrode to face the substrate;
The sensing unit includes a conductive layer formed on the concave portion of the substrate and a semi-insulating layer formed on the protrusion of the substrate. Way.
According to claim 1,
The step of forming the sensing unit by performing a ligand substitution process using the metal nanoparticles surrounded by the first ligand,
selectively removing the metal nanoparticles surrounded by the first ligand formed on the protrusion using an adhesion layer;
forming a first metal nanoparticle layer including metal nanoparticles surrounded by a second ligand by substituting the first ligand through a first ligand substitution process;
coating the metal nanoparticles surrounded by the first ligand on the substrate on which the first metal nanoparticle layer is formed; and
forming a second metal nanoparticle layer including metal nanoparticles surrounded by a third ligand by substituting the first ligand through a second ligand substitution process;
A method of manufacturing an autonomous judgment pressure sensor comprising a.
3. The method of claim 2,
The second ligand substitution process is
A method of manufacturing an autonomous judgment pressure sensor, characterized in that the resistance of the metal nanoparticles surrounded by the third ligand is adjusted according to the presence or absence of the metal nanoparticles surrounded by the second ligand.
3. The method of claim 2,
The third ligand is a method of manufacturing an autonomous judgment pressure sensor, characterized in that the length is shorter than that of the first ligand and the second ligand.
3. The method of claim 2,
The method of manufacturing an autonomous judgment pressure sensor, characterized in that the first ligand and the second ligand include an organic ligand, and the third ligand is surrounded by an inorganic ligand.
3. The method of claim 2,
The step of selectively removing the metal nanoparticles surrounded by the first ligand formed on the protrusion using the adhesion layer,
The method of manufacturing an autonomous judgment pressure sensor, characterized in that 80% to 99% of the metal nanoparticles surrounded by the first ligand formed on the protrusion by the adhesion layer are removed.
3. The method of claim 2,
The method of manufacturing an autonomous judgment pressure sensor, characterized in that the semi-insulating layer has a lower density of metal nanoparticles surrounded by a second ligand and metal nanoparticles surrounded by a third ligand than the conductive layer.
According to claim 1,
The method for manufacturing an autonomous judgment pressure sensor, wherein the semi-insulating layer is thinner than the conductive layer.
According to claim 1,
The method for manufacturing an autonomous judgment pressure sensor, characterized in that the width of the protrusion of the substrate is 10 μm to 10 mm.
According to claim 1,
The method of manufacturing an autonomous judgment pressure sensor, characterized in that the height of the protrusion of the substrate is 5 μm to 5 mm.
a substrate including recesses and protrusions;
a sensing unit formed on the concave and protruding portions of the substrate; and
an electrode disposed to face the substrate;
and the sensing unit includes a conductive layer formed on the concave portion of the substrate and a semi-insulating layer formed on the protrusion of the substrate.
12. The method of claim 11,
wherein the conductive layer includes a first metal nanoparticle layer including metal nanoparticles surrounded by a second ligand and a second metal nanoparticle layer including metal nanoparticles surrounded by a third ligand.
12. The method of claim 11,
The semi-insulating layer comprises a first metal nanoparticle layer including metal nanoparticles surrounded by a second ligand and a second metal nanoparticle layer including metal nanoparticles surrounded by a third ligand. sensor.
14. The method of claim 13,
The semi-insulating layer has a lower density of metal nanoparticles surrounded by a second ligand and metal nanoparticles surrounded by a third ligand than the conductive layer.
12. The method of claim 11,
The autonomous judgment pressure sensor is an autonomous judgment pressure sensor, characterized in that it detects pain and tactile sensation.

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