JP2010222465A - Array of autonomously responding gel, autonomously responding material, autonomously responding device, autonomously responding method and method for producing array of autonomously responding gel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an array of an autonomously responding gel autonomously responding by external stimulation, an autonomously responding material and a method for producing the array of the autonomously responding gel, and to provide an autonomously responding device to control autonomous response of the array of the autonomously responding gel by electric potential and an autonomously responding method. <P>SOLUTION: The array of the autonomously responding gel has a plurality of protrusions formed of the autonomously responding gel and having a diameter of 1-1,000 μm and an axial height of 20-400 μm and an autonomously responding gel layer formed of the autonomously responding gel same as the material of the protrusions and connected with the protrusion at a part of the axial direction of the protrusion. The autonomously responding material contains a reaction substrate filled in spaces of the autonomously responding gel array. The array of the autonomously responding gel is produced by ultraviolet irradiation through a photomask. The autonomous response of the autonomously responding material is controlled by application of electric potential to the autonomously responding gel. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an array of autonomous responsive gel, an autonomous responder, an autonomous response device, an autonomous response method, and a method of manufacturing an array of autonomous responsive gel.

Since the characteristics of a substance are determined by the thermodynamically stable structure (periodic structure such as a crystal structure) of the constituent elements, a new function of the substance can be expected to appear by adding an artificial regular structure. Superlattice films and ordered structures are examples of this, and various materials creation studies are being conducted.
On the other hand, biological functions are known to express various functions due to their hierarchical internal structure, and have an intelligent function to change the internal structure by response to stimuli, which is not in the artificial rule structure. ing.

  Here, a cellular automaton (hereinafter sometimes referred to as “CA”) proposed as a universal computer concept is considered to be one of the principles for artificially expressing such stimulus responsiveness, but is still complicated. It is only used for simulation of system phenomena.

  On the other hand, Turing predicted that various pattern formation principles existing in nature are based on the reaction diffusion system principle (hereinafter sometimes referred to as “RD principle”). In reaction-diffusion systems, the usefulness of this method as an artificial pattern formation principle is being experimentally verified.

  The CA and RD principle is based on the function of an artificial micro basic constituent element as in the superlattice film and the ordered arrangement structure. However, the major difference is that the simple interaction of adjacent micro-elements results in patterning that is much larger than the micro-element size scale, or hierarchical patterning. It exists in the point which can form a spatial pattern. This is one typical mechanism for linking the functions of microelements to macro functions, and many biological functions are used. Therefore, the CA and RD principles may be able to provide “intelligentity in which the macro function changes and responds to local stimulation”, which is not found in conventional material creation methods.

Here, the cellular automaton (CA) is a mathematical model that predicts collective phenomena, nonlinear phenomena, and non-equilibrium phenomena by determining only the interaction between adjacent elements. In the field of computational science, it has already been used for forest fires, simulation of traffic jams, and prediction of heavy oil spill distribution.
For example, (1) having uniform cells of the same size, (2) the cells are composed of a finite number, and (3) depending on the state of a certain cell at time t, the specific cell at time t + 1 By giving information that the state of a cell adjacent to the cell is determined, a cellular automaton that exhibits a desired spatiotemporal pattern is realized.

  Examples of applications that use the CA principle include “energy filters” that can variably control the flow of heat, light, ions, etc., and “artificial flagella” that can transport materials by the expansion and contraction of an autonomous gel. The creation of devices is expected. The technology that can variably control the heat flow is considered an important technology in the utilization of waste heat. Advantages of this cellular automaton energy filter include (1) the ability to control the flow of macro energy by partial stimulation, and (2) the ability to convert from direct current to alternating current using an autonomous response phenomenon. Express macro function.

The above-described CA type functional material whose macro function (hierarchical structure) dynamically changes in response to an external stimulus can be roughly divided into the following three elements.
(1) Formation of a regular array composed of cells of the same size.
(2) Giving the cell a switch function for stimulation.
(3) Addition of a function for causing the cells to interact with each other.

Here, a gel containing a Ru complex has been proposed as an autonomously responsive gel having a switch function for stimulation (see, for example, Non-Patent Document 1).
This gel uses the Belousov-Zhabotinsky (BZ) reaction), and is a gel that oscillates forward and backward in an autonomous and periodic manner. The ruthenium complex (Ru (bpy) ₃ ) periodically undergoes redox changes in the BZ reaction solution, and the valence changes periodically between divalent and trivalent. The oxidation state (trivalent) of the Ru complex indicates hydrophilicity, and the reduced state (divalent) indicates hydrophobicity. Since the polymer gel described in Non-Patent Document 1 is a temperature-responsive polymer, the phase transition temperature changes due to the change in the redox state of the Ru complex, and as a result, it expands and contracts in the forward and backward directions.

In addition, as a method for producing an ordered array of autonomously responsive gels, a three-dimensional micromachining method using X-rays or the like is applied, and the gel is processed to a size of about several hundred μm (for example, the above-mentioned non-reactive gel). Patent Document 1).
As another manufacturing method, a method for manufacturing an ordered array using pores of anodized porous alumina has been proposed (see, for example, Patent Document 1).

JP 2006-62049 A

Takaaki Sakai, Ryo Yoshida “Fabrication of spatio-temporal functional surfaces using self-excited vibrating gels” Surface Science Vol.28, No.11, p.

  As described above, several methods for forming a regular array have been proposed, but a method for effectively interacting cells is not disclosed.

Then, the subject of this invention is providing the manufacturing method of the array of the autonomous responsive gel which responds autonomously by an external stimulus, the autonomous responder, and the array of the autonomous responsive gel.
Moreover, the subject of this invention is providing the autonomous response apparatus and autonomous response method which control the autonomous response of the array of an autonomous response gel by an electric potential.

The invention according to claim 1
A plurality of protrusions having a diameter of 1 μm to 1000 μm and an axial height of 20 μm to 400 μm formed of an autonomously responsive gel;
An autonomous responsive gel layer composed of an autonomously responsive gel of the same quality as that of the protrusion, connected at a part in the axial direction of the protrusion,
An array of autonomously responsive gels having

The invention according to claim 2
2. The autonomously responsive gel array according to claim 1, wherein the thickness of the autonomously responsive gel layer is 1% or more and 30% or less with respect to the axial length of the protrusion.

The invention according to claim 3
The autonomously responsive gel according to claim 1 or 2, wherein the autonomously responsive gel is stimuli responsive.

The invention according to claim 4
The autonomously responsive gel is
N-isopropylacrylamide,
A monomer having a ruthenium complex, a cerium complex, a manganese complex, or an iron-phenanthroline complex, which is a catalyst for the Belousov-Zhabotinsky reaction,
It is the array of the autonomous responsive gel of any one of Claims 1-3 which has the structural unit derived from.

The invention according to claim 5
5. The autonomously responsive gel array according to claim 4, wherein the monomer having a ruthenium complex is a compound represented by the following chemical formula (1).

The invention according to claim 6
The array of autonomously responsive gels according to any one of claims 1 to 5,
A reaction substrate for transmitting reaction diffusion, filled in a gap between the arrays;
Is an autonomous responder having

The invention according to claim 7 provides:
The autonomous responder according to claim 6, wherein the reaction substrate is a mixed solution containing an organic acid, an inorganic acid, and an oxidizing agent.

The invention according to claim 8 provides:
The array of autonomously responsive gels according to any one of claims 1 to 5,
A reaction substrate for transmitting reaction diffusion, filled in a gap between the arrays;
An electrode connected to a part of the array;
An electrode in contact with the reaction substrate;
A voltage applying device for applying a voltage to the electrode;
Is an autonomous response device of an autonomous response body having

The invention according to claim 9 is:
It is an autonomous response method of the autonomous responder which applies the voltage of -0.5V--2.0V to the autonomous responder of Claim 6 or Claim 7.

The invention according to claim 10 is:
In the solution containing the precursor of the self-responsive gel,
Irradiate ultraviolet rays through a photomask,
It is a manufacturing method of the array of the autonomous responsive gel of any one of Claims 1-5.

The invention according to claim 11 is:
The method for producing an array of autonomously responsive gels according to claim 10, wherein ultraviolet rays having an irradiation intensity of 10 mW / cm ² or more and 5000 mW / cm ² or less are irradiated for 50 seconds or more and 10,000 seconds or less.

The invention according to claim 12
It is a manufacturing method of the array of the autonomous response gel of Claim 10 or Claim 11 which irradiates the said ultraviolet-ray with the irradiation amount satisfy | filling following formula (1).
100000 ≧ irradiation intensity (mW / cm ² ) × irradiation time (seconds) ≧ 500 Formula (1)

ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the array of the autonomous responsive gel which responds autonomously by an external stimulus, the autonomous responder, and the array of the autonomous responsive gel can be provided.
Moreover, according to this invention, the autonomous response apparatus and autonomous response method which control the autonomous response of the array of an autonomous response gel by an electric potential can be provided.

It is a schematic cross section showing an example of the autonomous responder of the present invention. It is a schematic diagram explaining the preparation methods of the array of an autonomous responsive gel. It is a figure which shows an example of the voltage application method which makes an autonomous responsive gel respond autonomously. It is a schematic diagram which shows an example of the autonomous response apparatus of this invention. 2 is an electron micrograph of a cross section of the autonomously responsive gel array obtained in Example 1. FIG. It is a photograph which shows a mode that the autonomous-responsive gel arrangement | sequence obtained in Example 1 responds autonomously by voltage application. (A) is a photograph showing a state two minutes after voltage application, and (B) is a photograph showing a state five minutes after voltage application. It is a figure for demonstrating the photograph of FIG. 7A and 7B correspond to FIGS. 6A and 6B, respectively.

  Hereinafter, an example of an embodiment of the present invention will be described with reference to the drawings. Note that components having substantially the same functions are described with the same reference numerals throughout the drawings, and description thereof may be omitted in some cases.

<Autonomous Responsive Gel Array and Autonomous Responder>
The array of autonomously responsive gels of the present invention is connected to a plurality of protrusions formed from the autonomously responsive gel and having a diameter of 1 μm to 1000 μm and an axial height of 20 μm to 400 μm, and a part of the protrusions in the axial direction. An autonomously responsive gel layer composed of an autonomously responsive gel of the same quality as the protrusions.
The autonomous responder of the present invention includes an array of the autonomously responsive gel and a reaction substrate that transmits reaction diffusion and is filled in a gap between the array.

Here, first, a method for interacting each cell of a regular array, which has been considered in principle, will be described.
In the BZ reaction which is one of the autonomous responses, according to the two-variable Oregonator model of the following formulas (1) and (2) proposed by P. Foerster et al. And the following formulas (3) and (4) obtained from experiments ( P. Foerster, SCMuller, B. Hess, Proc. Natl. Acad. Sci. USA, Vol. 86, p6831-6834 (1989), P. Foerster, J. Phys. Chem., Vol. 94, Issue. 26, p8859-8861 (1990)), by adjusting the plane wave velocity c and the diffusion coefficient D according to the size (diameter) of the autonomously responsive gel, the chemical propagation wave is propagated between the aligned autonomous responder gels. be able to.

In the above formulas (1) and (2), two variables (u, v) represent the concentrations of [HBrO ₂ ] and [catalyst: Ru ²⁺ ], respectively. D represents a diffusion coefficient, and f, ε, and g are parameters corresponding to an excitability (= oxidation) threshold, excitability, and reaction rate constant, respectively.

The above equation (3) represents the relationship between the curvature (K) of the propagation wave of the spatiotemporal pattern due to the BZ reaction, the velocity (N) of the curved wavefront, the plane wave velocity (c), and the diffusion constant (D). The threshold radius (R _crit ) at which no _occurrence occurs is estimated from equation (4). In this experiment, two silver electrodes (gap 4 mm, diameter 100 mm) were immersed to limit the reaction region, and K, N, c, and D of the spatiotemporal pattern in the BZ solution were _subjected to image analysis, and R _crit was estimated. ing.

Here, as derived from the above equation (4), the minimum radius R _crit of the chemical propagation wave can be changed by adjusting the diffusion coefficient D and the plane wave velocity c. The reduction of the diffusion coefficient D can be realized by increasing the viscosity of the reaction substrate solution filled in the array of autonomously responsive gels or by solidifying it.
That is, when the viscosity of the reaction substrate solution is adjusted so that the minimum radius R _crit of the chemical propagation wave corresponding to the size of each cell of the autonomous responsive gel is adjusted, the chemical wave is propagated between the cells.

Thus, in order to make each cell of the arranged autonomous responsive gel interact with each other, the diffusion coefficient D and plane wave velocity c of the reaction substrate filled in the gap of the array of the autonomous responsive gel are calculated from the above formula. Therefore, complicated operations such as adjusting the viscosity of the reaction substrate solution so as to obtain the diffusion coefficient D and plane wave velocity c are necessary. Moreover, even if the viscosity of the reaction substrate solution is adjusted, there are cases where the distance of the chemical propagation wave is short or the response speed is slow.
In particular, it has been clarified that the self-excited vibration of the gel hardly occurs when the diameter of each of the arranged autonomous responsive gels is reduced to several hundred μm or less.

  On the other hand, the autonomous responder of the present invention does not adjust the plane wave velocity c and the diffusion coefficient D based on the formulas (1) to (4), and the case where the diameters of the arranged gels are small or Even when the temperature is as low as 35 ° C. or lower, chemical propagation waves can be propagated effectively.

(Autonomous responsive gel)
The “autonomous responsive gel” according to the present invention refers to a gel that determines an external stimulus, determines its reaction, and develops an autonomous response by the presence of a reaction substrate.
The autonomous responsive gel used for the array of autonomous responsive gels of the present invention exhibits autonomous responsiveness due to the presence of the reaction substrate. Here, “autonomy” refers to the property of being able to form a temporal and spatial order. Autonomously responsive gel enables an autonomous response by enclosing a periodic reaction system therein. Examples of such a periodic reaction include a Belousov-Zhabotinsky reaction (Belousov-Zhabotinsky (BZ) reaction), which shows a periodic redox reaction, and iodine (I ₂ ), chloride, which shows a periodic chemical reaction. A reaction of an oxide (ClO ₂ ) and malonic acid (CDIMA reaction) can be exemplified. Further, “responsiveness” refers to the property of responding to external stimuli such as heat and light.
Therefore, the autonomously responsive gel of the present invention has at least a part having autonomy and a part having a switch function (sensitivity) to stimulation.

  Hereinafter, a temperature-responsive polymer using the Belousov-Zhabotinsky (BZ) reaction will be described as an example of an autonomously responsive gel.

The ruthenium complex (Ru (bby) ₃ ) (hereinafter sometimes referred to as “Ru complex”), which is a catalyst for the BZ reaction, undergoes a redox reaction spontaneously and periodically with the passage of time, resulting in a trivalent oxidation state. Spontaneously and periodically between the divalent and divalent reduction states. Here, Ru complexes in the oxidation state ^{(Ru 3+)} represents a hydrophilic, Ru complex of a reduced state ^{(Ru 2+)} indicates hydrophobicity.

Therefore, the gel in which this Ru complex is introduced into a part of the temperature-responsive polymer changes in phase transition temperature due to a change in the redox state of the Ru complex. Specifically, when the Ru complex is in the oxidation state (Ru ³⁺ ), it exhibits a phase transition temperature higher than the phase transition temperature (lower critical phase transition temperature: LCST) of the original combined temperature-responsive polymer, and the reverse in the case Ru complexes of a reduced state (Ru ²⁺⁾ indicates a phase transition temperature lower than the phase transition temperature of the original temperature-responsive polymer.

  Therefore, when this gel is immersed in a BZ reaction solution (mixed solution of malonic acid, sodium bromate and nitric acid) at a constant temperature, the hydrophilicity / Hydrophobic properties change periodically, and expansion / contraction motion occurs spontaneously.

The Ru complex has a different color tone depending on the valence. It is light green in the oxidized state (Ru ³⁺ ) and orange in the reduced state (Ru ²⁺ ). Therefore, the gel having a Ru complex spontaneously and periodically changes color with time.

Since the period and amplitude of the BZ reaction depend on the concentration and temperature of the reaction substrate, the vibration rhythm and color change of the gel can be controlled by changing the concentration and temperature.
In addition, regarding the temperature-responsive self-responsive gel using the BZ reaction, Takaaki Sakai and Ryo Yoshida “Fabrication of spatio-temporal functional surfaces using self-excited vibration gel” Surface Science Vol.28, No.11, p647 ~ 652, 2007.

  Examples of the temperature-responsive gel include gels composed of N-isopropylacrylamide polymer, polyethylene glycol / polypropylene glycol copolymer, polyether, cellulose derivative, and N-substituted acrylamide derivative polymer. From the viewpoint of phase transition at a gel, a gel having a structural unit derived from N-isopropylacrylamide is preferable.

Examples of the catalyst for the BZ reaction include a cerium (Ce) complex, a manganese (Mn) complex, and an iron-phenanthroline (Fe (phen) ₃ ) complex in addition to a Ru complex, and among these, a Ru complex is preferable. .

  Therefore, a gel having at least a structural unit derived from N-isopropylacrylamide and a structural unit derived from a monomer having the Ru complex is suitable as the temperature-responsive autonomously responsive gel. The temperature-responsive self-responsive gel may include a structural unit derived from another monomer.

The monomer having the Ru complex is preferably a compound represented by the following chemical formula (1) from the viewpoint of ease of gel synthesis.

In addition, since the temperature-responsive self-responsive gel has a gel shape, it is crosslinked in at least a part of a structural unit derived from N-isopropylacrylamide.
From the above, the temperature-responsive self-responsive gel in the present invention is preferably a gel having the following structure.

  In addition, the autonomously responsive gel in the array of autonomously responsive gels of the present invention is responsive to stimuli such as light, hydrogen ion concentration (pH), voltage, potential, pressure, etc. in addition to the gel that responds to the above temperature It may be a stimulus-responsive gel. Among these, it is preferable that the gel is a temperature-responsive gel from the viewpoint of easy control of response and the viewpoint of the manufacturing method described later.

In addition to the temperature-responsive self-responsive gel shown in the above example, as described in, for example, Yusuke Hara, Mechanical Materials, February 2007, Vol. 27, No. 2, p40-p49, BZ Autonomous polymer (poly-N isopropylacrylamide-Ru (bpy) ₃ complex-AMPS) encapsulating a site (acrylamide-2-methylpropanesulfonic acid: AMPS) that creates an acidic environment indispensable for the reaction and an oxidizing agent There is also a self-responsive polymer poly-N isopropylacrylamide (Ru (bpy) ₃ complex-AMPS-MAPTAC) that encapsulates the bromine acid itself (quaternary cation methacrylamidopropyltrimethylammonium chloride: MAPTAC). Applicable.

(Construction)
The array of autonomously responsive gels of the present invention is connected to a plurality of protrusions formed from the autonomously responsive gel and having a diameter of 1 μm to 1000 μm and an axial height of 20 μm to 400 μm, and a part of the protrusions in the axial direction. An autonomously responsive gel layer composed of an autonomously responsive gel of the same quality as the protrusions. The autonomous responder of the present invention includes an array of the autonomously responsive gel and a reaction substrate that transmits reaction diffusion and is filled in a gap between the array.

FIG. 1 is a schematic cross-sectional view showing an example of the autonomous responder of the present invention.
The array 10 of the autonomously responsive gel of the present invention has a plurality of protrusions 12 formed of the autonomously responsive gel and an autonomously responsive gel layer 14 that connects the plurality of protrusions 12. The autonomously responsive gel layer 14 is provided so as to be connected to a part of the protrusion 12 in the axial direction. The position to be connected by the autonomous responsive gel layer 14 is not limited, but it is preferable that the connection is made at one end in the axial direction of the protrusion 12 when used for an application such as an actuator, or when manufacturing. Can be produced more easily.

In the autonomous responder 20 of the present invention, the reaction substrate 16 is filled in the gap of the array 10 of the autonomously responsive gel. As the reaction substrate 16, for example, when an autonomously responsive gel using a BZ reaction is used, an organic acid such as malonic acid that causes a BZ reaction, an inorganic acid such as nitric acid, and an oxidizing agent bromic acid (NaBrO ₃ ) are used. Use medium to contain. The reaction substrate 16 is added to a solvent such as water to fill the gaps in the array 10.

The protrusion 12 and the autonomously responsive gel layer 14 contain a catalyst 18 that causes an autonomously responsive reaction. For example, as the catalyst 18 in the autonomously responsive gel using the BZ reaction, a ruthenium (Ru) complex, a cerium (Ce) complex, a manganese (Mn) complex that causes a redox reaction spontaneously and periodically over time. Or an iron-phenanthroline (Fe (phen) ₃ ) complex.

  Here, the autonomous responsive gel layer 14 is composed of an autonomous responsive gel of the same quality as the protrusions 12. The term “same quality” as used herein means that the monomer units constituting the gel are the same. As described later, when a gel is prepared by polymerizing an autonomously responsive gel precursor (monomer) by ultraviolet irradiation, the protrusion 12 and the autonomously responsive gel layer 14 are prepared from the same autonomously responsive gel precursor.

  Providing an autonomously responsive gel layer 14 connected by an autonomously responsive gel of the same quality as the protrusion 12 in a part of the protrusion 12 in the axial direction makes it possible to effectively interact the plurality of protrusions 12. The reason is estimated as follows, but the present invention is not limited by the estimation.

  Since the reaction substrate 16 contained in the protrusion 12 diffuses through the autonomous responsive gel layer 14 by connecting the plurality of protrusions 12 with the autonomous responsive gel layer 14 of the same quality as the protrusion 12 (arrow in FIG. 1), The diffusion flux of the reaction substrate 16 is increased, and a relatively small external stimulus (for example, a relatively low voltage) can trigger an autonomous response phenomenon. In addition, when an external stimulus is applied to the gel array (for example, a voltage is applied by applying a potential difference between electrodes connected to the gel array), it is difficult to respond autonomously (for example, an arrayed gel Autonomous response can be induced even when the diameters of each are small or when the temperature is as low as 35 ° C. or less.

  On the other hand, when the autonomously responsive gel layer 14 does not exist between the plurality of protrusions 12 and is filled with the reaction substrate 16, diffusion resistance exists between the protrusions 12 and the reaction substrate 16. Further, unless the diffusion rate of the reaction substrate 16 existing in the gaps between the protrusions 12 is appropriately adjusted, chemical propagation waves do not propagate between the plurality of protrusions 12.

  In particular, considering that the diffusion flux of the reaction substrate and the occurrence of the response phenomenon of the plurality of protrusions 12 are controlled by voltage application, the thickness T of the autonomously responsive gel layer 14 is smaller than the length L in the axial direction. It is preferably 1% or more and 30% or less, more preferably 2% or more and 25% or less, and still more preferably 5% or more and 20% or less. For example, when the height of the protrusion 12 (the length L in the axial direction) is 50 μm, the thickness of the autonomous responsive gel layer 14 is preferably 0.5 μm or more and 15 μm or less.

  When the thickness T of the self-responsive gel layer 14 exceeds 30% with respect to the axial length L, the properties of the gel array are the properties of a gel continuous film having the axial length L as the film thickness. It shows a response phenomenon autonomously even when no voltage is applied. This phenomenon has been confirmed by experiments. Therefore, when the autonomous response (vibration) phenomenon is controlled by voltage application, it is preferable that the thickness T of the autonomously responsive gel layer 14 is within the above range.

  The thickness T of the self-responsive gel layer 14 can be adjusted by changing the irradiation time of ultraviolet irradiation in the manufacturing process described later.

  The diameter of the protrusion 12 is a micrometer size and is 1 μm to 1000 μm, preferably 10 μm to 1000 μm, and more preferably 40 μm to 1000 μm.

The axial length L of the protrusion 12 is 20 μm to 400 μm, more preferably 40 μm to 200 μm, and still more preferably 50 μm to 100 μm.
When the length L in the axial direction of the protrusion 12 is less than 20 μm, the color change in the oxidation state and reduction state of the catalyst contained in the autonomous response gel and the optical contrast become small, and the structural change (time) Observation of the autonomous responsiveness of the (space pattern) becomes difficult. On the other hand, if it exceeds 400 μm, it becomes difficult to form a gel projection pattern. Therefore, in order to suppress the autonomous response (vibration) phenomenon of the array of autonomous responsive gels, it is preferable to set the length L in the axial direction within the above range.

  The shape of the protrusion 12 is not limited, and may be any of a rod shape, a column shape, a conical shape, a polygonal pyramid shape, and the like. Further, the cross-sectional shape of the protrusion 12 is not limited, and may be any one of a circle, an ellipse, a polygon, and the like.

  The length L in the axial direction of the protrusion 12 can be adjusted by changing the depth of the precursor solution irradiated with ultraviolet rays in the manufacturing process described later. Note that the axial length L of the protrusion 12 is related to the ease of patterning of the gel precursor by ultraviolet rays. The ease of patterning means that there is a limit of separation from adjacent patterns due to light refraction or diffusion due to diffusion in the gel precursor solution during light irradiation. The ease of patterning is also affected by the polymerization sensitivity of the gel precursor to ultraviolet light. Further, the axial length L of the protrusion 12 is also adjusted by the thickness of the container portion surrounded by the seal (spacer) 32 into which the gel precursor solution 34 is injected, as shown in FIG. .

(Reaction substrate)
The autonomous responder 20 of the present invention includes a reaction substrate 16 that transmits reaction diffusion. The presence of the reaction substrate 16 causes the autonomously responsive gel to respond autonomously.
When an autonomously responsive gel using the BZ reaction is used as the reaction substrate 16 for transmitting the reaction diffusion, an organic acid such as malonic acid that causes the BZ reaction, an inorganic acid such as nitric acid, an oxidizing agent bromic acid (NaBrO) ₃ ) The medium containing is used.

  The autonomous responder 20 of the present invention can effectively propagate a chemical propagation wave without adjusting the plane wave velocity c and the diffusion coefficient D based on the above-described formulas (1) to (4). it can. Therefore, in order to adjust the diffusion coefficient D in the above formula (4), it is not particularly necessary to adjust the gelation or the viscosity by adding a gelling agent or a thickening agent to the reaction substrate 16. Adjustments can be made. As the gelling agent, known ones can be appropriately selected and used. A known thickener can be appropriately selected and used.

<Method for producing array of autonomous responsive gel>
Next, the manufacturing method of the array 10 of an autonomous responsive gel is demonstrated.
The method for producing an autonomously responsive gel array 10 of the present invention includes a step of irradiating a solution containing a precursor of an autonomously responsive gel with ultraviolet rays through a photomask. Other steps may be included.

  In the present invention, since the above-mentioned autonomously responsive gel is used, it varies spontaneously and periodically with respect to external stimuli such as light and heat. Therefore, it is not always possible to divert a general polymer production method as it is.

  Here, the array of autonomously responsive gels is a structure that is regularly arranged in consideration of application to cellular automata. As a result of various investigations on a method for producing an array of autonomously responsive gels in which chemical propagation efficiently occurs, it was preferable to produce arrays by irradiating with ultraviolet rays through a photomask.

One method for producing an array of autonomously responsive gels in Patent Document 1 described above is to prepare a polymer, dissolve the polymer in a solvent, fill the pores of anodized alumina, It is a method of evaporating.
However, in the case of a gel-like substance such as an autonomously responsive gel, it is extremely difficult to fill the pores with the above method. It is also extremely difficult to select an appropriate solvent that dissolves the autonomously responsive gel itself.
Further, in the method using the pores of the anodized alumina as the gel template, it is difficult to provide the autonomously responsive gel layer 14 that connects the plurality of autonomously responsive gel protrusions 12.

  As another method for producing an array of autonomous responsive gels, there is a three-dimensional micromachining (LIGA) using X-rays as described in Non-Patent Document 1 above. However, even with this method, it is difficult to provide the autonomously responsive gel layer 14 that connects the plurality of protrusions 12 formed of the autonomously responsive gel. Moreover, it is very difficult to produce an array of gels by X-ray processing (LIGA), and the production efficiency is low. Furthermore, the processing accuracy has a minimum size of about 200 μm, and a gel array smaller than this is not formed.

  As described above, in the conventional method for producing an array of autonomous responsive gels, there is no actual situation in which the autonomous responsive gel layer 14 is provided. Further, the operation is complicated and the production efficiency is low.

  In contrast, the method for producing an array of autonomously responsive gels according to the present invention is a method of irradiating a solution containing a precursor of an autonomously responsive gel with ultraviolet rays through a photomask.

  In FIG. 2, the schematic diagram explaining the preparation methods of the array of the autonomous response gel which concerns on this invention is shown. A frame is prepared on the glass substrate 30 by a heat seal 32, and the precursor solution 34 is injected into the frame. In this state, ultraviolet rays are irradiated through the photomask 36 to polymerize the precursor.

  In the method for producing an array of autonomously responsive gels according to the present invention, in addition to being able to form the autonomously responsive gel layer 14, fine protrusions 12 can be produced, the operation is simple, and the production efficiency is high.

Although the reason why the autonomously responsive gel layer 14 is formed by the manufacturing method of the present invention is not clear, the following reason is presumed. However, the present invention is not limited for these reasons.
The formation of the autonomously responsive gel layer 14 is shielded by the photomask when ultraviolet rays wrap around the masked portion of the photomask or when the temperature of the solution containing the precursor of the autonomously responsive gel is increased by irradiation. It is speculated that the polymerization reaction may proceed even in the portion.
Hereinafter, the manufacturing method of the array of autonomous responsive gel is demonstrated for every process.

(Preparation of precursor solution)
A solution containing a precursor of an autonomously responsive gel (hereinafter may be referred to as “precursor solution”) is prepared. The precursor solution contains at least a precursor of an autonomously responsive gel, a polymerization initiator, and a crosslinking agent. Further, the precursor solution may contain a solvent and the like.

  The precursor of an autonomously responsive gel is a monomer or oligomer for forming an autonomously responsive gel, and includes at least a site for imparting autonomy and a site for imparting a switch function (sensitivity) to a stimulus. Including.

As described above, the monomer for imparting autonomy to the gel is preferably a monomer having the Ru complex, and more preferably a compound represented by the chemical formula (1).
Further, as a monomer for imparting sensitivity to the gel, N-isopropylacrylamide capable of obtaining a temperature-responsive gel is preferable.
Further, other monomers may be added to the precursor solution.

  The content (concentration) of the precursor of the autonomously responsive gel in the precursor solution is preferably 0.1% by mass or more and 100% by mass or less from the viewpoint of workability and degree of polymerization. More preferably, it is at most 16 mass%, more preferably at least 16 mass% but at most 20 mass%.

  A known polymerization initiator can be applied to the precursor solution, and examples thereof include organic peroxides. Examples of the organic peroxide include cumene hydroperoxide, tertiary butyl hydroperoxide, dichloroperoxide, ditertiary butyl peroxide, benzoyl peroxide, acetyl peroxide, lauroyl peroxide, 2,2-dimethoxy-1,2 -Diphenylethane-1-one, 2,2-dimethoxy-2-phenylacetophenone, etc. are mentioned.

  The photopolymerization initiator preferably has a maximum absorption wavelength of 450 nm or less, and more preferably 360 nm or less. Thus, by setting the absorption wavelength to the ultraviolet region, the precursor solution before irradiation can be handled under white light.

  Examples of commercially available photopolymerization initiators include Irgacure 651, Irgacure 184, Irgacure 127, and Irgacure 907 manufactured by Ciba Special Chemicals.

  As a photoinitiator in this invention, only 1 type may be used and 2 or more types may be used together.

  The content of the photopolymerization initiator is 0.1% by mass or more and 100% by mass or less with respect to the total amount of the precursor of the autonomous responsive gel (total amount of polymerization initiator / autonomous responsive gel precursor). Is preferably 10% by mass or more and 80% by mass or less, and more preferably 30% by mass or more and 40% by mass or less.

A known crosslinking agent can be applied to the precursor solution, such as N, N′-methylenebisacrylamide (MBAAm), N-succinimidylacrylic acid, acrylamide-2-methylpropanesulfonic acid (AMPS). Etc.
As a crosslinking agent in this invention, only 1 type may be used and 2 or more types may be used together.

  The content of the crosslinking agent is preferably 10% by mass or more and 30% by mass or less with respect to the total amount of the precursor of the autonomously responsive gel (total amount of the precursor of the crosslinking agent / autonomously responsive gel).

  The solvent used in the precursor solution is not particularly limited as long as it dissolves the autonomously responsive gel precursor. Examples include ethanol, methanol, dimethyl sulfoxide (DMSO), and the like.

(UV irradiation)
A frame is prepared on the glass substrate 30 by a heat seal 32, and the precursor solution 34 is injected into the frame. In this state, ultraviolet rays are irradiated through the photomask 36 to polymerize the precursor.
For the irradiation for polymerization, ultraviolet rays having a wavelength of 200 nm to 500 nm are preferably used, and ultraviolet rays having a wavelength of 250 nm to 360 nm are more preferable.

  Ultraviolet rays can be irradiated using a double-sided mask aligner, a high-pressure mercury lamp, an ultra-high pressure mercury lamp, a high-intensity ultraviolet spot light source device, an ultraviolet laser, a metal halide lamp, or the like.

The irradiation intensity of ultraviolet light is preferably at 10 mW / cm ² or more 5000 mW / cm ² or less, more preferably 10 mW / cm ² or more 2500 MW / cm ² or less, 10 mW / cm ² or more 2000 mW / cm ² or less More preferably it is.

The irradiation time of the ultraviolet rays is preferably from 50 seconds to 10,000 seconds, more preferably from 50 seconds to 500 seconds, and further preferably from 80 seconds to 180 seconds.
Since the gel obtained by irradiation shows autonomy and changes spontaneously and periodically with the passage of time depending on the environment, it is desirable to set the irradiation time in the above range.

  The irradiation amount of ultraviolet rays preferably satisfies the following formula (2). When ultraviolet rays are irradiated with an irradiation amount satisfying the formula (2), the shape of the autonomously responsive gel is excellent.

100000 ≧ irradiation intensity (mW / cm ² ) × irradiation time (seconds) ≧ 500 Formula (2)

The irradiation amount represented by “irradiation intensity (mW / cm ² ) × irradiation time (seconds)” is more preferably 500 or more and 90000 or less, and further preferably 1200 or more and 65000 or less.

(Washing)
The gel obtained by irradiation is washed. As the cleaning liquid, it is preferable to use a solvent in which the unreacted monomer is dissolved so that the unreacted monomer is washed away. Examples of such a solvent include methanol, ethanol, dimethyl sulfoxide (DMSO) and the like.

<Manufacturing method of autonomous responder>
The reaction substrate 16 is filled in the gap between the array 10 of the autonomously responsive gel obtained by the above method. The reaction substrate 16 is contained in a polar solvent such as water, ethanol, or methanol, and filled in the gaps of the array 10 of the autonomously responsive gel.
Furthermore, an additive such as a gelling agent such as agar, a thickener, or a polymerization accelerator may be added to the solvent containing the reaction substrate 16.
The solvent containing the reaction substrate 16 may be filled so that the entire autonomously responsive gel array 10 is immersed, or may be filled so that a part is immersed.

<Autonomous response method and autonomous response device>
The autonomous responder of the present invention changes spontaneously and periodically over time.
For example, since the autonomously responsive gel having the Ru complex or the like periodically undergoes redox changes in the BZ reaction solution, it can autonomously and periodically swell and contract. Therefore, the autonomously responsive gel formed as an array controls the propagation of the chemical reaction wave by the BZ reaction solution, so that the swelling / contraction motion propagates over time between the protrusions 12 of the autonomously responsive gel, and the artificial flagella Can be expected.

  In addition, since the autonomously responsive gel having the Ru complex can periodically change its color tone in the BZ reaction solution, application to an automatonic energy filter or the like is also expected.

  Thus, the autonomous responder of the present invention is expected to be applied to small actuators suitable for transport of minute substances and cellular automaton type energy filters.

  In the autonomous responder of the present invention, an autonomous response phenomenon is induced by a partial external stimulus. For example, when a voltage is applied as an external stimulus, an autonomous response phenomenon is induced using a voltage signal as a trigger. In this case, the occurrence and stop of the response phenomenon can be controlled by applying a voltage.

  As a method for applying the voltage, a method using a metal probe connected to a voltage power source as shown in FIG. In the method of FIG. 3, one metal probe 40 is connected to the array 10 of autonomously responsive gel, the other metal probe 42 is brought into contact with the reaction substrate 16, and the voltage application device 44 is connected between the metal probes 40, 42. Apply voltage to

The autonomous responder of the present invention may be an autonomous response device incorporating an electrode and a voltage application device as described below.
The autonomous response device of the present invention applies the voltage to the array of the autonomous response gel, the reaction substrate filled in the gap of the array, an electrode connected to a part of the array, and the electrode. A voltage applying device.

FIG. 4 is a schematic diagram showing an example of the autonomous response device 50 of the present invention.
In the autonomous response device 50 shown in FIG. 4, an array 10 of autonomous response gels, electrodes 52, 53, 54, 55 connected to a part of the array 10, and a voltage application device (Fig. Not shown). A reaction substrate 16 (not shown) is filled in the gap between the autonomously responsive gel arrays 10. In the autonomously responsive gel array 10, a plurality of protrusions 12 are connected by an autonomously responsive gel layer 14.

  The electrodes 52, 53, 54, and 55 are preferably made of a noble metal such as gold or platinum so as not to be deteriorated by the reaction substrate 16.

Whether the metal probe is used as shown in FIG. 3 or the autonomous response device is used as shown in FIG. 4, the voltage applied to the autonomous responder is appropriately set according to the oxidation-reduction potential of the autonomous responsive gel. It is preferable.
For example, when making an autonomous response by BZ reaction in an autonomously responsive gel having a Ru complex, the voltage applied to the autonomous responder is preferably −2V to −0.5V, and −1.5V to −0.5V. More preferably, it is more preferably -1.5V to -1.0V.

  By the effect of the present invention, the autonomous response phenomenon due to the change of the oxidation state and the reduction state of the gel array can be controlled by the external potential. Even when the autonomous response phenomenon does not occur, when a voltage is applied to a part, a redox reaction of the catalyst contained in the gel is induced locally, and the valence of the catalyst metal is changed. Thereafter, the reaction substrate diffuses through the autonomously responsive gel layer connecting the gel protrusions, thereby inducing an oxidation-reduction reaction of the catalyst of the adjacent gel protrusion. This further interacts with the adjacent gel protrusions over time, and causes an autonomous response phenomenon in a chained manner.

  Hereinafter, the present invention will be described by way of examples. However, the autonomous responder of the present invention and an example of a manufacturing method thereof will be described, and the present invention is not limited to these examples.

  In addition, the dimension described in the Example is a value measured with a scanning electron microscope S-5500 manufactured by Hitachi High-Technologies Corporation.

[Example 1]
<Production of gel>
(Preparation of gel precursor solution)
・ N-isopropylacrylamide 168mg
・ Compound represented by the following chemical formula (3) (compound having Ru (bby) ₃ ) 10 mg
・ N, N'-methylenebisacrylamide (MBAAm) (crosslinking agent) 12mg
・ Irgacure 651 (polymerization initiator) 19mg
・ Ethanol 540μl
・ Dimethyl sulfoxide (DMSO) 60μl

  What was mixed by the said mixing | blending was deaerated and nitrogen-substituted, oxygen was removed, and the gel precursor solution was prepared.

(UV irradiation)
A polymer sheet (thickness 50 μm to 100 μm) was provided as a spacer on the glass plate, the gel precursor solution was poured into the gap, and a glass plate was further disposed thereon.
Here, ultraviolet rays having a wavelength of 405 nm and 15 W / cm ² were irradiated for 100 seconds by a double-sided mask aligner (PEM-800, manufactured by Union Optics Co., Ltd.).

(Washing)
The gel obtained by irradiation was thoroughly washed with ethanol to wash away unreacted monomers. The resulting gel array was stored in ethanol.

<Observation>
FIG. 5 shows an electron micrograph of a cross section of the obtained autonomously responsive gel array. As shown in the electron micrograph of FIG. 5, an autonomously responsive gel protrusion having a diameter of about 60 μm and an axial length (height) of about 50 μm is connected by an autonomously responsive gel layer having a thickness of 8 μm. A responsive gel array was obtained.

[Examples 2 to 6]
An array of autonomously responsive gels was prepared in the same manner as in Example 1 except that the ultraviolet irradiation time in Example 1 was changed to 80 seconds, 90 seconds, 95 seconds, 110 seconds, and 120 seconds.
The obtained array of autonomous responsive gel was observed with an electron micrograph in the same manner as in Example 1, and the length (height) in the axial direction and the thickness of the autonomous responsive gel layer were measured. The results are shown in Table 1.

  From the results of Examples 1 to 6, it was found that the thickness of the autonomous responsive gel layer can be adjusted by changing the irradiation time (total irradiation amount).

[Example 7]
<Observation of BZ vibration phenomenon>
(Preparation of gel)
The gel obtained in Example 1 was immersed in ethanol, sealed, stored at room temperature, and then dried at room temperature for 1 hour.

Nitric acid 7000 μL (1.4 M) and water 1952 μL were applied to the dried gel.
To this, 840 μL (0.084 M) of sodium bromate was added to oxidize the gel and waited for the gel to change from orange to green. After the gel turned green, 208 μL (0.0625) of malonic acid was added.

Therefore, the composition of the BZ reaction solution applied to the gel is as follows.
(BZ reaction solution composition)
・ Nitric acid 7000μL (1.4M)
・ Water 1952μL
-Sodium bromate 840μL (0.084M)
・ Malonic acid 208μL (0.0625M)

  In this state, when a direct current voltage of −0.8 V is applied to the gel using a metal probe as shown in FIG. 3 at 20 ° C., green (oxidized state) to orange (reduced) centering on the contacted portion of the metal probe. The region changed to orange (reduction region) moved so as to rotate counterclockwise around the contacted portion of the metal probe.

  The photograph showing the state is shown in FIGS. FIG. 6 (A) is a photograph showing the appearance of the gel array when 2 minutes have elapsed since the DC voltage of −0.8 V was applied. FIG. (A) is a photograph showing the state of the gel array when 5 minutes have elapsed since the application of the -0.8 V DC voltage.

FIGS. 7A and 7B are diagrams for explaining FIGS. 6A and 6B so that the orange-colored regions (reduction regions) shown in the photographs of FIGS. 6A and 6B can be easily identified. ). 7A and 7B correspond to FIGS. 6A and 6B, respectively. In FIGS. 7A and 7B, reference numeral 60 denotes an orange area (reduction area), and reference numeral 62 denotes a green area (oxidation area).
As shown in FIGS. 6 and 7, the reduction region of the gel moved autonomously by application of voltage, and the autonomous response phenomenon of the gel was confirmed. The gel array prepared in Example 1 did not develop an autonomous response phenomenon unless a voltage was applied at 35 ° C. or lower.

[Example 8]
The BZ vibration phenomenon was observed in the same manner as in Example 7, except that the gel prepared in Examples 3 and 4 was used instead of the gel prepared in Example 1, or the applied voltage was changed. The results are shown in Table 2. In Table 2, ◯ represents that an autonomous response phenomenon was exhibited, and x represents that no autonomous response phenomenon was observed.

  As shown in Table 2, all the gels produced in Examples 1, 3, and 4 responded autonomously by application of voltage, and the autonomous response was controlled by application of voltage. These gel arrays did not develop an autonomous response phenomenon unless a voltage was applied at 35 ° C. or lower.

DESCRIPTION OF SYMBOLS 10 Array 12 Autonomously responsive gel 14 Autonomously responsive gel layer 16 Reaction substrate 18 Catalyst 20 Autonomous responder 30 Glass substrate 32 Thermal fusion seal 34 Precursor solution 36 Photomask 40, 42 Metal probe 44 Voltage application device 50 Autonomous response Apparatus 52, 53, 54, 55 Electrode 60 Area changed to orange (reduction area)
62 Region showing green color (oxidation region)

Claims (12)

A plurality of protrusions having a diameter of 1 μm to 1000 μm and an axial height of 20 μm to 400 μm formed of an autonomously responsive gel;
An autonomous responsive gel layer composed of an autonomously responsive gel of the same quality as that of the protrusion, connected at a part in the axial direction of the protrusion,
An array of autonomously responsive gels.   The array of autonomous responsive gel according to claim 1, wherein the thickness of the autonomous responsive gel layer is 1% or more and 30% or less with respect to the axial length of the protrusion.   The array of autonomous responsive gels according to claim 1 or 2, wherein the autonomously responsive gel is stimuli responsive. The autonomously responsive gel is
N-isopropylacrylamide,
A monomer having a ruthenium complex, a cerium complex, a manganese complex, or an iron-phenanthroline complex, which is a catalyst for the Belousov-Zhabotinsky reaction,
The array of autonomously responsive gels according to any one of claims 1 to 3, which has a structural unit derived from. 5. The autonomously responsive gel array according to claim 4, wherein the monomer having a ruthenium complex is a compound represented by the following chemical formula (1).
The array of autonomously responsive gels according to any one of claims 1 to 5,
A reaction substrate for transmitting reaction diffusion, filled in a gap between the arrays;
An autonomous responder with   The autonomous responder according to claim 6, wherein the reaction substrate is a mixed solution containing an organic acid, an inorganic acid, and an oxidizing agent. The array of autonomously responsive gels according to any one of claims 1 to 5,
A reaction substrate for transmitting reaction diffusion, filled in a gap between the arrays;
An electrode connected to a part of the array;
An electrode in contact with the reaction substrate;
A voltage applying device for applying a voltage to the electrode;
An autonomous response device having an autonomous response body.   An autonomous response method for an autonomous responder, wherein a voltage of -0.5 V to -2.0 V is applied to the autonomous responder according to claim 6 or 7. In the solution containing the precursor of the self-responsive gel,
Irradiate ultraviolet rays through a photomask,
The manufacturing method of the array of the autonomous responsive gel of any one of Claims 1-5. The manufacturing method of the array of the autonomous response gel of Claim 10 which irradiates the ultraviolet-ray whose irradiation intensity | strength is 10 mW / cm < ² > -5000 mW / cm < ² > for 50 second or more and 10,000 second or less. The manufacturing method of the array of the autonomous response gel of Claim 10 or Claim 11 which irradiates the said ultraviolet-ray with the irradiation amount satisfy | filling following formula (1).
100000 ≧ irradiation intensity (mW / cm ² ) × irradiation time (seconds) ≧ 500 Formula (1)