JP2003089896A - Particle arraying method, and particle arraying device manufactured by the method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To array particles with high regularity even when the particles are relatively large in specific gravity and ultra-fine in size. SOLUTION: The particles 11 are charged negative in Fig. 1 (A). When the positive electric field and the negative electric field are applied to an upper electrode 5 and a lower electrode 3, respectively, in this condition, the negative- charged particles 11 are attached to the upper electrode 5, and slightly moved upwardly against the gravity (Fig. 1 (B)). Then, the polarity of the upper and lower electrodes is switched immediately, and the negative electric field and the positive electric field are applied to the upper electrode 5 and the lower electrode 3, respectively, the particles 11 are attracted by the positive electric field applied to the lower electrode 3 in addition to the gravity, and moved toward the lower electrode 3 (Fig. 1 (C)). By repeating the conditions in Figs. 1 (B) and 1 (C) by adequately controlling the electric field to be applied, the particles arrayed regularly in the final state as shown in Fig. 1 (D) can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for arranging fine particles and a fine particle arranging apparatus manufactured by the method,
The fine particle array device can be applied to, for example, a high density recording medium, an optical element, a display device and the like.

[0002]

2. Description of the Related Art As a technique relating to arranging fine particles on a substrate, for example, the following are disclosed. Patent No. 2828374 (Method for forming two-dimensional aggregation of fine particles): A liquid dispersion medium of fine particles is spread on the surface of a substrate to form a liquid thin film, and the liquid thickness is made equal to or smaller than the particle diameter size, and the liquid is evaporated. The fine particles are two-dimensionally aggregated by the surface tension that acts in the lateral direction, and the fine particles are arranged.

Japanese Unexamined Patent Publication No. 9-230391 (Redispersion method of electric field array particles): A method of redispersing fine particles in an array state by applying voltage to opposing electrodes and utilizing electrophoretic phenomenon of fine particles. is there.

Japanese Unexamined Patent Publication No. 10-229090 (particle array device): A moving electric field is formed by applying a voltage in a predetermined order to each of the electrodes formed in parallel, and fine particles are generated by the force of the moving electric field. Are moved, and the fine particles are dropped into the openings formed at predetermined positions during the movement to be arranged at predetermined positions.

Reference: "A new method for forming a three-dimensional organic photonic crystal" (O plus E Vol. 21, No. 12 200)
(0PP1549-1553) Polystyrene fine particles that are three-dimensionally integrated are obtained by controlling the evaporation rate of a solution in which polystyrene fine particles are dispersed and making sedimentation due to gravity very slow.

[0006]

The present invention relates to a method for arranging fine particles and an apparatus for arranging fine particles produced by the method, and particularly to fine particles having a high specific gravity or ultrafine particles which do not spontaneously settle by gravity alone. Even more specifically, the present invention provides a fine particle arranging method capable of arranging fine particles at a high density and regularly in a two-dimensional or three-dimensional structure by using a simple process, and a fine particle arranging apparatus manufactured by the fine particle arranging method.

In recent years, it has been found that by making a material into fine particles, various characteristics which were not obtained in the bulk shape can be obtained. In addition, research results by a method of accurately forming the shape and particle diameter of the fine particles. Has been announced and its application is being actively researched. Naturally, proposals have been made to use the fine particle material in the form of fine particles as it is, but in order to further utilize the characteristics of the fine particles, finely arranged fine particles are regularly arranged, and applied research utilizing the resulting performance is also active.

For example, in Japanese Patent No. 2828374, a liquid dispersion medium of fine particles is spread on the surface of a substrate to form a liquid thin film, and the liquid thickness is made equal to or smaller than the particle size.
An invention is disclosed in which fine particles are two-dimensionally aggregated and arrayed by the surface tension acting in the lateral direction when the liquid evaporates.
However, according to the present invention, the arrangement of the obtained fine particles is 2
However, it is impossible to obtain a three-dimensional structure required for a photonic crystal, which is expected in the optical communication field in the future.

Further, as a technique utilizing the electrophoretic phenomenon of fine particles, there is Japanese Patent Application Laid-Open No. 9-230391, the contents of which are arranged by applying a voltage to opposing electrodes and utilizing the electrophoretic phenomenon of fine particles. The fine particles in 1 are redispersed to control the transmission and blocking of light. It can be said that this conventional technique is similar to the present invention in that it utilizes the electrophoretic phenomenon of fine particles, but the control method of this conventional technique controls the array state and redispersion state to transmit light, This is for controlling the interruption, and is fundamentally different from that for obtaining a highly ordered three-dimensional fine particle array device as in the present invention.

Different from the above-mentioned two prior arts, as a technique for obtaining a three-dimensional structure, the above-mentioned document (O plus E
Vol.21, No.12 2000 PP1549-
1553), and this document discloses that three-dimensionally integrated polystyrene fine particles are obtained by controlling the evaporation rate of a solution in which polystyrene fine particles are dispersed and making the sedimentation due to gravity very slow. . However, in addition to the problem that this technology can be applied only to polystyrene particles having a relatively low specific gravity,
Since it uses a passive control technology that "slows sedimentation by gravity very slowly," it is an ineffective technology for particles that do not sediment by gravity, such as ultrafine particles.

The technique closest to the present invention is disclosed in Japanese Patent Laid-Open No.
As disclosed in Japanese Patent Application Laid-Open No. 0-229090, a moving electric field is formed by applying a voltage to each of the electrodes formed in parallel in a predetermined order, and fine particles are moved by the force of the moving electric field. There is a technique in which the fine particles are arranged in a predetermined position by dropping them into an opening formed in a predetermined position during movement. However, this technique is remarkable as a technique for arranging fine particles having a relatively large specific gravity, but in addition to using a very complicated process in which the upper and lower electrodes need to be formed separately, Due to the arraying technique in the dry state, there is a limit to the size of the fine particles that can be applied. That is, in general, due to the characteristics of the fine particles, the smaller the particle size, the greater the cohesive force becomes, and this phenomenon is a major obstacle in the arrangement, so it will be needed more and more in the future. The ultrafine particles have a big problem that they cannot be applied due to the obstacle of the cohesive force of themselves.

The present invention has been made in order to solve the above-mentioned problems, and in a solution system in which fine particles are dispersed, by applying an electric field efficiently, a relatively large specific gravity and ultrafine particles are obtained. The purpose is to provide a technology for arranging fine particles with high regularity, and completed by the fusion of technologies for removing only the solution component downward during or after the array. It is an object of the present invention to provide a technique for accurately arranging fine particles regularly by a simple process.

[0013]

According to a first aspect of the present invention, there is provided a method for manufacturing a fine particle arranging device in which fine particles are arranged,
At least a container capable of holding a solution, a lower electrode on the lower part of the container, and an upper electrode on the upper part of the container are used to hold a solution in which fine particles are dispersed in the container. It is characterized in that fine particles are regularly arranged in the container by utilizing an electrophoretic phenomenon caused by applying a voltage to the electrode or one of the electrodes.

According to a second aspect of the invention, in the first aspect of the invention, when a direct current voltage is applied to the upper and lower electrodes, a so-called alternating electric field that alternately changes polarities is applied. It is a thing.

According to a third aspect of the invention, in the first aspect of the invention, an alternating voltage is applied to either the upper or lower electrode, and a direct voltage is applied to the other electrode in synchronization with the frequency. It is characterized by.

The invention of claim 4 is characterized in that, in any one of the inventions of claims 1 to 3, it includes a step of gradually decreasing the voltage applied to the lower and upper electrodes or one of the electrodes. It is a thing.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, a lower base material having the lower electrode on an upper portion is provided, and the lower base material is a porous material. It was done.

According to a sixth aspect of the present invention, in the fifth aspect, the porous material is zeolite.

According to a seventh aspect of the present invention, in the fifth aspect, the porous material is porous silicon.

The invention of claim 8 is the invention according to any one of claims 5 to 7, wherein during or after the fine particle arrangement,
Only the solution component is removed downward through the pores of the base material.

According to a ninth aspect of the invention, in the eighth aspect of the invention, the arrayed fine particles left on the substrate are fixed with an ultraviolet curable resin.

The invention of claim 10 is characterized in that, in the invention of claims 5 to 9, the liquid property of the liquid in which the fine particles are dispersed is optimized in accordance with the base material and the fine particles. .

The invention of claim 11 is a fine particle array device manufactured by the method according to any one of claims 1 to 10.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a sectional view schematically showing a method for manufacturing a fine particle array device according to the present invention. In the figure, 1 is a container, 2 is a lower base material of the container 1, and 3 is a container. The lower electrode provided on the lower substrate 2, 4 is the upper substrate of the container 1, 5 is the upper electrode provided under the upper substrate 4, and 6 and 7 are DC voltage control devices. (A) shows a state in which the solution 10 in which the fine particles 11 are dispersed is present in the container 1 and no electric field is applied to the upper electrode 5 and the lower electrode 3.

At this time, the fine particles 11 are assumed to be negatively charged. FIG. 1B schematically shows the behavior of the fine particles when a positive electric field is applied to the upper electrode 5 and a negative electric field is applied to the lower electrode 3 in this state. The negatively charged fine particles 11 are attracted to the positive electric field applied to the upper electrode 5, and move slightly upward against the gravity. Figure 1 (B)
Immediately after this, switch the polarity of the upper and lower electrodes,
The behavior of the fine particles 11 when a negative electric field is applied to the upper electrode 5 and a positive electric field is applied to the lower electrode 3 is schematically shown. In this state, the fine particles 11 are attracted to the positive electric field applied to the lower electrode 3 in addition to gravity, and are thus attracted to the lower electrode 3.
Move to. Then, by appropriately controlling the applied electric field, this state, that is, FIG.
By repeating the state of (C), it is possible to finally obtain finely arranged fine particles as shown in FIG.

FIG. 2 is a diagram schematically showing a state in which a porous material is used as the lower base material 2. In the state shown in FIG. 1 (D) or after application of an electric field, When a porous material is used for the lower base material 2 having the lower electrode 3 as shown in FIG. 2, the solution 10 is removed downward as droplets 10 'through the pores, so that the fine particles in a dry state can be obtained. The array device can be easily obtained.

Further, in the dried state, for example, as shown in FIG. 3, the ultraviolet curable resin 20 is dropped and the resin is cured by irradiating with ultraviolet light to form a regular three-dimensional pattern as shown in FIG. It is possible to easily obtain an arraying device of the fine particles 11 accumulated in the above, and it is possible to apply to a photonic crystal or the like. It is not always necessary to drip the ultraviolet curable resin 20 after it has been dried, and in the state where there is a solution,
It is also possible to drop the ultraviolet curable resin and irradiate it with ultraviolet light to cure the resin.

The present invention provides a highly ordered fine particle array device,
One of the features is that it is realized by using a solution system, that is, even in the dry state, even ultrafine particles that tend to aggregate easily utilize the advantages of the solution system to the maximum extent to improve dispersibility. To prevent aggregation,
pH control, eg, proper selection of ionic species to be added,
By controlling, the relationship of the isoelectric point with the lower electrode can be utilized, and as a result, a highly ordered fine particle array can be obtained.

This point will be described in more detail. Generally, for example, when fine particles made of a metal oxide are immersed in water, the fine particles have a positive or negative electric charge, and when an electric field is present, the fine particles move in a direction having opposite electric fields. This phenomenon is an electrophoretic phenomenon. By this electrophoretic phenomenon, it is possible to know the charge of the particles in water, that is, the existence of the interfacial potential (zeta potential). This interfacial potential changes greatly depending on the pH of the fine particle-water system. Generally, when the horizontal axis is the pH of an aqueous system and the vertical axis is the interfacial potential, the interfacial potential changes depending on the pH of the aqueous system, and the pH of the aqueous system at the point where the interfacial potential is "0" is defined as the "isoelectric point". It From this phenomenon, generally, the interfacial potential on the surface of the metal oxide fine particles has a positive polarity on the acidic side and a negative polarity on the alkaline side.

However, this isoelectric point varies greatly depending on the material. For example, colloidal silica has a value of "2.0", α.
-The value "9.0" is introduced for alumina and "6.7" for hematite. In other words, the interfacial potential increases with increasing distance from the isoelectric point, the interfacial potential increases toward the positive side with increasing acidity, and conversely, the interfacial potential increases with increasing negative polarity toward the alkaline side. Go to This is p
It can be controlled by H. pH control is
It can be controlled with good controllability by adding acid or alkali.

The present invention positively utilizes this phenomenon,
A major feature is that the particles can be regularly arranged in three dimensions by the electrophoretic phenomenon while preventing the particles from aggregating. As mentioned above, the concept of isoelectric point,
Also, it is fundamentally different from the dry process in which the electrophoretic phenomenon cannot be used.

Still another feature is that the electric field applied to the upper and lower electrodes can be a direct current, an alternating current, or a combination of both depending on the particles used and the pH of the solution. Further, it is not always necessary to apply an electric field having a constant intensity, and for example, it is possible to control the electric field to be most stable in a short time by gradually weakening the intensity of the applied electric field. It is a point. As a result, it is possible to finally obtain the most stable state, that is, a fine particle structure having no defects and arranged with high regularity.

Due to these characteristics, unlike the conventional arraying technique, the material of the applicable fine particles and the range of the particle size are expanded, and naturally, even the fine particles which cannot be regularly aggregated in a dry state can be arranged. It has a great feature that it can be applied, and as a result, the field of application is expanded accordingly, and can be applied to fine particles composed of a wide range of materials.

Example 1 (1) Formation of Base Material and Container Having Lower Electrode About 2 μm of gold was deposited by sputtering on a quartz substrate having a size of 50 mm × 50 mm and a thickness of 0.5 mm, and the center of the substrate surface was formed. Inner diameter 20 mm x 20 mm, outer diameter 22 mm x 22 m
A rectangular parallelepiped quartz tube of m and a height of 15 mm was adhered by a known means to form a base material having a lower electrode and a container. Further, a voltage control device capable of pulse driving was connected to the lower electrode so that a positive electric field could be applied. (2) Preparation of fine particle dispersion liquid Colloidal silica (MP manufactured by Nissan Kagaku Co., Ltd.) was added to 90 mL of pure water.
-4540 average particle size = 450 nm 40%) 1 solution
0 mL was added and thoroughly stirred to prepare a 4% colloidal silica dispersion liquid.

(3) Formation of Base Material Having Upper Electrode A base material having a gold thin film functioning as an upper electrode was formed in the same manner as the formation of the base material having a lower electrode. Also,
Connect a voltage control device capable of pulse drive to the upper electrode,
A negative electric field can be applied. (4) Filling of dispersion liquid and installation of base material having upper electrode The fine particle dispersion liquid prepared in (2) was filled in a container until a slight overflow occurred. Immediately, the substrate having the upper electrode was covered and fixed with a clamp. In this state, the container was almost sealed.

(5) Alternating electric fields with different polarities were applied to the upper and lower electrodes of the fine particle array by applying an electric field. The voltage was 50 V and the driving frequency was 10 Hz. FIG. 5 shows a time chart of the electric fields applied to the upper and lower electrodes at this time. 2 in this state
It was maintained for 0 minutes, and finally, it was maintained for 10 minutes while applying -50 V to the lower electrode. During this time, the clamp was removed, and the base material having the upper electrode was gently displaced and removed.
In this state, the container was opened.

(6) Drying of solution components When the container was opened, the solution components were allowed to dry naturally, taking care not to give vibration.
Drying was complete after about 2 hours. (7) Evaluation of Fine Particle Arrangement Device The obtained three-dimensional fine particle arrangement device was observed using a scanning electron microscope (SEM). As a result, it was found that the structure had a close-packed structure although there were some defects. confirmed.

Example 2 (1) Formation of Base Material and Container Having Lower Electrode Gold film of about 2 μm was formed on a quartz substrate having a size of 50 mm × 50 mm and a thickness of 0.5 mm by the sputtering method, and the center of the substrate surface was formed. Inner diameter 20 mm x 20 mm, outer diameter 22 mm x 22 m
A rectangular parallelepiped quartz tube of m and a height of 15 mm was adhered by a known means to form a base material having a lower electrode and a container. Further, a voltage control device capable of alternating voltage was connected to the lower electrode so that an electric field by alternating current could be applied. (2) Preparation of fine particle dispersion A fine particle dispersion was prepared under the same conditions as in Example 1.

(3) Formation of Base Material Having Upper Electrode A base material having a gold thin film functioning as an upper electrode was formed in the same manner as the formation of the base material having a lower electrode. Also,
Connect a voltage control device capable of pulse drive to the upper electrode,
A negative electric field can be applied. (4) Filling of dispersion liquid and installation of base material having upper electrode The fine particle dispersion liquid prepared in (2) was filled in a container until a slight overflow occurred. Immediately, the substrate having the upper electrode was covered and fixed with a clamp. In this state, the container was almost sealed.

(5) A 15 Hz alternating current electric field was applied to the lower electrode of the fine particle array by applying an electric field. The voltage was 50V. A DC electric field was applied to the upper electrode, but the timing was controlled as follows. A positive electric field of -20 V was applied to the upper electrode only when a negative electric field was applied to the lower electrode. FIG. 6 shows a time chart of the electric fields applied to the upper and lower electrodes at this time. This state was maintained for 10 minutes, then the applied voltage was reduced by 0.2 V / sec for both the upper electrode and the lower electrode, and after 100 seconds, an alternating current of 30 V was applied to the lower electrode. This state was maintained for 10 seconds, and the voltage applied to the lower electrode was decreased by 0.2 V per second. This state was maintained for 5 minutes. During this time, the clamp was removed, and the base material having the upper electrode was gently displaced and removed. In this state, the container was opened.

(6) Drying of solution component When the container was opened, the solution component was allowed to dry naturally, taking care not to give vibration. (7) Evaluation of Fine Particle Arrangement Device The obtained three-dimensional fine particle arrangement device was observed using a scanning electron microscope (SEM). As a result, it was found that the structure had a close-packed structure although there were some defects. confirmed.

Example 3 (1) Formation of Substrate with Lower Electrode and Container Different from the previous examples, a zeolite sintered body of 50 mm × 50 mm and a thickness of 2.5 mm was used as the substrate with the lower electrode. Was used. A gold film of about 2 μm was formed on this substrate by a sputtering method, and the inner diameter of the substrate surface was 20 mm × 2.
A rectangular parallelepiped quartz tube having an outer diameter of 0 mm, an outer diameter of 22 mm × 22 mm, and a height of 15 mm was adhered by a known means to form a base material having a lower electrode and a container. Further, a voltage control device capable of pulse driving was connected to the lower electrode so that a positive electric field could be applied. (2) Preparation of fine particle dispersion A fine particle dispersion was prepared under the same conditions as in Example 1.

(3) Formation of Base Material Having Upper Electrode On a quartz substrate having a size of 50 mm × 50 mm and a thickness of 0.5 mm, about 2 μm of gold was deposited by a sputtering method to obtain a base material having a lower electrode. Also, a voltage control device capable of pulse driving was connected to the lower electrode so that a negative electric field could be applied. (4) Filling of dispersion liquid and installation of base material having upper electrode The fine particle dispersion liquid prepared in (2) was filled in a container until a slight overflow occurred. Immediately, the substrate having the upper electrode was covered and fixed with a clamp. In this state, the container was almost sealed.

(5) Alternating electric fields with different polarities were applied to the upper and lower electrodes of the fine particle array by applying an electric field. The voltage was 50 V and the driving frequency was 10 Hz. This state was maintained for 20 minutes, and finally, a state in which -50 V was applied to the lower electrode was maintained for 10 minutes. During this time, the clamp was removed, and the base material having the upper electrode was gently displaced and removed. In this state, the container was opened.

(6) When the drying container for the solution component was opened, only the solution component was discharged downward through the pores of the zeolite, taking care not to give vibration. It took about 30 minutes for all the solution components to drain. (7) Evaluation of Fine Particle Arrangement Device When the obtained three-dimensional fine particle arrangement device was observed using a scanning electron microscope (SEM), it was confirmed that it had a close-packed structure with almost no defects. It was

(Example 4) (1) Formation of base material and container having lower electrode Gold was deposited to a thickness of about 2 μm on a quartz substrate having a size of 50 mm × 50 mm and a thickness of 0.5 mm by the sputtering method, and the center of the substrate surface was formed. Inner diameter 20 mm x 20 mm, outer diameter 22 mm x 22 m
A rectangular parallelepiped quartz tube of m and a height of 15 mm was adhered by a known means to form a base material having a lower electrode and a container. Further, a voltage control device capable of pulse driving was connected to the lower electrode so that a positive electric field could be applied.

(2) Preparation of fine particle dispersion A fine particle dispersion was prepared under the same conditions as in Example 1. (3) Formation of Base Material Having Upper Electrode A base material having a gold thin film functioning as an upper electrode was formed in the same manner as the formation of the base material having a lower electrode. Also,
Connect a voltage control device capable of pulse drive to the upper electrode,
A negative electric field can be applied.

(4) Filling of Dispersion Liquid and Installation of Substrate Having Upper Electrode The fine particle dispersion liquid prepared in (2) was filled in a container until a slight overflow occurred. Immediately, the substrate having the upper electrode was covered and fixed with a clamp. In this state, the container was almost sealed. (5) An alternating electric field was applied to the upper and lower electrodes of the fine particle array by applying an electric field with respective polarities. The voltage was 50 V and the driving frequency was 10 Hz. FIG. 6 shows a time chart of the electric fields applied to the upper and lower electrodes at this time. 2 in this state
It was maintained for 0 minutes, and finally, it was maintained for 10 minutes while applying -50 V to the lower electrode. During this time, the clamp was removed, and the base material having the upper electrode was gently displaced and removed.
In this state, the container was opened.

(6) When the fixing container of the apparatus for arranging the fine particles of the ultraviolet curable resin is in an open state, be careful not to give vibration to the ultraviolet curable resin (manufactured by Three Bond Co.).
5 mL of one-component UV curable resin was gently added dropwise. Ultraviolet irradiation was performed for 1 minute using an ultraviolet irradiation device (wavelength: 312 nm). As a result, the immobilized fine particle array device was obtained. (7) Evaluation of fine particle array device The obtained three-dimensional fine particle array device was observed using a scanning electron microscope (SEM). It has been confirmed that

(Example 5) (1) Formation of base material having lower electrode and container As in the case of Example 3, a base material having a lower electrode of 50 m was formed.
A zeolite sintered body having a size of m × 50 mm and a thickness of 2.5 mm was used. A gold film having a thickness of about 2 μm was formed on this substrate by a sputtering method, and a rectangular parallelepiped quartz tube having an inner diameter of 20 mm × 20 mm, an outer diameter of 22 mm × 22 mm, and a height of 15 mm was adhered to the center of the substrate surface by a known means to form a lower electrode. A base material and a container were formed. Further, a voltage control device capable of pulse driving was connected to the lower electrode so that a positive electric field could be applied.

(2) Preparation of Fine Particle Dispersion A fine particle dispersion was prepared under the same conditions as in Example 1. (3) Formation of Base Material Having Upper Electrode A quartz substrate having a size of 50 mm × 50 mm and a thickness of 0.5 mm was deposited with a thickness of about 2 μm of gold by a sputtering method to obtain a base material having a lower electrode. Also, a voltage control device capable of pulse driving was connected to the lower electrode so that a negative electric field could be applied.

(4) Filling of Dispersion Liquid and Installation of Substrate Having Upper Electrode The fine particle dispersion liquid prepared in (2) was filled in a container until it overflowed slightly. Immediately, the substrate having the upper electrode was covered and fixed with a clamp. In this state, the container was almost sealed. (5) An alternating electric field was applied to the upper and lower electrodes of the fine particle array by applying an electric field with respective polarities. The voltage was 50 V and the driving frequency was 10 Hz. This state was maintained for 20 minutes, and finally, a state in which -50 V was applied to the lower electrode was maintained for 10 minutes. During this time, the clamp was removed, and the base material having the upper electrode was gently displaced and removed. In this state, the container was opened.

(6) When the fixing container of the fine particle arraying apparatus using the ultraviolet curable resin is in the open state, as shown schematically in FIG. 3, taking care not to give vibration, the ultraviolet curable resin (three bond) is used. One-component UV curable resin manufactured by the company)
5 mL was dropped gently and the ultraviolet irradiation device (wavelength: 312
(nm) was used for ultraviolet irradiation for 3 minutes. As a result, the immobilized fine particle array device was obtained. (7) Evaluation of fine particle array device The obtained three-dimensional fine particle array device was observed using a scanning electron microscope (SEM). It has been confirmed that

Example 6 (1) Formation of Base Material and Container Having Lower Electrode About 2 μm of gold was deposited by sputtering on a quartz substrate having a size of 50 mm × 50 mm and a thickness of 0.5 mm, and the center of the substrate surface was formed. Inner diameter 20 mm x 20 mm, outer diameter 22 mm x 22 m
A rectangular parallelepiped quartz tube of m and a height of 15 mm was adhered by a known means to form a base material having a lower electrode and a container. Further, a voltage control device capable of pulse driving is connected to the lower electrode so that a negative electric field can be applied unlike the previous embodiments. The reason for this will be described below.

(2) Preparation of Fine Particle Dispersion In this example, different from the previous examples, pure water 90
Alumina fine particles (AO-5 manufactured by Admatex Co., Ltd.)
02 average particle size = about 700 nm) was dispersed in 5 mg liquid, and 200 μL of hydrochloric acid (JIS special grade 35.0-37.0% manufactured by Kanto Chemical Co., Inc.) was added to control the liquidity to be acidic.
Was added. The pH of the dispersion was "2.55". The reason for doing this is as follows. That is, since the isoelectric point of alumina fine particles is generally said to be “9.0”, the interface potential is not so large in a neutral (pH = 7.0) solution like pure water. Therefore, in order to allow the alumina fine particles to be electrophoresed with good controllability, it is effective to make the liquidity acidic and increase the interfacial potential. By using a solution system as in the present invention, it is possible to control the liquidity and to apply it to a wide range of materials.

(3) Formation of Base Material Having Upper Electrode A base material having a gold thin film functioning as an upper electrode was formed in the same manner as the formation of the base material having the lower electrode. Also,
Connect a voltage control device capable of pulse drive to the upper electrode,
A positive electric field can be applied. (4) Filling of dispersion liquid and installation of base material having upper electrode The fine particle dispersion liquid prepared in (2) was filled in a container until a slight overflow occurred. Immediately, the substrate having the upper electrode was covered and fixed with a clamp. In this state, the container was almost sealed.

(5) Alternating electric fields with different polarities were applied to the upper and lower electrodes of the fine particle array by applying an electric field. The voltage was 50 V and the driving frequency was 10 Hz. FIG. 6 shows a time chart of the electric fields applied to the upper and lower electrodes at this time. 2 in this state
It was maintained for 0 minutes, and finally, it was maintained for 10 minutes while applying -50 V to the lower electrode. During this time, the clamp was removed, and the base material having the upper electrode was gently displaced and removed.
In this state, the container was opened.

(6) Drying of solution components When the container was opened, the solution components were allowed to dry naturally, taking care not to apply vibration.
Drying was complete after about 2 hours. (7) Evaluation of Fine Particle Arrangement Device The obtained three-dimensional fine particle arrangement device was observed using a scanning electron microscope (SEM). As a result, it was found that the structure had a close-packed structure although there were some defects. confirmed.

[0059]

The action and effect solution system according to claim 1, that is, a solution in which fine particles are dispersed is held in a container, and only the gravity is used to arrange the fine particles by applying a voltage to the lower and upper electrodes. Thus, it is possible to prepare a fine particle arranging device having high regularity even for ultrafine particles that do not settle.

Action and Effect Corresponding to Claim 2 In order to apply a so-called alternating electric field, which changes the polarity alternately when a DC voltage is applied to the upper and lower electrodes, sedimentation due to gravity and movement due to the electric field are performed. It can be controlled optimally.

Action and Effect Corresponding to Claim 3 In order to apply an AC voltage to one of the upper and lower electrodes and to apply a DC voltage to the other electrode in synchronization with the frequency, a simple process is performed. The fine particles can be arranged with good controllability.

Since the method includes the step of gradually decreasing the voltage applied to the working effect electrode corresponding to claim 4, it is an efficient and short-time most stable state, that is, there is no defect and high. It is possible to obtain a fine particle structure that is regularly arranged.

Since the lower base material having the lower electrode having the function and effect corresponding to claim 5 is a porous material,
Only the solution component can be removed downward during or after the fine particle arrangement, and a dry three-dimensional fine particle arrangement device can be easily obtained.

Since the porous material is zeolite, it is safe and easy to handle, and the solution component has a high passage speed.

Action and Effect Corresponding to Claim 7 Since the porous material is porous silicon, it is safe and easy to handle, and the solution component has a high passage speed.

Since the lower base material having the lower electrode having the function and effect corresponding to claim 8 is a porous material,
Only the solution component can be removed downward during or after the fine particle arrangement, and a dry three-dimensional fine particle arrangement device can be easily obtained. Further, it is possible to easily obtain a device having fine array particles having no defects and having high regularity.

Since the fine particles having the function and effect arrangement corresponding to the ninth aspect are fixed by using the ultraviolet curing resin, optical parts such as a photonic crystal and other applications can be easily made.

In order to optimize the liquidity of the liquid in which the fine particles are dispersed according to the substrate and the fine particles, fine aligned fine particles having no defects and having high regularity are used. The device it has is easily obtained.

[Brief description of drawings]

FIG. 1 is a cross-sectional view schematically showing a method for manufacturing a fine particle array device according to the present invention.

FIG. 2 is a diagram schematically showing a state in which a porous material is used as a lower base material.

FIG. 3 is a diagram schematically showing an example in which an ultraviolet curable resin is dropped and irradiated with ultraviolet light to cure the resin.

FIG. 4 is a diagram showing an example of a fine particle array device manufactured by the method of the present invention.

FIG. 5 is a diagram showing an example of a time chart of electric fields applied to upper and lower electrodes.

FIG. 6 is a diagram showing another example of a time chart of electric fields applied to upper and lower electrodes.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Container, 2 ... Lower base material, 3 ... Lower electrode, 4 ... Upper base material, 5 ... Upper electrode, 6,7 ... DC voltage control apparatus, 10 ...
Solution, 10 '... Droplet, 11 ... Fine particle, 20 ... UV curable resin.

Claims (11)

[Claims] 1. A method of manufacturing a fine particle arranging device in which fine particles are arranged, wherein at least a container capable of holding a solution, a lower electrode below the container, and an upper electrode above the container are used, A solution in which fine particles are dispersed is held in the container, and fine particles are regularly formed in the container by utilizing an electrophoretic phenomenon generated by applying a voltage to the lower electrode and the upper electrode or one of the electrodes. A method for arranging fine particles, which comprises arranging them. 2. The method of arranging fine particles according to claim 1, wherein when a direct current voltage is applied to the upper and lower electrodes, a so-called alternating electric field that alternately changes polarities is applied. 3. The fine particle array according to claim 1, wherein an AC voltage is applied to one of the upper electrode and the lower electrode, and a DC voltage is applied to the other electrode in synchronization with the frequency. Method. 4. The method of arranging fine particles according to claim 1, further comprising a step of gradually decreasing a voltage applied to the lower and upper electrodes or one of the electrodes. 5. The method for arranging fine particles according to claim 1, further comprising a lower base material having the lower electrode on an upper portion thereof, wherein the lower base material is a porous material. 6. The method of arranging fine particles according to claim 5, wherein the porous material is zeolite. 7. The method of arranging fine particles according to claim 5, wherein the porous material is porous silicon. 8. The method of arranging fine particles according to claim 5, wherein only the solution component is removed downward through the pores of the base material during or after the arrangement of the fine particles. 9. The arrayed fine particles left on the base material are fixed by using an ultraviolet curable resin.
5. The method for arranging fine particles according to item 4. 10. The method for arranging fine particles according to claim 5, wherein the liquid property of the liquid in which the fine particles are dispersed is optimized according to the base material and the fine particles. 11. A fine particle array device manufactured by the method according to claim 1.