JPH07112081B2 - Functional film with self-oscillation - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a functional film having a self-oscillation function.

(Prior Art) Until now, the development of transistors, ICs, LSIs, and VLSIs based on semiconductor technology centered on silicon has been carried out, and the foundation of today's electronics has been laid. On the other hand, with the elucidation of life or biological phenomena, expectations for the development of new materials and devices based on the idea peculiar to biological phenomena are increasing. This is based on the idea of imitating biological phenomena and playing a role in electronics technology based on principles different from those in the past in terms of information processing, recognition, and memory.

For example, the most basic of many phenomena peculiar to biological systems is not a phenomenon based on thermodynamic equilibrium as conventionally thought, but occurs in a non-equilibrium state far away from equilibrium. It is becoming clear from various facts that this is a phenomenon. If such a phenomenon can be applied to electronics, there is a possibility that the field of electronics based on a new way of thinking will be developed.

A typical example of the phenomenon that occurs from such a non-equilibrium non-equilibrium system is an oscillation phenomenon observed in a biological membrane or an artificial membrane (functional membrane) that mimics the biological membrane. An apparatus for observing the oscillation phenomenon in such a functional film is shown in FIG. In FIG. 1, a container 1 is divided into two chambers at its center by a partition wall 2 and a porous membrane (functional membrane) 3 containing lipid molecules attached to this partition wall 2. The container 1 has, for example, K of 0.1 molar concentration in one of the two compartments.
A Cl solution 4a and a 0.01 molar KCl solution 4b are contained in the other chamber. Each of the KCl solutions 4a and 4b has a current application electrode 5
The a and 5b are dipped, and a current flows by the power source 6 connected between both electrodes. Further, the membrane potential measuring electrodes 7a and 7b are immersed in the KCl solutions 4a and 4b, respectively, and the membrane potential is measured by an electrometer 8 connected between both electrodes.

When a constant current of, for example, about 10 ^-7 A / cm ^{2 is} passed between the current application electrodes 5a and 5b in the device having the configuration shown in FIG. 1, the electrometer 8 produces a periodic oscillation pattern as shown in FIG. Can be observed. Such a phenomenon can be regarded as a populationization of the excitement phenomenon of the biological membrane.

In the above-mentioned functional film, the oscillation cycle, waveform, and amplitude change in response to changes in salt concentration, current value, and other external pressures. Therefore, for example, current value as information (signal) Attempts have been made to read information from changes in the oscillation pattern of the film.

However, the change in the oscillation pattern of the functional film by these methods is generally not good in reproducibility for stimulation, that is, information (signal). In addition, there is a problem that it cannot respond when externally input parallel multiplex information.

(Problems to be Solved by the Invention) The present invention has been made to solve the above problems, and an object thereof is to provide a functional film capable of converting a plurality of information input from the outside.

[Means for Solving the Problems] (Means for Solving the Problems) The functional film having a self-oscillation function of the present invention is a bilayer film having lipid molecules as a main component, a lipid molecule film or lipid accumulated on a porous film. In a functional film consisting of a polymer film in which molecules are dispersed, two aqueous solutions are divided into two chambers, and a self-excited oscillation effect is produced by the difference in ion concentration between these aqueous solutions, change in external pressure, and application of external DC voltage. It is characterized in that the membrane containing the lipid molecule contains two or more kinds of substances selectively causing different chemical reactions by light of different wavelengths.

Examples of the lipid molecule include dioleoyl phosphate, triolein, monoolein, and other phospholipid molecules.

Examples of the porous film include cellulose-based porous filters such as acetyl cellulose, fluororesin-based, and vinyl chloride resin-based porous filters.

Examples of the polymer film include general-purpose polymer films such as polystyrene, polyethylene and polypropylene.

In the present invention, substances having various reaction forms can be used as the substance that causes a chemical reaction by light. Among these reaction forms, especially, the form of frequency, waveform, and amplitude of self-excited oscillation is changed when light is irradiated from the outside, and when the light from the outside is cut off, the self-excited oscillation is returned to the original state. Reaction, When the light is irradiated from the outside, the form of frequency, waveform, and amplitude of self-oscillation is changed, and the same form is maintained even if the light from the outside is cut off, but the light of different wavelength is irradiated. Therefore, a reaction that returns the self-excited oscillation to the original state is desirable.

Examples of substances that cause such a chemical reaction include functional groups that perform proton transfer such as keto-type and enol-type tautomerism, and heterocyclic cleavage such as photochromism from spiropyran-based molecules to merocyanine-based molecules. Functional groups that carry out reactions, functional groups that carry out cis-trans isomerization such as azobenzenes, stilbenes, etc., functional groups accompanied by strain deformation such as reactions between norvonadiene and quadxylene, or electron donors and electron acceptors. And a substance having a functional group that performs an electron transfer reaction between two types of molecules with and.

In the present invention, among these substances, two or more substances that selectively cause different chemical reactions by light of different wavelengths are used in combination. However, regarding the combination of these two or more kinds of substances, it is desirable that the light absorption energy region of each substance is larger than the wavelength width of incident light, and that each reaction does not interact with each other in the film.

These two or more substances are contained in a membrane containing lipid molecules. There are no particular restrictions on the method of incorporating these substances into the membrane, but a method of mixing them with the lipid forming the membrane to disperse them, a method of immobilizing them with a lipid molecule via a covalent bond, or the like is desirable.

(Operation) As an example, a functional film containing two kinds of substances A and B that perform photoreactions with light having wavelengths λ _A and λ _B will be described. A device as shown in FIG. 1 is constructed by using this functional film,
Causes self-sustained pulsation from the functional film. This functional film exhibits an oscillation pattern having a predetermined oscillation frequency, waveform and amplitude when it is not irradiated with light. When this functional film is irradiated with light of wavelength λ _A , the substance B does not react, the substance A undergoes a chemical reaction and its molecular structure or electronic structure is changed, and the oscillation frequency, waveform and amplitude are changed accordingly. An oscillation pattern occurs. When the functional film is irradiated with light of wavelength λ _B , the substance A
Does not react and the substance B causes a chemical reaction to give a structural change different from the change of A to the film, so that an oscillation pattern different from the oscillation pattern when the light of wavelength λ _A is irradiated.

On the other hand, by blocking the light of wavelength λ _A or λ _B , or by irradiating with light that causes a reverse reaction of each chemical reaction, each chemical substance returns to its original state and interacts with the lipid molecule. Since the action also returns to the original state, each oscillation pattern has the same form as before the reaction.

Further, when the light having the wavelength λ _{A and} the light having the wavelength λ _B are simultaneously irradiated, the oscillation pattern and the wavelength λ when the light having the wavelength λ _A is irradiated, depending on the types of the chemical reaction substance and the lipid molecule used. There is a case where an oscillation pattern in the form of the sum of the oscillation patterns when the light of _B is irradiated occurs, and a case where an oscillation pattern which is completely different from the both occurs, but in both cases, when the single light is irradiated. The oscillation pattern will be different.

Although the above-mentioned example is the case where two kinds of chemical substances are added, by adding a larger number of chemical species, it is possible to detect even external information having higher multiplicity.

The functional film of the present invention having a self-oscillation function has an oscillation pattern by causing an active chemical reaction in two or more kinds of reactants in the film in accordance with the wavelength-dimensional multiplicity of light. Since the change occurs, the multiplex information can be detected and identified with high accuracy.

(Example) Hereinafter, the Example of this invention is described in detail.

Add 2 mol% of 1'-octadecyl-3 ', 3'- to a porous filter made of acetyl cellulose with a pore size of 8 μm.
Dimethyl-6-nitrospiro (2H-1-benzopyran-2 ',
2'-Indoline) and 4'-octylazobenzene-4-
A functional film was prepared by stacking dioleoyl phosphate films containing oxybutyric acid.

As shown in FIG. 1, this functional film was attached to a partition wall 2 that divides the inside of the container 1 into two chambers, and KCl of 0.1 molar concentration was provided in one chamber.
The solution and a 0.001 molar KCl solution were placed in the other chamber and kept at 25 ° C. Then, a constant current of about 1 × 10 ⁻⁷ A / cm ² was applied between the solutions through the current application electrodes 5a and 5b, and the membrane potential measuring electrodes 7a and 7b immersed in the KCl solutions 4a and 4b were measured.
The oscillation pattern was observed by the electrometer 8 connected to.

The functional film has a frequency of 2.0 Hz when it is not irradiated with light.
The oscillation pattern is shown. When this functional film was irradiated with light having a wavelength of 280 nm, the oscillation pattern changed to a frequency of 3.5 Hz. Next, it was observed that, when light having a wavelength of 580 nm was irradiated instead of light having a wavelength of 280 nm, the oscillation frequency returned to the original frequency. Further, when the functional film was irradiated with light having a wavelength of 380 nm, the oscillation pattern changed to a frequency of 2.8 Hz. Next, when light with a wavelength of 450 nm was irradiated instead of light with a wavelength of 380 nm, it was observed that the oscillation frequency returned to the original frequency. Such a phenomenon corresponds to the photoisomerization reaction of each compound used.

Note that the change in the oscillation frequency described above is due to the temperature change (± 0.1
It was hardly affected by the external vibration.

[Effects of the Invention] As described above in detail, the functional film having the self-oscillation function of the present invention is active in two or more kinds of reactive substances in the film in accordance with the wavelength-dimensional multiplicity of light. By causing a chemical reaction, it is possible to cause a change in the oscillation pattern. Therefore, by using light of different wavelengths as information (signal), information can be converted with high sensitivity and good reproducibility, and multiplex information can be detected and identified with high accuracy.

[Brief description of drawings]

FIG. 1 is a sectional view showing an apparatus for observing an oscillation phenomenon of a functional film according to the present invention, and FIG. 2 is a characteristic diagram showing an example of an oscillation pattern of the functional film according to the present invention. 1 ... Container, 2 ... Partition wall, 3 ... Functional film, 4a, 4b ... KCl solution, 5
a, 5b ... Current applying electrodes, 6 ... Power supply, 7a, 7b ... Current applying electrodes, 8 ... Electrometer.

Claims (1)

[Claims] 1. A bilayer membrane comprising lipid molecules as a main component, a lipid molecule membrane accumulated on a porous membrane or a polymer membrane in which lipid molecules are dispersed, and two aqueous solutions are divided into two chambers. In the functional film having self-excited oscillation effect due to the difference in ion concentration between aqueous solutions, the change in external pressure, and the application of external DC voltage, different chemical reactions are selectively caused by light of different wavelengths in the film containing the lipid molecule. A functional film having a self-sustained pulsation action, which is characterized by containing two or more kinds of substances to be produced.