阅读说明：本技术 一种柔性可拉伸温控导体绝缘体可逆转变材料及其应用 (Flexible stretchable temperature-controlled conductor-insulator reversible transition material and application thereof ) 是由 汪鸿章 刘静 于 2019-01-21 设计创作，主要内容包括：本发明涉及一种柔性可拉伸温控导体绝缘体可逆转变材料及其应用。所述柔性可拉伸温控导体绝缘体可逆转变材料包括：液态金属、柔性基料；所述液态金属与柔性基料的体积比为1：(0.15-10)。所述材料具有如下优势：制备方法简单,电阻变化范围大,响应速度快、可重复性好,可拉伸性强(780％),可以3D打印。所述材料可在诸多领域都有着很广泛的应用,如将该材料进一步制作成柔性温度开关、温度传感器、可拉伸半导体、阻变式存储器,低温自动保护装置。(the invention relates to a flexible stretchable temperature-controlled conductor insulator reversible transition material and application thereof. The flexible stretchable temperature-controlled conductor-insulator reversible transition material comprises: liquid metal, flexible base stock; the volume ratio of the liquid metal to the flexible base material is 1: (0.15-10). The material has the following advantages: the preparation method is simple, the resistance change range is large, the response speed is high, the repeatability is good, the stretchability is strong (780%), and the method can be used for 3D printing. The material can be widely applied to various fields, such as a flexible temperature switch, a temperature sensor, a stretchable semiconductor, a resistance change type memory and a low-temperature automatic protection device.)

1. A flexible stretchable temperature controlled conductor-insulator reversible transition material comprising: liquid metal, flexible base stock; the volume ratio of the liquid metal to the flexible base material is 1: (0.15-10).

2. the flexible stretchable temperature controlled conductor-insulator reversible transition material of claim 1, wherein the volume ratio of the liquid metal to the flexible base material is 1: (0.25-4), preferably 1: (1-2), more preferably 1: 1.5.

3. the flexible stretchable temperature-controlled conductor-insulator reversible transition material according to claim 1 or 2, wherein the liquid metal is selected from low melting point liquid metals.

4. The flexible stretchable temperature controlled conductor-insulator reversible transition material of claim 3, wherein the liquid metal is selected from one or more combinations of gallium-based alloys, indium-based alloys, or bismuth-based alloys.

5. A flexible stretchable temperature controlled conductor-insulator reversible transition material according to any one of claims 1 to 4, wherein said flexible base material comprises silica gel and/or viscous liquid.

6. The flexible stretchable temperature-controlled conductor-insulator reversible transition material according to claim 5, wherein the silica gel is selected from flexible silica gel, preferably one or more of polydimethylsiloxane, AB gel, polymethylvinylsiloxane or polymethylhydrogensiloxane;

And/or the viscous liquid is selected from silicone oil and glycerol.

7. A method for preparing the flexible stretchable temperature-controlled conductor-insulator reversible transition material as claimed in any one of claims 1 to 6, comprising: mixing silica gel and liquid metal, stirring, pouring and curing to obtain the product.

8. The method for preparing the flexible stretchable temperature-controlled conductor-insulator reversible transition material according to claim 7, wherein the stirring conditions are as follows: the speed is 600-650r/min, the stirring time is 60-180s, and the more preferable time is 120 s;

And/or the curing time is not less than 10 min.

9. Use of the flexible stretchable temperature-controlled conductor-insulator reversible transition material according to any one of claims 1 to 6 or the flexible stretchable temperature-controlled conductor-insulator reversible transition material prepared by the method according to claim 7 or 8 in the field of flexible electronics;

Preferably, the flexible electronics are an automatic starting device, an automatic alarm device, a flexible temperature switch, a temperature sensor, a stretchable semiconductor and a resistive random access memory.

10. A method of using the flexible stretchable temperature controlled conductor-insulator reversible transition material according to any one of claims 1 to 6 or the flexible stretchable temperature controlled conductor-insulator reversible transition material prepared by the method according to claim 7 or 8, comprising: the material achieves reversible transition of a conductor and an insulator by adjusting the ambient temperature; the adjusting mode is preferably a low-temperature refrigerator, liquid nitrogen and dry ice.

Technical Field

The invention belongs to the field of conductor-insulator conversion materials, and particularly relates to a flexible stretchable temperature-controlled conductor-insulator reversible conversion material and application thereof.

Background

Materials that change conductivity by temperature have found wide application in many fields, such as smart switches, sensors, semiconductors, resistive random access memories. The traditional temperature control conductor insulator transition material comprises a mott insulator, a metal oxide, perovskite, an organic membrane and the like, is basically made of solid rigid materials, has no flexibility and stretchability, and cannot bear stretching, bending and deformation, so that the application of the temperature control conductor insulator transition material in the fields of flexible electronics, wearable electronics directly interacting with people and the like is limited.

In order to improve the flexible and stretchable performance of the traditional temperature control conductor-insulator transition material, researchers mix some filling materials with materials such as flexible silica gel; the filling material mainly comprises carbon nanotubes, graphene, solid metal particles and the like, but the obtained composite material has the following defects: small resistance change range, resistance change only by pressure stimulation, poor stretchability, complex manufacturing process and the like.

In view of the above, the present invention is particularly proposed.

Disclosure of Invention

In order to solve the technical problems, the invention particularly provides a flexible, stretchable, temperature-controlled Conductor-Insulator reversible Transition (TIC) material based on liquid metal. The material is prepared by uniformly stirring liquid metal and flexible base material in a specific ratio, and the preparation process is simple. The material has the characteristics of large resistance change range, high response speed, good repeatability, strong stretchability, capability of 3D printing and the like, and can be widely applied to various fields.

The technical scheme of the invention is as follows:

A flexible stretchable temperature-controlled conductor-insulator reversible transition material based on liquid metal comprises liquid metal and a flexible base material; the volume ratio of the liquid metal to the flexible base material is 1: (0.15-10); the preferred volume ratio is 1: (0.25-4), and more preferably 1: (1-2), more preferably 1: 1.5. Tests prove that when the volume ratio of the liquid metal to the flexible base material reaches 1:1.5, the reversible transformation performance of the obtained material is superior to that of other ratios. When the ratio is lower than the above ratio, the two are difficult to be uniformly mixed, and the response speed of the conductor recovered to the insulator is reduced in the same ratio; when it is higher than this ratio, it is difficult to achieve a reduction in transition from the insulator to the conductor.

The liquid metal is selected from low melting point liquid metals, preferably one or more of gallium-based alloy, indium-based alloy or bismuth-based alloy, such as GaIn _24.5, Ga.

The flexible base material comprises silica gel and/or viscous liquid, and the flexible base material is used as an insulating shell for wrapping liquid metal to realize automatic transformation of the conductor insulator.

the silica gel is selected from flexible silica gel, preferably one or more of Polydimethylsiloxane (PDMS), AB (Ecoflex), polymethylvinylsiloxane or polymethylhydrogensiloxane.

The viscous liquid is selected from silicone oil, glycerol, etc.

The invention also provides a preparation method of the flexible stretchable temperature-controlled conductor-insulator reversible transition material based on the liquid metal, which comprises the following steps: mixing liquid metal and silica gel, stirring, pouring and curing to obtain the product.

Research shows that in the mass proportion range, the mixing and stirring time has substantial influence on the conductive transformation effect; the stirring conditions are determined by tests as follows: the speed is 600-650r/min, the stirring time is 60-180s, and more preferably 120s, and the reversible transformation performance of the conductor insulator of the obtained material is better under the condition; if the stirring time is too long, for example, more than 180s, the material cannot realize the conduction transformation phenomenon at low temperature. As shown in fig. 1.

During the curing process, accelerated curing can be achieved by heating, or a retarder can be added to increase the curing time. However, if the curing time is less than 10 minutes, it is difficult to obtain a conductor-insulator reversible transition material.

The invention also provides application of the flexible stretchable temperature control conductor insulator reversible transition material based on the liquid metal in the field of flexible electronics, wherein the flexible electronics can be an automatic starting device, an automatic alarm device, a flexible temperature switch, a temperature sensor, a stretchable semiconductor, a resistance change type memory and the like. The reversible transition material of the conductor insulator can bear large temperature span and can be applied to extreme environments such as outer space, mars, moon and other regions with large temperature transition.

The invention also provides a use method of the flexible stretchable temperature-controlled conductor insulator reversible transition material, which comprises the following steps: the conductor/insulator reversible transition is stimulated by changing the temperature (low/high). Specifically, the low-temperature adjusting mode is a low-temperature refrigerator, liquid nitrogen, dry ice and other means; the high-temperature adjusting mode comprises a heating plate, hot water, a heating gun and the like. For example, the material behaves as a conductor at low temperatures and as an insulator at room temperature or at elevated temperatures.

Compared with the prior art, the invention has the following beneficial effects:

The reversible transition material is an insulating material at room temperature, is instantaneously transformed into a conductor under low-temperature induction, the resistance change exceeds 10 ⁹ times, and the transformation of the conductor insulator is reversible, and the conductor insulator is not obviously damaged in structure and the conductivity is not reduced after being repeated for hundreds of times.

The material obtained by the invention has the characteristics of strong stretchability (780%), large resistance change range (10 ⁹), high temperature control response speed (3 seconds), good reversible repeatability of resistance change (more than 1000 times), simple preparation process (simple mixing) and 3D printing.

Drawings

FIG. 1 is a graph showing the effect of stirring time on the performance of the reversible transformation material of the present invention.

Figure 2 the principle of operation of the stretchable temperature control switch described in embodiment 1.

fig. 3 shows the working principle of the temperature display device according to embodiment 4.

Detailed Description

The flexible stretchable temperature-controlled conductor-insulator reversible transition material provided by the invention is prepared by mixing liquid metal and a flexible material in a specific ratio. Only within this specific range of ratios will the claimed performance characteristics be achieved.

Under the condition of room temperature, the liquid metal has the liquidity of liquid and the electric and thermal conductivity of metal, and meanwhile, the phase change of the liquid metal can generate larger volume change, so that the liquid metal can be used as a good raw material for preparing a flexible conductor insulator transition material.