CN203119810U - Flexible thermoelectric power generation micro-unit structure - Google Patents

Abstract

The utility model discloses a micro-unit structure for flexible thermoelectric power generation. A layer of insulating hard films distributed at equal intervals is deposited on the surface of the polyimide substrate. On both sides of each insulating hard film, there are P-type thin film thermoelectric arms and N Type thin-film thermoelectric arms, one end of each pair of P-type thin-film thermoelectric arms and N-type thin-film thermoelectric arms is connected with a wire, and the other end of the P-type thin-film thermoelectric arm is connected with the other end of the adjacent N-type thin-film thermoelectric arm with a wire, N The other end of the P-type thin-film thermoelectric arm is connected with the other end of the adjacent next P-type thin-film thermoelectric arm by wires to form a flexible thermoelectric power generation micro-unit structure in turn. The utility model has flexibility and can be deformed in multiple directions. When the thermoelectric power generation unit undergoes structural deformation, the insulating hard film can prevent the bismuth telluride thermoelectric material with poor ductility from breaking and avoiding failure. The utility model is mainly aimed at the energy supply of implanted medical micro-device in the body, and has the value of popularization and application.

Description

A flexible micro-unit structure for thermoelectric power generation

technical field

The utility model relates to a temperature difference power generation structure, in particular to a flexible temperature difference power generation micro-unit structure. the

Background technique

Implantable medical devices in the body are used more and more widely, such as cardiac pacemakers, defibrillators, artificial sphincters, implanted drug pumps, etc., which can replace or improve the function of organs or treat certain diseases. Providing durable and stable energy supply for implantable medical devices is a research hotspot and difficult problem in the world today. The existing energy supply mainly relies on lithium batteries, and its effective working time is usually no more than five years. Replacing the batteries requires surgical operations, which brings physical pain to the patients. The rechargeable secondary lithium battery needs external electromagnetic coupling, infrared radiation and other charging, which brings a lot of inconvenience to patients.

In addition, there are some new energy supply methods, such as nuclear batteries, biofuel cells, external electromagnetic coupling energy supply, and thermoelectric power generation. The working life of nuclear batteries can exceed ten years, but they are generally large in size and have toxicity and radiation hazards to the human body; biofuel cells use enzymes or microorganisms as catalysts to convert the chemical energy of biofuels such as glucose into electrical energy, but the power supply life is average Only a few days; power supply by means of electromagnetic induction outside the body needs to carry additional devices outside the body, which will increase the burden on the patient's movement.

Thermoelectric power generation uses the Seebeck effect of thermoelectric semiconductors to convert thermal energy into electrical energy. Because the thermoelectric power generation device has the advantages of no moving parts, no noise, no pollution, simple structure, and easy miniaturization, etc., at the same time, because the body temperature of the normal human body is constant and there is a small temperature difference between the body and the body surface, and the thermoelectric power generation has a great influence on the temperature difference. There is no requirement for the lower limit, therefore, the temperature difference existing in the human body can be used directly to generate electricity.

Existing micro-flexible thermoelectric power generation components usually use flexible connections between bulk micro-thermoelectric materials. The overall volume miniaturization and flexibility of this type of thermoelectric power generation components are relatively limited, and they are not suitable for implanting in the human body as an energy source, because There are many curved surfaces in the internal environment of the human body and the flexibility of human body activities requires a smaller size and better flexibility for the implanted thermoelectric power generation components in the body; some researchers process the thermoelectric semiconductor material slurry on the flexible substrate by MEMS method Structurally, since bismuth telluride materials have a high thermoelectric figure of merit at room temperature, the use of bismuth telluride and its alloys can increase the power generation of thermoelectric power generation devices. However, the mechanical properties of bismuth telluride (BiTe) materials are poor. The bismuth telluride material is relatively brittle, and the Te-Te layer is prone to slip when it is under pressure, which will cause fracture and deformation, so the bismuth telluride and its alloy materials directly processed on the flexible substrate are easy to break, making the thermoelectric power generation unit invalid. Therefore, it is very necessary to develop a thermoelectric power generation micro-unit structure that can reduce impact and have better flexibility.

Contents of the invention

The purpose of the utility model is to provide a flexible thermoelectric micro-unit structure capable of adapting to curved surfaces, simple in process, high in thermoelectric conversion efficiency, high in reliability, and capable of being processed into various thermoelectric generators.

Basic principle of the utility model is:

According to the Seebeck effect, the temperature difference between the P-type and N-type thin-film thermoelectric arms will generate a voltage difference at both ends. Since the voltage generated by a single thermocouple is very low, the method of "parallel connection of heat circuits and series connection of circuits" can be used to connect The thermocouples composed of P-type and N-type thin-film thermoelectric arms are designed and arranged to form single-row or multi-row array thermoelectric modules to increase the output voltage value.

The thermoelectric figure of merit of bismuth telluride material at room temperature is relatively high, and the use of bismuth telluride and its alloys can increase the power generation of thermoelectric power generation devices. However, due to the poor mechanical properties of bismuth telluride (BiTe) materials, the structure of the material is -Te-Bi-Te-Te-Bi-Te-layered structure with van der Waals bonds between Ti-Ti, It is easy to break, so when the bismuth telluride material is under pressure, the Te-Te layer is prone to slip, resulting in fracture deformation. The bismuth telluride material directly processed on the flexible substrate is easy to break and cause the failure of the thermoelectric power generation unit. Therefore, if a layer of insulating hard film is added on the polyimide substrate, the rigidity can be increased and the original shape and structure of the thermoelectric material can be maintained, thereby avoiding the failure of the thermoelectric power generation unit caused by the fracture of the thermoelectric material.

The technical scheme that the utility model solves its technical problem adopts is:

In the utility model, a plurality of insulating hard films distributed at equal intervals are deposited on the surface of the polyimide substrate, and a P-type film parallel to each other and equal in length and thickness is arranged on both sides of each insulating hard film. Thermoelectric arm and one N-type thin film thermoelectric arm, one end of each pair of P-type thin-film thermoelectric arm and N-type thin-film thermoelectric arm is made of conductive silver glue wire, the other end of the P-type thin-film thermoelectric arm is connected to the adjacent N-type thin-film thermoelectric arm The other end of the N-type thin-film thermoelectric arm is connected with the other end of the adjacent P-type thin-film thermoelectric arm with a conductive silver adhesive wire, and the flexible thermoelectric power generation microunit is sequentially formed in the same connection mode. structure.

The material of the insulating hard film is silicon nitride or diamond-like carbon.

The material of the thin film thermoelectric arm is doped bismuth telluride.

The beneficial effect that the utility model has is:

The use of polyimide substrate and conductive silver glue wires makes the structure of the thermoelectric power generation unit flexible and can be deformed in multiple directions. When the structure of the thermoelectric power generation unit is deformed, the insulating hard film can prevent the bismuth telluride thermoelectric material with poor ductility from occurring. Fracture, to avoid the failure of the thermoelectric power generation unit. The invention is mainly aimed at the energy supply of implanted medical micro-device in the body, and has the value of popularization and application.

Description of drawings

Fig. 1 is a structural representation of the utility model.

Fig. 2 is a left side view of Fig. 1 .

Fig. 3 is a schematic diagram of a flexible thermoelectric power generation device in a crimp package of the present invention.

Fig. 4 is a schematic diagram of the planar flexible thermoelectric power generation film after parallel connection of the utility model.

Fig. 5 is a schematic diagram of the folded flexible thermoelectric power generation film in Fig. 4 .

Fig. 6 is a schematic diagram of the flexible thermoelectric power generation device after the package is folded in Fig. 5 .

In the figure: 1. Polyimide substrate, 2. Insulating hard film, 3. P-type thin-film thermoelectric arm, 4. N-type thin-film thermoelectric arm, 5. Conductive silver glue wire, 6. Thermally conductive and insulating polymer packaging layer.

Detailed ways

Below in conjunction with accompanying drawing and embodiment the utility model is described further.

As shown in Fig. 1 and Fig. 2, the utility model deposits a plurality of insulating hard films (5 in Fig. 1) with equidistant distribution on the upper surface of polyimide substrate 1 by PECVD method. There are a P-type thin film thermoelectric arm 3 and an N-type thin film thermoelectric arm 4 parallel to each other and equal in length and thickness on both sides of the hard film 2, each pair of P-type thin film thermoelectric arms 3 and N-type thin film thermoelectric arms 4 One end is connected with a conductive silver glue wire 5, the other end of the P-type thin film thermoelectric arm 3 is connected with the other end of the adjacent N-type thin film thermoelectric arm 4 with a conductive silver glue wire 5, and the other end of the N-type thin film thermoelectric arm 3 is connected with the other end of the N-type thin film thermoelectric arm 4. The other end of the adjacent P-type thin film thermoelectric arm 4 is connected with a conductive silver glue wire 5, and the flexible thermoelectric power generation micro-unit structure is sequentially formed in the same connection manner. The conductive silver glue wire 5 can be made of medium-temperature curing conductive silver glue wire material, and through screen printing processing, conduction and heat insulation can be realized between the conductive silver glue wire 5 and the thermoelectric arm.

The material of the insulating hard film is silicon nitride or diamond-like carbon.

The material of the thin-film thermoelectric arms is doped bismuth telluride and its alloys, the P-type thin-film thermoelectric arms 3 and the N-type thin-film thermoelectric arms 4 are alternately arranged, and the insulating hard film 2 and the thin-film thermoelectric arms can realize heat conduction, insulation.

The micro-unit structure of flexible thermoelectric power generation can be bent into the desired shape, and then packaged with thermally conductive and insulating flexible materials such as PVDF/AlN composite film or epoxy resin composite thermal conductive film to form a thermoelectric power generation device with high energy density. The packaging material used has good biocompatibility.

The P-type thin-film thermoelectric arm 3 and the N-type thin-film thermoelectric arm 4 can be processed on the insulating hard film 2 by means of screen printing, electrochemical deposition, magnetron sputtering and the like. For example, by magnetron sputtering, the P-type thin-film thermoelectric arm 3 and the N-type thin-film thermoelectric arm 4 are processed twice, using corresponding masks. First use photolithography to process the mask plate for sputtering. Positioning holes should be designed on the mask plate to ensure that the sputtering thermoelectric arms are parallel. P-type and N-type thin-film thermoelectric arms are arranged alternately to form thermocouples parallel to each other. Thermal conduction and insulation can be conducted between the insulating hard film and the film thermoelectric arm. The length of the P-type thin film thermoelectric arm 3 and the N-type thin film thermoelectric arm 4 are equal to the length and thickness of the insulating hard film 2 .

As shown in Figure 1 and Figure 3, the flexible thermoelectric power generation micro-unit structure is curled into a disc shape, and is packaged up and down with thermally conductive and insulating flexible materials such as PVDF/AlN composite film or epoxy resin composite thermally conductive film, and 6 is thermally conductive and insulating polymerization The object packaging layer forms a flexible thermoelectric power generation device with high energy density. In Figure 3, the upper end of the flexible thermoelectric power generation device is the hot end, and the lower end is the cold end.

Multiple flexible thermoelectric power generation micro-unit structures are processed in parallel to form a planar flexible thermoelectric power generation film, as shown in Figure 4; after folding, a corrugated flexible thermoelectric power generation film structure is formed, as shown in Figure 5; PVDF/AlN composite film or ring Oxygen resin composite heat-conducting film and other heat-conducting and insulating flexible materials to form a flexible thermoelectric power generation device, as shown in Figure 6, 6 is a heat-conducting and insulating polymer packaging layer; in Figure 6, the upper end of the flexible thermoelectric power generation device is the hot end, and the lower end is the cold end. end. The material and structure of the flexible thermoelectric power generation device are flexible and can fit curved surfaces.

Claims (3)

1. A micro-unit structure for flexible thermoelectric power generation, characterized in that: a plurality of insulating hard films distributed at equal intervals are deposited on the upper surface of the polyimide substrate (1), and each insulating hard film (2) There are a P-type thin-film thermoelectric arm (3) and an N-type thin-film thermoelectric arm (4) parallel to each other and equal in length and thickness on both sides of the top, each pair of P-type thin-film thermoelectric arms (3) and N-type thin-film thermoelectric arms One end of (4) uses a conductive silver glue wire (5), and the other end of the P-type thin film thermoelectric arm (3) and the other end of the adjacent N-type thin film thermoelectric arm (4) use a conductive silver glue wire (5) Connection, the other end of the N-type thin-film thermoelectric arm (3) is connected with the other end of the adjacent P-type thin-film thermoelectric arm (4) with a conductive silver glue wire (5), and the flexible thermoelectric power generation micro cell structure. 2. A micro-unit structure for flexible thermoelectric power generation according to claim 1, characterized in that: the insulating hard film is made of silicon nitride or diamond-like carbon. 3. A micro-unit structure for flexible thermoelectric power generation according to claim 1, characterized in that: the material of the thin-film thermoelectric arm is doped bismuth telluride.

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