阅读说明：本技术 一种基于薄膜的电容式温度传感器及其制作方法 (Film-based capacitive temperature sensor and manufacturing method thereof ) 是由 吴进 吴子轩 于 2020-05-21 设计创作，主要内容包括：本发明涉及温度传感器领域,更具体地,涉及一种基于薄膜的电容式温度传感器及其制作方法,包括有配合在一起的绝缘衬底和绝缘覆盖层,所述绝缘衬底和绝缘覆盖层之间设有敏感薄膜、电极。本发明能提高可拉伸传感器的灵敏度、响应速度、适用温度范围并兼具透明性,进而实现极端温度环境测试和人体运动情况实时监测。(The invention relates to the field of temperature sensors, in particular to a film-based capacitive temperature sensor and a manufacturing method thereof. The invention can improve the sensitivity, response speed and applicable temperature range of the stretchable sensor and has transparency, thereby realizing the extreme temperature environment test and the real-time monitoring of the human motion condition.)

1. A capacitive temperature sensor based on a film is characterized by comprising an insulating substrate (1) and an insulating covering layer (4) which are matched together, wherein a sensitive film (2) and an electrode (3) are arranged between the insulating substrate (1) and the insulating covering layer (4).

2. The thin film based capacitive temperature sensor according to claim 1, characterized in that the insulating substrate (1) acts as a transparent protective layer.

3. The thin-film based capacitive temperature sensor according to claim 1, characterized in that the sensitive thin film (2) is used as a layer of temperature sensitive material.

4. The film-based capacitive temperature sensor according to claim 1, wherein the sensing film (2) is a polyacrylamide/carrageenan double network hydrogel film.

5. The film-based capacitive temperature sensor of claim 4, wherein the hydrogel film is treated with a saline solution.

6. The film-based capacitive temperature sensor of claim 5, wherein the salt solution is lithium bromide.

7. The thin film based capacitive temperature sensor according to claim 1, wherein the insulating substrate (1) and the insulating cover layer (4) employ polydimethylsiloxane or Ecoflex.

8. The thin film based capacitive temperature sensor according to claim 1, wherein the electrode (3) is made of conductive silver paste or graphene or MXenes material.

9. The thin-film based capacitive temperature sensor according to claim 8, characterized in that the electrode (3) is in the same layer as the sensitive thin film (2) with respect to the insulating substrate (1).

10. A method for manufacturing a film-based capacitive temperature sensor is characterized by comprising the following steps:

s1: carrying out silanization treatment on the quartz glass substrate (5) by adopting hexamethyldisilazane (6);

s2: spin-coating unpolymerized polydimethylsiloxane on the silanized quartz glass substrate (7), and heating and polymerizing to obtain an insulating substrate (1);

s3: carrying out Plasma process treatment on the insulating substrate (1) after the step S2, spin-coating an acrylamide/carrageenan solution (8), introducing an antifreeze salt solution, and sequentially carrying out low-temperature-ultraviolet or ultraviolet-low-temperature polymerization to obtain a polymerized antifreeze hydrogel film layer;

s4: cutting the obtained hydrogel film to obtain a hydrogel film working area sensitive to temperature and deformation;

s5: depositing conductive silver adhesive or Mxenes solution or graphene solution at two ends of a hydrogel film working area by adopting a brush coating method, and curing at low temperature to obtain an electrode (3);

s6: spin-coating unpolymerized polydimethylsiloxane on the hydrogel film working area obtained by the step S5, and obtaining an insulating covering layer (4) through subsequent heating polymerization;

s7: and (3) peeling off the quartz glass substrate (7) to obtain the film-based capacitive temperature sensor.

Technical Field

The invention relates to the field of temperature sensors, in particular to a capacitive temperature sensor based on a thin film and a manufacturing method thereof.

Background

Flexible and stretchable electronics have been developed and applied in the fields of human-machine interfaces, implantable medical sensors, wearable electronics, artificial body reflex arcs, and the like. In the above application, temperature sensing is a common and necessary part, and the temperature of the skin surface, the surrounding environment and the implanted area can be monitored in real time to help adjust subsequent planning. In general, two strategies, structural design and material innovation, are adopted to achieve flexibility and flexibility of electronic devices: the method comprises the following steps: the structure design of island-bridge, wave, crack and the like, and the nanometer materials such as graphene, carbon nano tubes, MXenes, molybdenum disulfide and the like, liquid metal, hydrogel and the like are used for material innovation. However, due to the complexity and complexity of the structural engineering design and process, the high manufacturing cost of the equipment, the low yield, and the like, the structural innovation becomes a high-threshold solution. On the other hand, it is a challenge that new materials are both biocompatible, long-term stable, inherently stretchable, and compatible with microfabrication processes. In this case, the hydrogel, which is itself stretchable and moldable, becomes a puncture.

Hydrogels are three-dimensional cross-linked network polymers containing a large amount of water. Compared with single-network hydrogel, the double-network hydrogel has been proved to be more excellent in tensile property, toughness and recovery property due to additional crosslinking mode, energy dissipation and network interconnection mode. Since the hydrogel contains abundant water, ions can rapidly diffuse and migrate, so that the hydrogel can be applied to stretchable ion conductors, stretchable temperature sensors and soft robot actuators. However, the tendency to dry and freeze at low temperatures in general environments severely reduces its range of application and long-term durability. The currently reported telescopic temperature sensor can hardly meet the requirements of high sensitivity and real-time monitoring at the same time, especially under an extreme temperature environment.

Disclosure of Invention

In order to overcome the defect that the temperature sensor in the prior art cannot meet the requirements of high sensitivity and real-time monitoring, the invention provides the film-based capacitive temperature sensor and the manufacturing method thereof, so that the sensitivity, the response speed and the applicable temperature range of the stretchable sensor are improved, the stretchable sensor has transparency, and the extreme temperature environment test and the real-time monitoring of the human motion condition are further realized.

In order to solve the technical problems, the invention adopts the technical scheme that: a capacitance type temperature sensor based on a film comprises an insulating substrate and an insulating covering layer which are matched together, wherein a sensitive film and an electrode are arranged between the insulating substrate and the insulating covering layer.

In one embodiment, the insulating substrate serves as a transparent protective layer.

In one embodiment, a sensitive film is used as the temperature sensitive material layer.

In one embodiment, the sensitive film is a polyacrylamide/carrageenan double-network hydrogel film.

Preferably, the hydrogel film is treated with a salt solution.

Preferably, the salt solution is lithium bromide.

In one embodiment, the insulating substrate and the insulating cover layer are made of polydimethylsiloxane or Ecoflex.

In one embodiment, the electrodes are made of conductive silver paste or graphene or MXenes materials.

Preferably, the electrode is in the same layer as the sensitive film with respect to the insulating substrate.

The invention provides a method for manufacturing a film-based capacitive temperature sensor, which comprises the following steps of:

s1: performing silanization treatment on the quartz glass substrate by adopting hexamethyldisilazane;

s2: spin-coating unpolymerized polydimethylsiloxane on the silanized quartz glass substrate, and heating and polymerizing to obtain an insulating substrate;

s3: performing Plasma process treatment on the insulating substrate after the step S2, spin-coating an acrylamide/carrageenan solution, introducing an antifreeze salt solution, and sequentially performing low-temperature-ultraviolet or ultraviolet-low-temperature polymerization to obtain a polymerized antifreeze hydrogel film layer;

s4: cutting the obtained hydrogel film to obtain a hydrogel film working area sensitive to temperature and deformation;

s5: depositing conductive silver adhesive or Mxenes solution or graphene solution at two ends of a hydrogel film working area by adopting a brush coating method, and curing at low temperature to obtain electrodes;

s6: spin-coating unpolymerized polydimethylsiloxane on the hydrogel film working area obtained by the processing of the step S5, and obtaining an insulating covering layer through subsequent heating polymerization;

s7: and (3) peeling off the quartz glass substrate to obtain the film-based capacitive temperature sensor.

Compared with the prior art, the invention has the following advantages:

in the preparation method of the film-based capacitive temperature sensor, the insulating layer and the sensitive layer with uniform thickness can be prepared by only using the spin-coating method for preparing the film, the temperature can be rapidly detected by only one layer of the sensitive layer, and the electrode deposition process does not need expensive equipment and complicated steps, so the structure and the process steps are simple.

Drawings

Fig. 1 is a schematic structural diagram of a thin film based capacitive temperature sensor according to the present invention.

FIG. 2 is a flow chart of a manufacturing process of the thin film based capacitive temperature sensor of the present invention.

Fig. 3 is a graph of optical transmittance of a thin film based capacitive temperature sensor of the present invention.

FIG. 4 is a graph showing the freezing points of hydrogel films of the film-based capacitive temperature sensor of the present invention when different salt solutions are introduced.

FIG. 5 is a graph of the static temperature response of a thin film based capacitive temperature sensor of the present invention.

FIG. 6 is a graph of respiratory rate monitoring for different states of motion for a multi-functional application of the thin film based capacitive temperature sensor of the present invention.

FIG. 7 is a graph of respiratory rate monitoring for different states of motion for a multi-functional application of the thin film based capacitive temperature sensor of the present invention.

In the figure, 1-insulating substrate, 2-sensitive thin film, 3-electrode, 4-insulating cover layer, 5-quartz glass substrate, 6-hexamethyldisilazane, 7-quartz glass substrate.

Detailed Description

The drawings are for illustration purposes only and are not to be construed as limiting the invention; for the purpose of better illustrating the embodiments, certain features of the drawings may be omitted, enlarged or reduced, and do not represent the size of an actual product; it will be understood by those skilled in the art that certain well-known structures in the drawings and descriptions thereof may be omitted. The positional relationships depicted in the drawings are for illustrative purposes only and are not to be construed as limiting the invention.

The same or similar reference numerals in the drawings of the embodiments of the present invention correspond to the same or similar components; in the description of the present invention, it should be understood that if there is an orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", etc. based on the orientation or positional relationship shown in the drawings, it is only for convenience of describing the present invention and simplifying the description, but it is not intended to indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and are not to be construed as limiting the present patent, and the specific meaning of the terms may be understood by those skilled in the art according to specific circumstances.