Microstructure flexible capacitance pressure sensor based on polydimethylsiloxane

Abstract

The utility model belongs to the technical field of sensor detection, and particularly relates to a micro-structure flexible capacitive pressure sensor based on polydimethylsiloxane. The utility model discloses a micro-structure flexible capacitance pressure sensor based on polydimethylsiloxane. The micro-structure flexible capacitance pressure sensor comprises an upper flexible micro-structure packaging layer, a first electrode layer, a dielectric layer, a second electrode layer and a lower flexible micro-structure packaging layer which are attached from top to bottom. The flexible pressure sensor has the advantages that the flexible pressure sensor is prepared by adopting a preparation technology of a multi-layer composite structure, and the flexible pressure sensor has the advantages of high sensitivity, ultra-thin and ultra-light performance, compressibility, simple process, easiness in array manufacturing and high applicability. And the pressure sensor is beneficial to sensing and transmission of pressure, and the stability and reliability of the sensor are ensured while the sensitivity is improved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to sensor detection technical field especially relates to a kind of microstructure flexible capacitive pressure sensor based on polydimethylsiloxane. BACKGROUND

[0002] With the development of science and technology, capacitive pressure sensor is more and more widely used in medical, industrial, consumer electronics and other fields, however, traditional capacitive pressure sensor has deficiencies in sensitivity, flexibility, linearity and conductivity, etc., and it is difficult to meet the needs of current applications. Therefore, it is of great significance in the field to develop a capacitive pressure sensor with high sensitivity, good flexibility and strong conductivity. SUMMARY

[0003] The utility model provides a kind of microstructure flexible capacitive pressure sensor based on polydimethylsiloxane, specific scheme is as follows.

[0004] A kind of microstructure flexible capacitive pressure sensor based on polydimethylsiloxane, characterized by: including from top to bottom adhering upper layer flexible microstructure encapsulation layer, first electrode layer, dielectric layer, second electrode layer and lower layer flexible microstructure encapsulation layer.

[0005] The pressure sensor is flexible and compressible structure as a whole, the upper layer flexible microstructure encapsulation layer is a polydimethylsiloxane film with pyramid structure, which is tightly adhered to the first electrode layer by its own biological adhesion; the lower layer flexible microstructure encapsulation layer is tightly adhered to the lower surface of the first electrode layer and the upper surface of the second electrode layer by its own biological adhesion.

[0006] Preferably, the first electrode layer and the second electrode layer are both graphene electrode layers.

[0007] Graphene, as a conductive electrode, has excellent conductivity and mechanical strength, which improves the performance of the sensor.

[0008] Preferably, the dielectric layer is a microporous compressible dielectric layer.

[0009] Preferably, the upper layer flexible microstructure encapsulation layer is a polydimethylsiloxane film with pyramid structure.

[0010] Preferably, the lower layer flexible microstructure encapsulation layer is a cylindrical microstructure polydimethylsiloxane film.

[0011] Pyramid structure has high sensitivity and good stability, and is suitable for application scenarios that require high sensitivity and stability. Cylindrical microstructure has high compressibility and appropriate rigidity, and is not easy to collapse, thereby realizing high sensitivity and stability of the flexible resistance sensor.

[0012] Preferably, the upper and lower flexible micro-structure encapsulation layers are prepared by spin-coating a flexible polymer in a corresponding micro-structure mold, followed by heating and curing, and then adhering to the surface of the electrode layer connected thereto; the flexible polymer is polydimethylsiloxane with a thickness of 1-3 mm.

[0013] The upper and lower flexible micro-structure encapsulation layers are prepared by spin-coating a flexible polymer in a corresponding micro-structure mold, followed by heating and curing, and then adhering to the surface of the electrode layer connected thereto; the flexible polymer is polydimethylsiloxane with a thickness of 1-3 mm.

[0014] Preferably, the microporous compressible dielectric layer is a polydimethylsiloxane flexible elastomer with a microporous structure prepared by a sacrificial template method, and the microporous compressible dielectric layer has a thickness of 5-10 mm.

[0015] The main material in the microporous compressible dielectric layer is polydimethylsiloxane with a thickness of 5-10 mm, and the upper and lower surfaces thereof are respectively attached to the first electrode layer and the second electrode layer; the microporous compressible dielectric layer is a polydimethylsiloxane flexible elastomer with a microporous structure prepared by a sacrificial template method, and is prepared by leaving pores in polydimethylsiloxane using a sacrificial template method. Under the action of pressure, the pores in the microporous compressible dielectric layer are compressed, and the air or solution therein is discharged, resulting in an increase in the dielectric constant of the entire sensor and a decrease in the distance between the two electrodes due to the deformation of the flexible microporous compressible dielectric layer, thereby increasing the relative change in the capacitance of the capacitive sensor and further improving the sensitivity of the pressure sensor.

[0016] Preferably, the graphene electrode layer is a flexible film material layer with a surface having graphene, which is prepared by mixing PI powder and polydimethylsiloxane and then laser induction; the electrode layer thickness of the first electrode layer and the second electrode layer is 1-3 mm.

[0017] The graphene electrode layer material is a flexible film material layer with a surface having graphene, which is prepared by mixing PI powder and polydimethylsiloxane and then laser induction, and PI is polyimide; the electrode layer thickness of the first graphene electrode layer and the second graphene electrode layer is 1-3 mm; the two electrode layers are tightly attached to the upper and lower surfaces of the microporous compressible dielectric layer, and the two electrode layers form a capacitive structure unit with the flexible microporous compressible dielectric layer, which is used to measure the capacitance value and its change between the upper and lower electrodes, and the pressure can be detected according to the capacitance value and its relative change.

[0018] The utility model advantages lie in: through adopting the preparation technology of multilayer composite structure preparation this flexible pressure sensor, have high sensitivity, ultrathin ultralight, compressibility, simple process, easily arrayed manufacturing and application strong advantage. And this pressure sensor is favorable to the perception and transmission of pressure, improve the sensitivity while ensuring the stability and reliability of the sensor. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 It is structural drawing of the utility model;

[0020] Figure 2 It is the enlarged view of microporous compressible dielectric layer;

[0021] Figure 3 It is the enlarged view of upper layer flexible microstructure encapsulation layer;

[0022] Figure 4 It is the enlarged view of lower layer flexible microstructure encapsulation layer.

[0023] Reference signs: 1-upper layer flexible microstructure encapsulation layer, 2-first graphene electrode layer, 3-microporous compressible dielectric layer, 4-second graphene electrode layer, 5-lower layer flexible microstructure encapsulation layer. DETAILED DESCRIPTION

[0024] Example 1

[0025] This embodiment discloses a kind of based on polydimethylsiloxane microstructure flexible capacitive pressure sensor, including from top to bottom adhering upper layer flexible microstructure encapsulation layer 1, first graphene electrode layer 2, microporous compressible dielectric layer 3, second graphene electrode layer 4 and lower layer flexible microstructure encapsulation layer 5;

[0026] Wherein, upper layer flexible microstructure encapsulation layer 1 is the polydimethylsiloxane film with pyramid structure;Lower layer flexible microstructure encapsulation layer 5 is cylindrical microstructure polydimethylsiloxane film;

[0027] The upper layer flexible microstructure encapsulation layer 1 and lower layer flexible microstructure encapsulation layer 5 are adhered by heating and solidifying after being spin-coated in the mold of corresponding microstructure by flexible polymer;The flexible polymer is polydimethylsiloxane, and the thickness is 3mm.

[0028] The microporous compressible dielectric layer 3 is the polydimethylsiloxane flexible elastomer with microporous structure prepared by using sacrificial template method, and the thickness of microporous compressible dielectric layer 3 is 5mm.

[0029] The graphene electrode layer is a flexible film material layer with graphene surface, which is made of PI powder mixed with polydimethylsiloxane and then induced by laser.

[0030] The capacitor structure unit composed of the first graphene electrode layer 2 and the second graphene electrode layer 4 and the microporous compressible dielectric layer 3 has a capacitance value C0 between the upper and lower electrodes when there is no external pressure. When the upper flexible microstructure packaging layer 1 transmits the pressure to the microporous compressible dielectric layer 3 when the microporous compressible dielectric layer 3 is compressed and deformed under the action of the pressure, the distance between the upper and lower electrodes in the microporous compressible dielectric layer 3 is reduced, the dielectric constant of the dielectric layer is increased, the final capacitance value is increased, and the relative change amount (C1-C0) / C0 of the capacitance is positively correlated with the external pressure F, so that the relative change amount of the capacitance is used to reflect the size of the external contact pressure, wherein C1 is the capacitance value after the pressure is increased.

Claims

1. A polydimethylsiloxane-based microstructured flexible capacitive pressure sensor, characterized by: The application relates to a flexible micro-structure encapsulation layer, which comprises, from top to bottom, an upper layer of flexible micro-structure encapsulation layer (1), a first electrode layer, a dielectric layer, a second electrode layer and a lower layer of flexible micro-structure encapsulation layer (5); the dielectric layer is a microporous compressible dielectric layer (3); the upper layer of flexible micro-structure encapsulation layer (1) is a polydimethylsiloxane film with a pyramid structure; and the lower layer of flexible micro-structure encapsulation layer (5) is a cylindrical micro-structure polydimethylsiloxane film.

2. A microstructured flexible capacitive pressure sensor based on polydimethylsiloxane according to claim 1, characterized in that: The first electrode layer and the second electrode layer are both graphene electrode layers, wherein the electrode layer thickness of the first electrode layer and the second electrode layer is 1-3 mm.

3. The microstructured flexible capacitive pressure sensor based on polydimethylsiloxane according to claim 1, characterized in that: The upper layer of flexible micro-structure encapsulation layer (1) and the lower layer of flexible micro-structure encapsulation layer (5) are prepared by spin-coating a flexible polymer in a corresponding micro-structure mold, heating and curing, and then adhering to the surface of the electrode layer connected thereto; the flexible polymer is polydimethylsiloxane, and the thickness is 1-3 mm.

4. The microstructured flexible capacitive pressure sensor based on polydimethylsiloxane according to claim 1, characterized in that: The microporous compressible dielectric layer (3) is a polydimethylsiloxane flexible elastomer with a microporous structure prepared by using a sacrifice template method, and the thickness of the microporous compressible dielectric layer (3) is 5-10 mm.

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