Conductive carbon paste for flexible pressure sensor, preparation method thereof, and pressure sensor

Abstract

The invention relates to a conductive carbon paste for a flexible pressure sensor, a preparation method thereof, and a pressure sensor. In terms of mass percentage, the raw material formula of the conductive carbon paste includes the following components: 1-25% of graphene, 0.04% of carbon nanotube ~1.5%, dispersant 0.001~1%, oleoresin 5~45%, thickener 1~10%, coupling agent 0.01~5%, first solvent 25~70% and second solvent 20~40%. The conductive carbon paste of the present invention adds graphene sheets and a small amount of carbon nanotubes to the resin system, and cooperates with the use of dispersants, coupling agents and plasticizers, so that the prepared conductive carbon paste has high sensitivity and high stability , low minimum detection limit, bending resistance, strong adhesion with flexible substrates, etc. Under the action of pressure, the conductive network formed by graphene and carbon nanotubes in the cured conductive carbon paste resin system changes, and the cured conductive carbon paste has increased resistance, high pressure sensitivity, and small pressure changes can be sensed.

Description

technical field [0001] The invention belongs to the technical field of conductive carbon paste for flexible pressure sensors, and in particular relates to a conductive carbon paste for flexible pressure sensors, a preparation method and a pressure sensor. Background technique [0002] The flexible pressure sensor has good flexibility, ductility, and can even be bent or folded freely, and its structure is flexible and diverse. It can be arranged arbitrarily according to the requirements of the measurement conditions, and can detect complex measured objects very conveniently. Flexible pressure-sensitive materials are the key factors in the development of flexible pressure sensor technology. At present, the sensitive materials in flexible pressure sensors have problems such as poor stability, low sensitivity, high minimum detection limit, poor bending resistance, and insufficient adhesion to flexible substrates. [0003] For example, Chinese patent CN109785995A provides a kind...

AI Technical Summary

Problems solved by technology

At present, the sensitive materials in flexible pressure sensors have problems such as poor stability, low sensitivity, high minimum detection limit, poor bending resistance, and insufficient adhesion to flexible substrates.

[0003] For example, Chinese patent CN109785995A provides a kind of porous conductive paste for preparing flexible piezoresistive sensors. The porous conductive paste is prepared by using a sacrificial template with adjustable particle size, which increases the nanopore or micron size of the conductive paste after film formation. The number of holes, under the action of stress, the conductive particles around the holes contact each other, which effectively reduces the conductivity of the material, thereby synergizing with the conductive particles to improve the sensitivity of the flexible piezoresistive sensor. However, its stability and bending resistance are unknown and need to be investigated

[0004] Chinese patent CN104262967A discloses a sensitive material used in pressure sensors. The sensitive material has good stability and sensitivity, but its bending resistance is not involved and needs to be investigated

[0005] Chinese patent CN104558701A uses a new assembly method to prepare a graphene superelastic macroscopic material with a specific layered microstructure. The material has good mechanical resilience and pressure sensitivity. The adhesion is unknown, to be tested

However, this conductive paste is developed for electrode materials, and does not involve pressure sensitivity and bending performance at all, and from the perspective of the formula of the conductive paste, the conductive paste is not suitable for the preparation of flexible pressure sensors.

[0007] In summary, the current sensitive materials in flexible pressure sensors have problems such as poor stability, low sensitivity, high minimum detection limit, poor bending resistance, or insufficient adhesion to flexible substrates.

For example, some materials have high sensitivity, but poor bending resistance; some materials have good bending resistance, but low sensitivity or stability

At present, there is no material that can well meet the comprehensive performance requirements of stability, sensitivity, bending resistance, low minimum detection limit, and good adhesion to flexible substrates.

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