Development method of flexible pressure-sensitive element based on carbon nano-tube filled high polymer composite material

Abstract

The invention relates to a development method of a flexible pressure-sensitive element based on a carbon nano-tube filled high polymer composite material, which belongs to the technical field of sensors. The method comprises the following steps of: 1. pressure-sensitive material preparation: dispersing carbon nano-tubes into polydimethylsiloxane by utilizing ultrasonic vibration and mechanical stirring methods, and preparing a thin and flexible pressure-sensitive material by using tetraethoxysilane as a crosslinking agent and dibutyltin dilaurate as a catalyst with a spin coating method; 2. pressure-sensitive element packaging, wherein a two-stage sandwich structure is adopted, the first-stage sandwich structure comprises two layers of packaging films and the pressure-sensitive material positioned in the middle; and in the second-stage sandwich structure, each layer of packaging film comprises two layers of polyimide films as well as a copper foil electrode and a lead which are embedded in the two layers of polyimide films. The pressure-sensitive element developed by the invention has good flexibility, high precision, thin thickness, simple process and low cost and is applicable to the fields of pressure monitoring of structures between narrow curved surface layers in the fields of military industry and civil use and artificial electronic skin development and the like.

Description

technical field [0001] The invention belongs to the technical field of sensors, and in particular relates to a preparation and packaging process of a flexible pressure sensor sensitive material. Background technique [0002] In order to ensure the safe operation of major equipment in the fields of aerospace, national defense and military, and obtain system status information in a timely manner, it is necessary to monitor the interlayer pressure in real time. However, in engineering practice, many devices have small interlayer gaps and complex surface shapes. Therefore, a thin and flexible sensor capable of monitoring interlayer pressure is urgently needed. [0003] Conductive polymer composite material is a new type of functional material, which has both flexibility and piezoresistive effect. Therefore, this composite material can be used as a sensitive material for flexible pressure sensors. At present, many scientific research institutions are working on the development...

AI Technical Summary

Problems solved by technology

Since then, the flexible tactile sensor developed by the University of Alberta in Canada using conductive rubber as a sensitive material can be used to analyze the distribution of large-area contact force, but it cannot measure the magnitude of the contact force.

In 2004, Japanese scientific research institutions (Makoto Shimojo, Akio Namiki, Masatoshi Ishikawa, Ryota Makino, and Kunihiko Mabuchi. A Tactile Sensor Sheet Using Pressure Conductive Rubber With Electrical-Wires Stitched Method. IEEE Sensors Journal, 2004; 4(5): 589-596) developed a flexible tactile sensor based on conductive rubber. They used gold-plated metal wires to sew on the surface of sensitive materials as electrodes, which solved the shortcomings of traditional packaging methods, but this method is difficult to operate and expensive. , the total thickness of the sensitive unit after packaging is 500 microns, which cannot meet the stress measurement requirements when the gap is less than 200 microns

In 2005, Tsinghua University used carbon black as the conductive phase to develop a flexible pressure sensor based on carbon black-filled polymer composite materials, but there are still physical connections between the sensitive points of the array sensor package, and there is mutual interference

However, the above literature only studies composite materials from the perspective of characteristic mechanism, and does not conduct research from the perspective of developing thin flexible pressure sensitive elements.

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