Flexible stress sensor and preparation method thereof

Abstract

The present invention relates to a flexible stress sensor. The flexible stress sensor comprises two sensing assemblies; each sensing assembly includes a flexible fiber wire and a nanostructured film coating the flexible fiber wire; the flexible fiber wire is made of a conductive material or the surface of the flexible fiber wire is provided with a conductive layer; the nanostructured film is made of a conductive material or a semiconductor material; the two sensing assemblies are cross-stacked; and the nanostructured films of the two sensing assemblies contact with each other at the intersection of the two sensing assemblies. The present invention also relates to a preparation method of the flexible stress sensor. The flexible stress sensor of the invention has the advantages of small size, high resolution, high sensitivity and simple preparation, is suitable for being applied to miniaturized and integrated equipment and can be used for making wearable equipment for detecting human health.

Description

technical field [0001] The invention relates to the technical field of sensors, in particular to a flexible stress sensor and a preparation method thereof. Background technique [0002] With the advent of the era of wearable electronic products, wearable devices for real-time monitoring of human health status have attracted more and more attention. In wearable devices, the most critical flexible stress sensor related technologies are often mastered in industrially developed countries such as the United States, Japan, and Germany. [0003] In order to break the technical monopoly of foreign countries on high-performance flexible stress sensors, domestic researchers have continuously proposed innovative technologies related to this field, especially using tiny micro-nano structures as sensing materials to improve the sensitivity of flexible stress sensors. At present, some domestic enterprises have been able to produce flexible stress sensors with high sensitivity, but despit...

AI Technical Summary

Problems solved by technology

[0006] (1) Using a whole piece of nanostructured fiber membrane as a resistance strain gauge leads to a relatively large sensor size, which is difficult to apply in miniaturized equipment, and is also not conducive to the detection of small pressures, and the resistance change rate of the sensor does not exceed 0.2%. , the current change in the connected test circuit is only a few tenths of a microampere, and there are problems of insufficient test resolution and low sensitivity;

[0007] (2) The electrodes need to be arranged symmetrically at both ends of the nanostructured fiber membrane, so as to ensure that the whole fiber membrane can sense the pressure uniformly. Integrating multiple sensors into an array and making the individual sensors independent and insulated from each other requires the design of complex circuits and difficult circuit manufacturing processes, which may reduce the overall flexibility and practicability of the sensor array;

[0008] (3) The preparation steps are complicated. First, the PVDF spinning solution must be prepared, and then the PVDF fiber membrane is prepared with a spinning voltage of 10 to 14 kilovolts, and then the polyaniline reaction solution is prepared, and the PVDF fiber membrane is soaked in the polyaniline reaction solution. Then take it out and dry it to get the nanostructured polyaniline coaxial fiber membrane, and finally install the electrode and PDMS film to complete the assembly of the sensor. The whole preparation process uses a lot of reagents, many steps, many equipments, and harsh spinning conditions. , so the cost of this sensor is high

[0009] Therefore, the current technical development of flexible stress sensors is not yet mature, and there is still much room for improvement.

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