Research And Design Of Pressure And Strain Sensor Applied To Flexible Electronic Skin

Flexible electronic skin is a electronic device that can imitate the perception function of human skin,and has been widely used in the fields of robotics,intelligent prosthesis,wearable devices,sports health monitoring,etc.In this thesis,the research and design of pressure and strain sensors for flexible electronic skins are carried out by relying on the National Natural Science Foundation's major research project "Man-machine inclusive multimodal sensing software operation theory and application".In response to the new requirements in the current application field,how to improve the sensitive characteristics of sensors has been studied and discussed,and the following research results have been achieved:Firstly,the current research status of flexible sensors at home and abroad(including sensor design principles,structural materials,preparation processes,etc.)is elaborated and summarized.A sensitive layer matrix composed of multi-walled carbon nanotubes with excellent electrical conductivity and polydimethylsiloxane film with pyramid microstructure on the surface is proposed based on self-assembly technology.By changing the electrode installation position of the sensitive layer substrate,a flexible resistive pressure sensor capable of sensing the tactile pressure intensity and a flexible strain sensor sensing the degree of bending strain are prepared.Secondly,the optimization of sensor sensitivity has been completed,and the optimal number of self-assembled layers for preparing the sensor's sensitive layer film is determined to be 10 layers.Through experimental comparison,it is proved that the microstructured design on the surface of the sensitive layer can significantly improve the sensitivity of the sensor,which is 40 times that of the sensor without microstructure.The sensor performance test platform is built,and the static and dynamic performance test of the flexible pressure sensor and the tensile strain performance test of the flexible strain sensor are completed.The sensitivity of the pressure sensor in the effective pressure range of 0-4kPa is up to-2.65kPa-1,the response time is 80ms,and the minimum pressure detection limit is 90Pa.The sensitivity of the strain sensor is up to 83.97,and the effective strain range is 0-65%.Finally,a signal acquisition and feedback system based on multi-flexible sensors are built.The system consists of smart gloves,signal acquisition,processing and transmission hardware circuits and a feedback display interface of the host computer;The designed signal feedback system is successfully applied to the movement of human grasping objects,and realized the signal feedback of the flexible electronic skin to the external pressure tactile strength and the degree of angular joint bending.