Design And Experimental Study Of Resistive Wearable Flexible Mechanical Sensor

In the wake of developments in science and technology,the study of flexible mechanical sensors has become more and more extensive.Flexible mechanical sensors are mainly used in electronic skin and intelligent robots.Electronic skin is used to model various functions of human skin.A flexible sensor is attached to the surface of the carrier to detect changes in temperature,humidity and pressure.The electronic skin with ultra-high sensitivity can measure the vibration of the muscles of the human body,such as pulse,breathing and throat,and then transfer the data to the user's mobile phone through bluetooth and other devices to monitor the measured objects.The biggest problem encountered in the study of flexible mechanical sensors is that they cannot be produced in large scale,due to its high cost,complicated processes,confused signal output and low sensitivity.In recent years,researchers have endeavored to produce highly sensitive flexible mechanical sensors in various ways,but the effect is not obvious.In this thesis,two flexible mechanical sensors are proposed to solve the aforementioned challenges.This thesis includes the in-principle analysis,the introduction of the manufacturing process and the research on various sensing properties of the sensors.The presentation of this thesis mainly elaborates through the following aspects:?1?A wearable flexible mechanical sensor with highly sensitive functions.By preparing a type of special graphene oxide-coated sodium chloride powder as a pore-forming agent,the oxidized carbon nanotube solution is repeatedly immersed:by self-assembly,the oxidized carbon nanotubes may adhere to graphene oxide and polydimethylsiloxane?PDMS?.The surface of the porous structure forms a mechanical sensor with oxidized carbon nanotubes,graphene oxide and PDMS composite.According to the obtained experimental results,the sensor has high sensitivity,can accurately identify and distinguish between forward pressure and tangential friction:the resistance change rate in the range of 0³.8 kPa forward pressure is-0.13 kPa^-1.And when the resistance changes in the range of 3.8⁶.3 kPa,the rate is-0.03 kPa^-1.The minimum detectable pressure is less than 25 Pa.The sensor exhibits a highly reproducible response after bending and shearing for 5000 cycles,and it has super-hydrophobic properties,and can be used in many applications.?2?Experimental study on wearable flexible mechanical sensors based on non-woven fabrics.The pleated elastic nonwoven fabric was repeatedly immersed in the oxidized carbon nanotube solution by a device.The oxidized carbon nanotubes will adhere to the tiny cilia of the elastic nonwoven fabric due to the van der Waals force.After drying,it will form a wearable flexible mechanical sensor based on the elastic nonwoven fabric.The characterization results show that the wearable flexible mechanical sensor based on non-woven fabric has good linear response characteristics in the range of 0³ kPa:when the forward pressure is 0⁰.4 kPa,the maximum resistance change rate of the sensor is-0.22 kPa^-1 and the resistance change rate of the sensor at 0.4 kPa to 0.6 kPa is-0.037 kPa^-1.