Research On Wearable Hybrid Sensor Array Based On Silk Fibroin

With the rapid development of science and technology,flexible wearable electronic devices have attracted extensive attention.Wearable electronic devices have attracted much attention because of their flexibility,wearability and multi-function integration.They have a wide application prospect in the fields of human health monitoring,bionic robot,biomedicine,artificial limb and so on.In recent years,the concept of electronic skin based on wearable devices has been put forward,which puts forward higher requirements for wearable electronic devices.Various components of electronic skin:sensors,actuators,communication,signal processing,energy collection and storage need to be paid more attention by researchers.As a key part of wearable electronic devices,the preparation process based on traditional integrated circuits has been mature and applied to the preparation of sensors.However,its high cost and strict material requirements often limit its application in flexible wearable sensors.At present,a variety of flexible sensor preparation processes,such as screen printing,mask spraying and electrospinning,have the characteristics of relatively simple preparation process and large-scale preparation,which broaden the preparation and application of flexible wearable sensors.At the same time,more and more new sensing materials have been found and applied.When further expanding the application of its sensing function,the biocompatibility and environmental friendliness of wearable devices are also very important.The current micro nano manufacturing process is relatively mature for the manufacturing of flexible wearable sensors with single sensing function,but the sensors with single function can not meet the various needs of electronic skin at the same time.Therefore,multifunctional wearable sensors based on new materials have been paid more and more attention.In this thesis,a flexible wearable hybrid sensor array based on silk fibroin is prepared,which has three sensing functions: temperature sensing,humidity sensing and tension sensing.The hybrid sensor array is based on silk fibroin,a new material with excellent biocompatibility.Taking the silk fibroin film prepared by calcium chloride formic acid system as the substrate,the mixed functional materials of silk fibroin and graphene are prepared on the substrate by screen printing process,and the silver conductive electrode is prepared on the substrate by mask spraying process.Based on different sensing modes,the sensor can perceive different external environments.The tensile sensor can detect the tensile ratio of the device in the range of 100%-178%,and the response speed is only0.5s;The detection range of the temperature sensor is 25 ?-48 ?,the sensitivity of the device is about 8% / ? in the temperature range of 25-35 ?,the sensitivity of the device is about 1% / ? in the range of 35-48 ?,and the maximum resistance change rate of the device can reach 98%;Humidity sensor can detect the ambient humidity in the range of 60%-85% relative humidity,and has good linear fitting.When the relative humidity changes by 1%,the change rate of the resistance value of the device is about3.02%.The hybrid wearable sensor can be used for human-computer interaction,and can realize the perception and detection of human touch,breathing,joint bending,etc.It has a good application prospect in the field of flexible wearable devices.