Research Of Carbon Nanotubes Doping Polymer-Besed Flexible Mems Tactile Sensor

In recent years,with the rapid development of flexible electronics,wireless communications,MEMS and other technologies,flexible wearable devices have attracted more and more attention.As the core of flexible wearable devices,flexible sensors have become the focus in this field.With the trend of the contact force of objects minimizing and the requirement of high accuracy for environment,the array sensor based on MEMS technology is developing towards integration and miniaturization.At the same time,with the diversification of the application scene,the sensing precision of strain,pressure and temperature is also improving.By attaching flexible / wearable devices on the human body,combined with the characteristics of high sensitivity and high flexibility,these sensor arrays have the tremendous potential in advanced robotics,new generation of prosthetics and medical monitoring.This paper mainly studies the flexible MEMS tactile sensor based on polymer doping carbon nanotubes,main works including:(1)Sensing mechanism of tactile sensor and selection of sensing materials were researched,the doping of carbon nanotube and liquid crystal,and the doping of carbon nanotubes and hydrogels were also researched.Firstly,we understood the characteristics of hydrogel in the way of preparing hydrogel.The mechanical and electrical properties of the device were also investigated by doping multi-walled carbon nanotubes with different mass ratios.Finally the methods of preparation and the ratio were confirmed.Secondly,by studying the anisotropy of liquid crystal molecules at different voltage and frequency and the compatibility with multi-walled carbon nanotubes,liquid crystal doping with multi-walled carbon nanotubes(LC-CNT for short)was identified to be another sensor sensing layer.(2)By studying the doping of hydrogels and multi-walled carbon nanotubes,a flexible tactile sensor with hydrogel doped multi-walled carbon nanotubes was designed and fabricated.The device was designed and used to measure and collect human pulse waves with the help of the signal processing circuit.(3)The doping of liquid crystal and multi-walled carbon nanotubes was used as the sensing layer,hydrogel was used as protecting layer and a 4 × 4 flexible sensor array was fabricated.The changes in the capacitance of the device were observed with different voltage of the voltage source and the output frequency.At the same time,by the linear fitting,we found that the device has different testing accuracy under different frequencies and voltages,and adjustable testing range pressure sensor was accomplished with this character.