Design And Realization Of Flexible Dual-Mode Sensing System For Tactile Perception

Flexible tactile sensors can convert external stimuli such as pressure,vibration,and temperature into manageable electrical signals.Due to the characteristics of high integration and excellent flexibility,flexible tactile sensors have huge application potential in medical monitoring,intelligent robots,and human-computer interaction.This thesis proposes a highly sensitive flexible tactile sensing system with dual-mode perception capability that can detect pressure and temperature simultaneously in response to the current problems of low integration and sensitivity in the research on flexible tactile sensors,and demonstrates its application prospects for wearable devices and electronic skin.The main research contents of the thesis are as follows,（1）A flexible pressure sensor with high sensitivity and wide working range is proposed based on the piezoresistive effect.The sensitive layer with high conductivity and stability is fabricated by combining inverted pyramid surface microstructures with double-covered sensing layers.The cloth is patterned by using the laser cutting technology to prepare the interdigital electrode with a large-scale processing potential.Besides,the preparation of the self-cleaning layer enhances survivability of the sensor under harsh environment.The sensor exhibits an ultrahigh sensitivity of 451.3 k Pa^-1,a wide sensing range of 250 k Pa,a fast response time of 29 ms,and excellent durability of 5000 cycles.（2）The graphene/carbon nanotubes conductive paste is used as sensitive material to prepare a flexible temperature sensor with excellent temperature sensitivity and high stability by using low cost screen printing technology.The testing results show that the sensor exhibits a sensitivity of 0.17%℃^-1 in a sensing range from-12.5℃to 93.7℃,and it is almost unaffected by bending deformation and humidity.（3）The integrated design of the dual-mode sensor is realized through structural optimization,and a signal acquisition system is built to collect,process and display dual-mode signals.The signal acquisition circuit consists of microprocessor,series voltage divider and Bluetooth transmission module,and the processed dual-mode signals are displayed in APP in real time.Real-time monitoring and display of temperature and applied pressure during object grasping can be achieved through the flexible tactile sensing system worn on a human hand or a manipulator.The flexible dual-mode tactile sensing system designed in this article can realize real-time detection of pressure and temperature,and has broad application prospects in electronic skin,intelligent robots,and wearable electronic devices.