Fabrication And Research Of Multifunctional Flexible Sensor Array Based On Piezoelectric Film

Human skin is an important part of the human tactile system.It is mainly used as a sensor to convert various external stimuli into electrical signals,and then the electrical signals are transmitted to the brain through nerve fibers.However,for those who lose limbs,smart prosthetic integrated sensors can help the disabled restore the human tactile system,which is an important way to improve their quality of life.However,most sensors can only detect a specific stimulus,which is difficult to satisfy the demands.The real-time detection and differentiation of various external stimuli by the tactile sensor is still a huge challenge and limits the development of electronic skin.This thesis designs and fabricates a piezoelectric tactile sensor array inspired by human skin with a multilayer structure and horizontal and vertical electrode wiring patterns.Software simulation is used to analyze the stress distribution when the sensor is under different external stimuli,and optimize the parameters.High-precision patterned electrodes were prepared by magnetron sputtering and screen printing.A special test platform and system were built to test the performance of the sensor array.The sensor array was tested for pressure,bending,and multi-touch.To realize the differentiation of different external stimuli by the sensor,the logic algorithms are designed for signal processing of the sensor array.Experiment results show that the sensor array has high sensitivity(7.7mV/kPa),long-term durability(80,000 cycles test)and fast response time(10ms,less than the response time of human skin)under the pressure test.In the bending test,the sensor can not only detect the radius of the bend,but also the direction of the bend.In the multi-point test,the unique structure design overcomes the crosstalk problem.After signal processing,real-time detection and differentiation of the magnitude,position and pattern of various external stimuli can be realized,including slight sliding,touching and bending.The sensor has been successfully applied to real-time monitoring of human neck pulse,detection of small animal movements,working as a force feedback control of robotic hands and detection of temperature changes.These applications show that the tactile sensor proposed in this article has great potential in medical,industrial and other fields.