Capacitive Touch-slip Sensor Based On Dielectric Layer Of Polyimide Nanofiber Membrane

The intelligent development of robots and unmanned combat equipment,which must be conformally attached to the surface of the structure to sense contact force and shear force,puts higher demands on tactile sensors.Aiming at the problems of low sensitivity,single detection direction and complex structure design of tactile sensors at home and abroad,this paper proposes a capacitive flexible three-dimensional tactile sensor with nanofiber membrane as dielectric layer.Research work is carried out on the design and manufacture of capacitive flexible touch sensors,the comparison of sensor performance of different materials and structural dielectric layers,the design of sensor arrays and the construction of sensor test systems.The main progress is as follows:The cell structure of the capacitive flexible touch-slip sensor is designed.And the capacitive touch-slip sensor based on the single-layer PI fiber membrane dielectric layer was simulated by Comosol Mutiphysics,and the PI fiber membrane structure was proved to have excellent three-dimensional force sensing performance.The performance of the PI nanofiber film and the structure size sensor of different dielectric layers,layer thicknesses and layers is compared and analyzed.The test results show that he small size capacitive touch-slip sensor which based on the dielectric layer of the double-layer PI nanofibers membrane performs optimally.Under the pressure of 0-13.89 kPa,the average sensitivity in the z-axis direction is up to 0.0480 kPa-1;in the interval of 0-0.18 N,the average sensitivity in the x-axis direction is 0.6216 N-1;at 0-0.26 N,the y-axis The average direction sensitivity is 0.7684 N-1,the response time and recovery time are 87.5 ms and 192.5 ms,respectively,and exhibits good stability and repeatability.Through the structural design,a capacitive touch-sensing array is finally produced,which has a maxim?m sensitivity of 2.204 kPa-1 in the range of 4.1-4.9 Pa in terms of tactile perception,and an average sensitivity in the x-axis direction in terms of sliding perception for 0.1218 N'1,the average sensitivity in the y-axis direction is 0.0912 N'1,the response time of the sensing array is 157.5 ms,and the recovery time is 175 ms,which also has good repeatability.In order to study the contact force detection performance of the tactile sensing array,a scanning circuit of the capacitive flexible tactile sensing array was developed,and a real-time display system for the position and size of the contact force was constructed.The sensing array was tested by the scanning test system.The results show that the flexible touch-slip sensor developed in this paper can be used for contact and sliding detection of robot skin.