Research Of Stretchable Tactile Sensor Based On Capacitors Array

The scalable,bending,folding feature of flexible electronic devices can be perfect to satisfy the requirement of adapting to the real world of physical objects surface complex 3D structure and structural changes in real-time.For that,flexible electronic devices are being paid more and more attention by people,which have an extremely significant application prospect in consumer electronics,intelligent robot and bio-medical.This paper mainly studied capacitive flexible tactile sensor based on two kinds of structure:Parallel Plate Structure(PPS)and Circular Involute Structure(CIS),including structure design,process preparation and performance testing,finally explores the device equipped in mechanical arm for application test.Specific research contents and results are as follows:1.Design the flexible tactile sensor based on PPS and CIS capacitor array.Low modulus elasticity——polydimethylsiloxane(PDMS)are made of substrate and dielectric layer as well as copper consist of the electrode layers.The bending coiled lines connect the metal plates,to improve the flexibility and extensibility.Between the metal layer and PDMS layer,there is Polyimide(PI)base,which can enhance the mechanical device against the tensile strength to guarantee stability of the device and good electrical properties.In addition,the dielectric layer of PPS capacitor is formed by bar columnar array,which can improve the deformation of dielectric,further improving the sensitivity of sensor.2.Explore a set of mature processing technology of capacitor flexible tactile sensor,at the same time and test the sensitivity of sensor and its temperature stability.Laboratory conditions under clean room,the sensors are processed by micro-nano processing instrument.And its performance testing content mainly includes sensitivity and temperature stability.In 1 kHz-1MKz frequency,PPS capacitive sensors sensitivity is 4.10%/N.In 1 kHz-1MKz frequency,when the force is in the range of 0-3 N,the CIS capacitive sensors sensitivity is about 6.10%/N,while the force is more than 3N,its sensitivity will decrease constantly till above zero.In 1 MHz frequency,the PPS sensor does not change with temperature,but the temperature coefficient of sensitivity of CIS sensor is-1.07 Pf/N°C.3.Sensor is equipped with mechanical arm for an application test.Considered the size of mechanical fingers and based on PPS structure,a sensor is processed with a simplified process.And then we design and fabricate an integrated circuit for acquiring stable accurate data.Finally,we determine that the apple is true or fake by grabbing it with the mechanical arm.This experiment embodies the sensor the application prospect of bionic artificial skin touch system in the future.