A Study Of A Flexible Contact Sensor

In recent years,with the development of robotic intelligent technology,more and more attention has been paid to the research on the associated technologies.The accurate and fast perception of the external environment is the basis of intelligence,and the tactile sensor is the realization of this function Therefore,the research and application of contact sensors have very important significance.In practical application,the flexible contact sensor needs to have two characteristics.First,the robot's perception of the outside often requires the contact sensor to detect the multi-dimensional force in space,including the normal force and the tangential force.Second,the contact sensor needs to have similar human skin flexibility and ductility,which can be covered in the irregular contact surface,so as to better realize the perception of the external environment and operations.Therefore,the development of a flexible contact sensor capable of multi-directional force detection and having similar human skin mechanical properties is one of the important conditions for the robot to realize intelligence and has broad application prospects.However,the current flexible contact sensors are mostly made of rigid materials or non-flexible material,lack of flexibility,and most of them can only detect the tangential force or normal force in one direction.Based on the reports in literatures,we developed a capacitance style flexible contact sensor.The sensor consists of four capacitors and its body and the electrodes are made of flexible material,which can detect both the normal and tangential forces.Each capacitor in the sensor is more sensitive to the force along the specific direction.In addition,the flexible sensor has the simple process,simple structure and high reliability,and it provides a new idea for the design and manufacture of the flexible touch sensor in the future.The main work of this paper includes the following sections1)Based on the principle of capacitance style sensor,a structure design scheme of flexible contact sensor was proposed to realize the measurement of normal force and tangential force.The sensor uses hyperelastic flexible electrodes which offer greater sensitivity and flexibility than conventional metal electrodes.The sensor uses a fourcapacitor structure with two layers so as to have different sensitivities to the three directions of the force.The external force is detected by combining the four capacitance values.The working principle of the flexible tactile sensor is described.The material of the sensor is selected,and the manufacturing process of the sensor is introduced.2)The COMSOL Multiphysics software was used to simulate the sensor electromechanical coupling,which verified the sensor working principle and provided some references for the development of the sensor.3)In order to verify the performance of the sensor,the output characteristics of the flexible sensor were tested through a series of experiments,including the output characteristics of three axial forces.4)In order to compare the advantages of flexible electrodes and metal electrodes,a flexible sensor with the same size of metal electrodes was fabricated.The sensitivity and flexibility of sensors of flexible electrodes and metal electrodes were compared and tested.