Evaluation of two types of capacitive tactile sensors with different materials

Purpose To ensure effective and safe gripping, it is crucial to adjust the gripping force of a robot through the perception of tactile data during the gripping process. The purpose of this study is to evaluate the performance of two types of capacitive tactile sensors with different structures, designed for mounting on robotic grippers. Design/methodology/approach An experiment was conducted to measure the self-capacitance response to normal force when the sensors encountered different materials, including metal, cotton, plastic, aluminium, rubber and clay. The change in capacitance against the normal force applied was analysed to determine the sensitivity of each sensor for different materials and various force ranges. Findings Experimental results show that the sensitivity of the two types of sensors varies significantly across different materials and measurement ranges, with values ranging from 8.97%/N to 108.31%/N. The sensors exhibit different responses to materials with varying hardness, which is critical for robotic grippers to adapt their interaction strategies based on material properties. Originality/value This paper highlights the varying sensitivity of capacitive tactile sensors to different materials and force ranges. The findings contribute to the development of adaptive gripping strategies for robotic grippers, enhancing their ability to handle diverse objects effectively.