Modeling, Simulation and Experiment of Electric Potential and Contact Position Based on Flexible Array-less Capacitive Tactile Sensor

Abstract

As an important medium of human-computer interaction, flexible tactile sensors have a vital influence on the intelligence and safety of the system by accurately identifying the contact position. For now, most of the existing flexible capacitive pressure sensors adopt an array structure, which still cannot meet all the requirements including simple manufacturing, simple wiring, and low cost. This paper innovatively proposes a flexible array-less capacitive tactile sensor, which is a 30mm × 30mm sensor prototype. Under the action of the contact force, the contact area is deformed, the stability of the electric charges on the upper plate is destroyed, which leads to the redistribution of electric charges and the movement of electric charges generates current. The current will result in unequal distribution of the electric potentials in the upper plate area due to the characteristics of the resistance. Poisson’s equation is used to determine the relationship between the electric potential and position. Simulation and experimental results verified the effectiveness of the proposed mathematical model, showing that the recognition resolution of contact position can reach 500μm × 100μm. Most importantly, it does not rely on complex manufacturing, redundant circuits, or sensor cell arrays. Therefore, it has broad application prospects in related fields such as electronic skin and wearable electronic devices.