A Flexible Touch-Sensing Sensor Based on the Theory of Non-Uniform Gradient Potential Distribution

Tactile perception is very important for the physical interaction between robots and the external environments. Based on the theory of non-uniform gradient potential distribution (GPD), a novel non-array flexible touch-sensing sensor is proposed in this paper. It can detect whether there is a touch, and further to know where the touch took place. The sensor uses an indium-tin oxide polyethylene terephthalate (ITO-PET) film as signal generation layer. The electric fields in two different directions are constructed by time-sharing in the ITO-PET conductive plane, and the potential distribution over the ITO-PET film has the characteristics of uniqueness and determinacy. The touching position can be worked out by detecting the potentials of the touching point in two directions, respectively. In order to establish the relation between the position and the potential value effectively, quickly and accurately, the radical basis function (RBF) neural network is used to construct the electric field model and calculate the touching position coordinate. A detection circuit was designed to detect the touching position of the sensor sample. The simulation and experimental results show that the detection principle proposed in this paper is feasible, and the real-time detection of single point touching position can be realized. The touch-sensing sensor is simple in structure, thin in thickness and soft in flexibility. It can cover the surface of the robot and obtain external touching information in real time.