Tactile sensing is important for a robot to interact with the external environment. Currently, most robots can handle a known object at specific location, but they are vulnerable to an unknown object and/or unknown environment. Tactile sensors play an important role in interaction between a robot hand and an unknown object because tactile sensors can provide necessary information on touch detection and for feedback control. Among various tactile sensing techniques, capacitive sensors have gained popularity, due to their simple structure, high sensitivity, low power consumption, quick response, wide dynamic range and low cost. During my Lecture, I will start from the need of tactile sensors for robot applications, and review existing tactile sensing technologies. Then, I will introduce the principle and implementation of a type of capacitive tactile sensor, which can sense 3D force, and a dedicated design of a digital-analogue hybrid chip, which contains a capacitance-to-digital converter (CDC), a 32-channel multiplexer, an ARM microcontroller and a router, facilitating collaborative capacitance measurement across multiple chips. I will describe applications of the capacitive tactile sensors and the developed chip on robots with video demonstration, and also discuss other possible applications, including implementation of artificial skin, intelligent functions for cars, elderly care, and the possibility to develop a very low-cost electrical capacitance tomography (ECT) device.
