A versatile and modular capacitive tactile proximity sensor

In this work we discuss the design and realization of a novel capacitive tactile proximity sensor (CTPS) with applications in robotics and consumer-electronics. The current concept is an advancement with respect to a previous design developed at our lab. Experience in the development of applications based on the old sensor, such as manipulation and safe HRI, helped determining the requirements. The new sensor is capable of operating in a self- and mutual-capacitive proximity mode and in a mutual-capacitive tactile mode. The issue of having a trade-off between spatial resolution and sensing range in proximity mode due to the capacitive measurement principle is addressed. A circuit is designed to dynamically select or join electrodes involved in the proximity measurements, a technique which at the same time allows the implementation of the spatial resolution in the tactile mode. Also, all signal processing is done on board of the prototype sensor module, thus complete modularity is achieved.