Design of a soft 3-axis load cell for human-robot interactions

This paper describes a soft three-axis tactile sensor composed of a soft-rigid multi-material structure embedded with microfluidic pressure sensitive channels. The sensor contains two types of microchannels filled with a liquid conductor for different sensing purposes: one for detecting normal forces and the other for detecting shear forces. While normal forces are measured by a single microchannel, shear forces are detected by a microchannel divided into six segments for an increased spatial resolution. The proposed sensor provides a total of seven output signals based on the direction of the applied force, making it possible to decouple force elements in x, y and z axes.