Design and Implementation of Robot Skin Using Highly Sensitive Sponge Sensor

Robot skin, as a key component to collect tactile information, plays an important role in human-robot interaction (HRI). Conventional robot skin is mainly made of rigid components and bendable films, which cannot provide a fully soft physical interface in HRI. In addition, the sensitivity of robot skin is still to be enhanced so that robot could perceive touch behavior more precisely from a human. Here, a novel robot skin with features of high sensitivity and softness is designed in this article. The proposed robot skin is composed of a matrix of carbon black-polyurethane sponge sensor units through a foaming process. The sensitivity of the sensor is further enhanced by optimizing its geometric structure, based on the finite element method and physical experimental tests. The excellent cycling stability and transient responsiveness of the sponge sensor embedded into the robot skin endow host robots with an accurate long-term perception of both transient and quasi-static force. Finally, the validation of the robot skin is carried out by installing it on the back of a collaborative robot to perceive four touch modalities, illustrating great application prospects in affective HRI.