Contact sensing in a bio-inspired whisker driven by electroactive polymer artificial muscles

This work investigates the vibrissal sense of touch through actuation and contact detection in a bio-inspired whisker sensor. Actuation is provided by dielectric elastomer (DE) actuators, the capacitance of which is used as the sensing parameter. This paper presents a preliminary characterization of a simple rat-like whisker. The simplified structure is constituted by a single DE actuator, which acts both as a base support structure and actuator for the whisker (a rigid plastic rod). The capacitance of the DE is directly related to the whisker movements. When the whisker hits an object the base of the whisker is constrained, and planar expansion of the DE is modulated. This restriction is simultaneously measured through capacitance changes. This measurement may also be used to measure whisker contact even when the whisker is still. The results presented show the effectiveness of the self-sensing whisker in tasks of object detection and relative movement measurement.