Acoustic Soft Tactile Skin: Towards Continuous Tactile Sensing

Abstract

Acoustic Soft Tactile (AST) skin is a novel sensing technology that uses deformations of the acoustic channels beneath the sensing surface to predict static normal forces and their contact locations. AST skin functions by sensing the changes in the modulation of the acoustic waves traveling through the channels as they deform due to the forces acting on the skin surface. Our previous study tested different AST skin designs for three discrete sensing points and selected two designs that better predicted the forces and contact locations. This paper presents a study of the sensing capability of these two AST skin designs with continuous sensing points with a spatial resolution of 6 mm. Our findings indicate that the AST skin with a dual-channel geometry outperformed the single-channel type during calibration. The dual-channel design predicted more than 90% of the forces within $\mathrm{a}\pm 3\mathrm{N}$ tolerance and was 84.2 % accurate in predicting contact locations with $\pm 6$ mm resolution. In addition, the dual-channel AST skin demonstrated superior performance in a realtime pushing experiment over an off-the-shelf soft tactile sensor. These results demonstrate the potential of using AST skin technology for realtime force sensing in various applications, such as human-robot interaction and medical diagnosis.