Soft Tactile Sensors for Robot Grippers Using Acoustic Sensing

Abstract

We present a low-cost, soft tactile sensor using common, easily sourced materials that can be integrated with existing robotic gripper systems without requiring complex fabrication techniques or expensive components. Our approach includes two designs: a flexible linear sensor constructed from a rubber tube and a planar sensor made with a rubber membrane stretched over an enclosure. Both sensors contain an embedded speaker and microphones that leverage active acoustic sensing to map the unique acoustic resonant response of the cavity’s structure to deformations that occur when the robotic gripper is grasping an object. Experimental results demonstrate that, using a support vector machine, the linear sensor achieves contact point estimation with an RMSE of 6 mm, while the planar sensor achieves an RMSE of 0.57–0.62 mm. Additionally, the planar sensor classifies six objects with an accuracy of 97.7%. These results demonstrate the potential for active acoustics to be an accessible method for enabling tactile sensing capabilities for robotic systems.