Thin-Film Programmable Robotic Damper Enabled by a Stick-Slip-Free Electrostatic Clutch

Abstract

Electrostatic (ES) clutches are promising candidates for wearable and assistive robotics due to their thin, lightweight, and low-power characteristics. However, conventional ES clutches typically suffer from mechanical instability caused by the stick-slip phenomenon, restricting their operation to simple binary (locked or free) modes. In this work, we present a Stick-slip-free Variable Electrostatic (SV-ES) clutch that functions as a high-performance programmable robotic damper. By utilizing a PVC-gel friction layer, the device achieves stable and continuous sliding even under high shear stress (29 N/cm² at 100 V). We demonstrate that this stability allows for precise closed-loop modulation of kinetic friction and motor-free position control. The versatility of the SV-ES clutch is validated through three robotic applications: active motion assistance for a robotic arm, high-fidelity haptic rendering, and programmable impact damping for a robotic leg.