Thin-Film Programmable Robotic Damper Enabled by a Stick-Slip-Free Electrostatic Clutch
Jihyeong Ma, Jongseok Nam, Nak Hyeong Lee, Ki-Uk Kyung
AI summary
Problem
Conventional electrostatic clutches suffer from stick-slip instability, restricting them to simple binary locking and preventing precise friction control needed for safe human-robot interaction.
Approach
The authors integrated a PVC-gel friction layer into an electrostatic clutch to eliminate stick-slip behavior, enabling stable sliding and real-time closed-loop control of kinetic friction under high shear stress.
Key results
- Achieves stable continuous sliding under 29 N/cm² shear stress at 100 V
- Enables high-fidelity closed-loop tracking of variable kinetic friction profiles
- Demonstrates active motion assistance for a robotic arm
- Validates programmable impact damping in a robotic leg and haptic rendering in a wearable glove
Why it matters
Provides a thin, low-power, and precise impedance modulation solution critical for next-generation wearable robotics, haptic interfaces, and safe human-robot collaboration.
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.