The effects of electroadhesive clutch design parameters on performance characteristics

Actuators that employ clutches can exhibit mechanical impedance tuning and improved energy efficiency. However, these integrated designs have been difficult to achieve in practice because traditional clutches are typically heavy and consume substantial power. In this article, we describe a lightweight and low-power clutch that operates with electrostatic adhesion and achieves order-of-magnitude improvements in performance compared to traditional clutches. In order to inform appropriate design in a variety of applications, we experimentally determine the effect of clutch length, width, dielectric thickness, voltage, and electrode stiffness on the holding force, engage and release times, and power consumption. The highest performance clutch held 190 N, weighed 15 g, and consumed 3.2 mW of power. The best samples released and engaged within 20 ms, as fast as conventional clutches. We also conducted a fatigue test that showed reliable performance for over 3 million cycles. We expect electroadhesive clutches like these will enable actuator designs that achieve dexterous, dynamic movement of lightweight robotic systems.