Asymmetric Flexible Electroadhesive Clutches

SummaryFlexible electroadhesive clutches with high shear stress working at low voltage and fast response are much desired in wearable electronics and robotic systems. Dielectric materials of opposite electron affinity may enhance the clutch performance by boosting the electrostatic attraction between the two surfaces in an asymmetric clutch. In this paper, the first batch of asymmetric electroadhesive clutches is proposed, fabricated and evaluated. The effect of the charge characteristics of the dielectric materials on the clutch performance is investigated. A shear stress of 197.30 ± 15.44 kPa is generated at 300 V in around 20 ms by the asymmetric clutch made from polyurethane and polyimide active dielectric pads. The shear stress is more than eight times of other reported symmetrical clutches working at a similar voltage range. In addition, the hydrogen bonds at the interface are found to contribute to the high electroadhesive stress. This work demonstrates an effective asymmetric and multi-mechanism strategy to develop high performance electroadhesive clutches with diverse materials selection.