A switchable flexible mechanical clutch based on self-amplified friction of interleaved layers

Clutch mechanisms that are lightweight and have low power consumption are crucial to enhancing the functionality of many robotic systems. We present the design, characterization, and modeling of a switchable clutch based on the self-amplified friction between thin flexible sheets. The clutch consists of interleaved paper sheets, which maintaining a locked state akin to that of interleaved books. Unlocking is achieved by applying rotation to the distal ends of the interleaved assembly, counteracting the self-amplified normal force within the layers. A 60-layer paper-based interleaved clutch, weighing 9 g, exhibits a locking force capacity of ∼550 N, along with an unlocked state force of ∼1 N. Through the incorporation of rubber bands, the clutch achieves bistable switching and self-resetting capabilities. In addition, we demonstrate an application of the clutch by integrating it into a wearable posture corrector.