A leaf-inspired robot combining embroidered structure with ion-induced actuation

Wearable soft robots engage fabrication strategies more resembling sewing than milling. For highest compatibility with the existing wearables - i.e., clothing, methods for embodying intelligence into textiles are sought. Combinatoric assembly on the existing textile platform suffers from bulkiness; thus, we present a method for integrating soft actuators as an inherent part of the textile. Specifically, machine embroidery was engaged in designing an actuator structure, where a single, continuous thread defined the individual actuators. A synthetic leaf was created with the embroidered supporting structure as the analogue to leaf veins and a pattern inspired by plant stomata. Electrolyte displacement bent individual actuators out of the plane, mimicking the opening of stomata via osmosis upon applying an electric charge to the spray-deposited electrodes. The thread-supported actuators yielded up to 8.4º reversible bending angle out of the plane. The integration of ionic actuators as an inherent part of a textile promises new compliant and safely activated actuation strategies directly compatible with the existing wearables' technologies.