Self‐Sustained Robots Based on Functionally Graded Elastomeric Actuators Carrying up to 22 Times Their Body Weight

Abstract

A biomimetic strategy of combining soft actuators with an exoskeleton is applied to create untethered, self‐sustained robots with high load capacity, applicable for transportation in unsupervised environments. The soft actuation components are based on liquid crystal elastomers formed into functionally graded structures by extrusion printing, which enables a high free strain of 45.5%. The robot design includes a self‐sustained oscillation mechanism incorporating a novel, highly elastic spring for energy storage and impulse release. The arthropod‐inspired exoskeleton structures are printed from polycarbonate with high strength to increase the load‐carrying capacity, or to increase moving speed by a lever mechanism that amplifies the stepping distance up to eight times. The robot achieves self‐sustained locomotion, harvesting constant infrared radiation for continual power. Leveraging the strength of the exoskeleton and the high stress of the actuator, the robot transports a load 22 times its body weight. It is capable of climbing up a slope of 40° and moving up to a quarter of its body length per minute with peripheral lever legs. The robot operation does not require external signaling controls or complex electronics, demonstrating the potential of this battery‐free, scalable, environment‐powered design with an unlimited range free from tethering constraints.

Keywords

• functionally graded structures
• liquid crystal elastomers
• 3D printing
• self-sustained robots