Hierarchical laser-programmed soft actuators for designing bionic robots with freeform morphing shapes.

Abstract

Bio-inspired shape-morphing structures, essential for next-generation soft robotics with unprecedented adaptability, demand actuators capable of complex and configurable three-dimensional motions. By overcoming traditional stimulus-responsive strategies facing the trade-off between manufacturing simplicity and kinematic sophistication, here, we introduce a spatially differentiated laser-programming technology for digital manufacturing laser-induced graphene-based soft actuators (LIG-SAs) with freeform morphing capabilities. Via cross-scale control of lasing energy and scribing direction, material heterogeneity and structural hierarchy can be tuned simultaneously for introducing decoupled electrothermal distribution and stiffness anisotropy, thus encoding LIG-SAs with four typical motion units: straight bending, directional curling, rigid supporting, and soft connecting. By arbitrarily grouping multimodal morphing units into concretized devices, this approach further empowers freeform design of bionic robots including octopus-like tentacles and inchworm/seal-like crawlers toward multitask locomotion of conformal grasping, path navigation, and obstacle avoidance. This framework bridges digital design with physical intelligence, unlocking previously unidentified avenues of soft robots for creating sophisticated and programmable morphologies.