Programmable soft materials enable smarter, direction-based robotics

Researchers at The Hong Kong University of Science and Technology (HKUST) have developed a novel class of soft, programmable composite materials that exhibit highly tunable, asymmetric mechanical responses depending on the direction of applied force. By integrating shear-jamming transitions into compliant polymeric solids, these materials can stiffen dramatically under shear stress while remaining flexible otherwise. This innovation enables soft structures to behave differently when pushed, pulled, or twisted from various directions, overcoming limitations of traditional metamaterials that often rely on rigid, fracture-prone frameworks. The resulting composites are programmable, defect-tolerant, and fracture-resistant, with mechanical properties that can be tailored across multiple scales. The HKUST team demonstrated that these materials, when combined with spatially modulated magnetic profiles, can form “active soft solids” capable of directional motion, mimicking bio-inspired robots that navigate confined environments inaccessible to conventional robots. Applications extend to selective flow-control valves in microfluidic systems, soft pumps, biomedical devices, and adaptive medical tools. This