Suture‐Inspired Interlocking Metamaterials for Energy‐Efficient Morphing

Abstract

Morphing metamaterials enable programmable shape changes for soft robotics and wearable systems, but intrinsic softness limits load‐bearing capacity and robustness. Architected particle assemblies connect discrete rigid particles with tendons, enabling compliance and active assembly into stiff, load‐bearing configurations. However, they require continuous energy input or external confinement to maintain morphed states, reducing efficiency and reliability. Here, we introduce a bistable interlocking joint inspired by natural sutures for architected particle‐based metamaterials that enable “move‐and‐hold” functionality. Once assembled, these joints allow structures to retain their configuration without sustained actuation while achieving load‐bearing capacity exceeding 60 times their own weight. To achieve this, we first develop computational algorithms to tessellate arbitrary 3D surfaces into particles with interlocking joints. Experiments and FEM simulations reveal how joint geometry influences interlocking strength, actuation force, and bending performance. Tendon‐driven assemblies demonstrate low‐force morphing, stable load‐bearing capacity without continuous energy input or external confinement, and adaptability to complex 3D geometries. As applications, we showcase a proof‐of‐concept foldable impact‐attenuation helmet that combines compact folded volume with impact attenuation under tested conditions, and further extend the concept to reconfigurable wearable devices, highlighting the potential of particle‐based architectures for protective and rehabilitation applications.