Elastomers Combining Damping Efficiency With Rapid Recovery

ABSTRACT Damping materials are essential for protecting sensitive components and structures, for example, in wearable electronics, soft robotics, prosthetics, and personalized sports equipment. Elastomers are widely used as dampers because of their viscoelasticity. However, due to their viscoelasticity, the amount of energy they can dissipate must be traded off with the shape recovery speed. This trade‐off limits their ability to damp impacts that occur at moderate to high frequencies. We demonstrate that double network granular elastomers (DNGEs), composed of stiff microparticles connected with a soft network, can overcome this trade‐off. We leverage the 3D printability of these materials to produce complex structures with locally varying composition to maximize resistance to cyclic loading and impact. To increase the environmental friendliness of this durable material, we render it recyclable by introducing dynamic covalent bonds in the second network. We demonstrate that this material can be recycled under benign conditions without significantly affecting its mechanical properties. We foresee this material to enable the formulation of durable and recyclable dampers with tunable mechanical properties that are well‐suited dampers for certain sports equipment and wearables.