Mechanical Training-Induced Restructuring Enables Self-Extendability and Mechanical Consistency in Organohydrogels

Echinoderms, such as sea cucumber, dynamically change their body size to environmental stimuli. By contrast, typical synthetic materials cannot reinvent their structures once formed. We propose a strategy for developing "self-extendability" polymeric materials that can be structurally tuned by repetitive mechanical stress stimulation. Polyion complex glycerol (PICG) hydrogels undergo self-extendability and mechanical consistency, and the materials substantially grow in deformation under repetitive loading through a diffusion of disentangled dense structure to sparse structure. This strategy is generalizable to other polymers and topologies. Additionally, the gel is able to adhere to 3D surface. These advancements make our gels ideal for e-skin substrate materials; they simultaneously offer extended performance and curved surface attachment. This work may open an avenue for the development of self-extendability materials for intelligent devices.