Mechanoresponsive self-growing hydrogels inspired by muscle training

TLDR

Polymer gels are generally too soft to self‑heal after deformation. The study seeks to create self‑healing polymers that restore mechanical strength after deformation. The authors generate double‑network hydrogels in which mechanical stress breaks the brittle network, generating radicals that polymerize new material to reinforce the gel. Repeated network breakage with monomer supply progressively strengthens the gel. Matsuda et al., Science, this issue p.

Abstract

Working harder, getting stronger Self-healing polymers attempt to restore mechanical strength after deformation. Polymer gels tend to be too soft for this to occur. Matsuda et al. generated self-healing hydrogels composed of a double-network material (see the Perspective by Craig). A mechanical stress breaks the more brittle of the two networks, while the other retains stability. On breakage, the fractured chains create radical initiators that polymerize new network material. With repeated network breakage and a supply of monomers, the gel gets stronger. Science , this issue p. 504 ; see also p. 451