Metabolism-Driven Morphomechanical Transitions in a Steady-Dynamic Covalent Double Network Living Hydrogel

Engineered living materials couple living biochemical activity with synthetic chemical networks yet translating biological processes into reversible structural and mechanical remodeling remains challenging. Here, we report a metabolism-regulated dynamic covalent double network living hydrogel that converts microbial D-glucose consumption into programmable network reconstruction and morphomechanical transitions. The living hydrogel combines a permanent covalent network that maintains structural integrity and microbial confinement, and a phenylboronic acid-poly (vinyl alcohol) dynamic network whose boronate ester equilibrium is regulated by D-glucose. Exogenous D-glucose competitively disrupts dynamic crosslinking, whereas microbial metabolism depletes D-glucose and promotes reconstruction of the dynamic network. This glucose addition-metabolism cycle enables reversible interfacial structural reconfiguration of living hydrogel modules, enhances bulk shrinkage, and converts chemical remodeling into bilayer bending actuation. The hydrogel supports diverse microorganisms, retains spatially confined populations, and undergoes repeated cycles of network reconstruction and mechanical actuation. By integrating actuation and genetically encoded sensing modules, we further construct a potentially recyclable living hydrogel device capable of sequential grasping and IPTG-induced bacterial sensing. This work establishes metabolism-regulated dynamic network reconstruction as a chemical strategy for coupling living biochemical processes with reversible morphology and mechanics in engineered living materials.