Reconfiguring handed shape-morphing and actuation in hydrogels via light-encoded rapid expansion

Reconfiguring handedness in synthetic systems with spatiotemporal control and reversible behavior remains a fundamental challenge in bioinspired robotics and materials science-especially in structurally homogeneous materials that lack intrinsic chirality. Here, we demonstrate homogeneous photoactive hydrogels capable of ultrafast, programmable handed shape-morphing, including helices and twists, through spatially controlled light illumination. This transformation is driven by a photoexpansion exceeding 80,000% volumetric growth within 40 seconds, enabled by the synergistic combination of spiropyran photoisomerization and tailored polymer-network interactions. Deterministic strain mismatches at illuminated interfaces allow on-demand forming and shaping of handed architectures, which can be erased in darkness and reprogrammed reversibly with light. We further synchronize opposing handedness and complex tendril-like geometries in a single material, and exploit handedness to achieve self-propelled rotation for robotic locomotion. This work introduces a versatile method for adaptive, lifelike chirality in homogeneous matter, closing a key gap between biological shape-morphing and engineered soft robotics.