Dynamic Supercooled Crystal–Gels for Ultrafast, Reversible Mechanical Adaptative Materials

Endowing synthetic materials with adaptability and responsiveness to dynamically optimize their states represents a premier frontier in biomimetic science. However, achieving life-like, rapid yet reversible adaptation under benign triggers remains hindered by high reconfiguration energy or delayed structural recovery. In this work, we present dynamic supercooled crystal-gels that achieve ultrafast, reversible stiffening without requiring continuous energy input. Inspired by the tactile-triggered stiffening of starfish tissues, it utilizes non-equilibrium energy of internal supercooled liquid to realize templated crystallization upon a benign tactile stimulus trigger. Meanwhile, the crystalline structure is reversible under appropriate temperature and humidity perturbations. This synchronously achieves a 2596-fold adjustment in compressive modulus, circumventing the conventional trade-off between energy demands for mechanical reinforcement and structural stability. As a functional validation, microneedles based on supercooled crystal-gels fulfill the divergent requirements for skin adaptation and seconds-scale drug release through their mechanical adaptation, achieving rapid cumulative drug release of ≈37.76% at 10 s and 88.12% within 5 min. This work delineates a strategy for endowing materials with autonomous mechanical adaptation and opens new opportunities for life-like functional evolution in soft robotics and bio-integrated electronics.