Solvent-triggered reconfiguration of optical physical unclonable functions.

Abstract

Optical physical unclonable functions provide artificial fingerprints through randomized light-matter interactions, but are limited by static architectures that lack adaptive defense capabilities. Although reconfigurable optical physical unclonable functions based on phase-change materials have been proposed to overcome this constraint, their reliance on light or heat makes them susceptible to unintended environmental activation. Here, we propose a solvent-triggered reconfiguration strategy for optical physical unclonable functions based on polymeric microcube arrays confined within square microwells while retaining translational and rotational degrees of freedom. A volatile solvent induces swelling that establishes wall-cube contact; evaporation-driven detachment drives non-deterministic rearrangement into new spatial configurations, regenerating the optical fingerprint. A machine-learning-based authentication framework provides robust identification of encoded physical configurations. The resulting system exhibits remarkable stability under various environmental and mechanical stresses, while exposure to volatile solvents serves as an effective trigger for reconfiguration, offering a robust pathway to decouple the intrinsic trade-off between environmental stability and reconfigurability.