Bioinspired tri-state optical gels with a thermally tunable modulus for 3D morphing

Shape-reconfigurable optical materials are promising for camouflage, sensing, and anti-counterfeiting, yet most existing systems produce only a single optical output and suffer from optical instability during deformation. Herein, a bioinspired tri-state optical gel (TOG) is fabricated by photopolymerization, incorporating SiO₂ photonic nanoparticles, SrAl₂O₄:Eu²⁺,Dy³⁺ phosphors and phase-change polymers. Phase-change components enable the gel to fix its geometry at low temperatures and to undergo programmable 2D-to-3D reshaping upon heating. Notably, the thermally tunable gel displays three distinct optical states under different illumination conditions: structural color under natural light, UV-triggered fluorescence and persistent phosphorescence. This work integrates programmable shape morphing and triple optical signals in a single gel, offering a facile route toward advanced dynamic optical composites.