Piezochromic hydrogels for physically unclonable optical anti-counterfeiting with machine-learning assisted automatic identification

Developing high-security anticounterfeiting with reliable authentication remains a significant challenge in preventing information leakage and economic losses from counterfeiting. Here, we successfully reported physically uncopiable optical system based on piezochromic polymer hydrogels (PPH). Pressure treatment induces a clustering-triggered emission transition from red to blue, driven by suppressed through-space interactions and reduced electron delocalization, with the blue-emissive state sta