Luminescence meets physical unclonability in fracture engineered porous polymer skeletons for anticounterfeiting.

Counterfeiting remains a persistent global challenge, necessitating security technologies that combine robust unclonability with rapid, field-verifiable accessibility. Conventional optical labels with uniform designs are easily replicated, while most physical unclonable functions (PUFs) rely on complex fabrication processes or specialized readout systems, limiting their practical deployment, especially considering the broad accessibility of smartphone-based authentication. Here, we report a materials-driven strategy that unifies luminescence and physical unclonability through fracture-engineered polymer PUFs. Porous polymer skeletons bearing customized patterns are printed via maskless photolithography and subsequently functionalized by surface-initiated ATRP with Ir-based complexes and fluorescent dyes. This design yields Förster resonance energy transfer (FRET)-enabled, intensity-amplified, and spectrally multiplexed emissions under single-wavelength excitation, enabling optical information encryption and straightforward decoding. Crucially, the porous architecture supports fracture-engineered tape transfer that preserves macroscopic luminescent patterns while spontaneously generating stochastic microscale features at each pixel, producing intrinsically unclonable fingerprints. The resulting mechanically durable tags integrate bright, stable luminescence with reliable PUF characteristics and enable field-readable authentication using only a handheld flashlight and smartphone imaging, without the need for specialized instrumentation. By coupling luminescence with luminescence-enhanced intrinsic PUF security on easily readable tags, this work establishes a versatile and scalable platform for on-site customization and on-demand anti-counterfeiting authentication.