Multifunctional CFRP interfacial engineering via 355 nm laser-induced LIPSS

Nanoscale periodic textures can endow engineering materials with advanced functionalities, but conventional nanopatterning remains slow and costly. Here, a rapid, single-step method for fabricating highly uniform textures is presented; centimeter-scale laser-induced periodic surface structures (LIPSS, period ≈100 nm) on carbon-fiber-reinforced polymers (CFRPs) using a 355 nm, 10 ps laser. The LIPSS period is dictated solely by laser polarization, independent of scan trajectory or thermal effects, demonstrating deterministic optical control. Electromagnetic simulations and experiments reveal that surface plasmon polariton (SPP) excitation at the fiber/air interface governs ripple formation, with simulated and measured periods in excellent agreement (106 nm vs 112 nm), confirming a photonic-plasmonic mechanism. The resulting nanostructures impart: (i) superhydrophilicity (contact angle ≤5°) and a threefold increase in roughness within the LIPSS region compared to the original surface, both facilitating stronger interfacial bonding and coating adhesion; (ii) a sevenfold increase in surface potential and a reduction in surface resistance from 120.7 GΩ/sq to 8.6 kΩ/sq, features essential for electronic and energy device applications; and (iii) accelerated carrier relaxation dynamics, critical for fast optoelectronic and sensing performance. This work advances the understanding of LIPSS physics in composites and offers a scalable platform for multifunctional photonic interface engineering.