Large-area fabrication of low- and high-spatial-frequency laser-induced periodic surface structures on carbon fibers

TL;DR

This study demonstrates the large-area fabrication of both low- and high-spatial-frequency laser-induced periodic surface structures on carbon fibers, including hybrid structures, using femtosecond laser pulses, with potential applications in composite materials.

Contribution

It introduces a method to produce homogeneous, large-area LIPSS on carbon fibers, including novel hybrid structures formed by superimposing different LIPSS types.

Findings

Successful fabrication of large-area LIPSS on carbon fibers.

First realization of hybrid LIPSS structures by superposition.

Potential for tailored surface structures in composite applications.

Abstract

The formation and properties of laser-induced periodic surface structures (LIPSS) were investigated on carbon fibers under irradiation of fs-laser pulses characterized by a pulse duration $\tau$ = 300 fs and a laser wavelength $\lambda$ = 1025 nm. The LIPSS were fabricated in an air environment at normal incidence with different values of the laser peak fluence and number of pulses per spot. The morphology of the generated structures was characterized by using scanning electron microscopy, atomic force microscopy and Fast-Fourier transform analyses. Moreover, the material structure and the surface chemistry of the carbon fibers before and after laser irradiation was analyzed by micro Raman spectroscopy and X-ray photoelectron spectroscopy. Large areas in the cm$^{2}$ range of carbon fiber arrangements were successfully processed with homogenously distributed high- and low-spatial frequency LIPSS. Beyond those distinct nanostructures, hybrid structures were realized for the very first time by a superposition of both types of LIPSS in a two-step process. The findings facilitate the fabrication of tailored LIPSS-based surface structures on carbon fibers that could be of particular interest for e.g. fiber reinforced polymers and concretes.