Contour-Regulated Microfabrication of Metallic Honeycomb-like Structures via Ultrafast-Laser-Ablation-Designated Chemical Etching

The hybrid of ultrafast laser ablation and chemical treatment for achieving high-precision modulation of surface micro/nano structural contours has been a research focus in the micro/nanofabrication field and facilitated various applications. However, current hybrid approaches primarily target dielectric or nonmetallic materials, and the precise control over both micro/nano structural qualities and contours on metal surfaces remains an unresolved challenge. Herein, we report a contour-regulated microfabrication method via ultrafast-laser-ablation-designated chemical etching for controlled preparation of various micro/nanostructures on metal surfaces. Specifically, two-way effects are realized, i.e., the ultrafast laser-made micro/nanostructures can guide the wet-chemical etching, and the wet-chemical etching can modulate the ultrafast laser-made micro/nanostructures, via the modified chemical reactivities at different structure locations. The contour-regulated microfabrication method enables the reshaping of micropatterns on metal surfaces from irregular elliptical microunits to circular and even hexagonal ones in a controlled manner, with both the structure qualities improved and structure contours modulated within one process. The contour-regulated microfabrication method has flexible adaptivity for treating various patterns and structures fabricated by ultrafast laser, even for parallel reshaping of ultrafast laser-made precursor structures with varying layouts. As a demonstration of surface function control, closely packed honeycomb-like structures with uniform geometries are produced, exhibiting excellent superhydrophobic and icephobic performances, with steady low ice-adhesion strength <10 kPa during 10 icing/deicing cycles. This study can broaden the technical scope of etching-assisted ultrafast laser microfabrication and hold promising potential for various practical fields requiring controlled micro/nanoscale surface patterning.