Selective laser-induced etched molds for forming textured polymers

Selective Laser-Induced Etching (SLE) is a micromachining technique specifically applied to transparent materials like various glasses, involving laser irradiation to locally modify the material followed by wet chemical etching for selective material removal. We adapt the SLE method to optimize femtosecond laser patterning of fused silica molds for casting polymer-based high aspect ratio microcavities with enhanced light absorption properties. Surface reflow via CO2 laser polishing addresses issues of surface roughness and polymer adhesion, impacting surface smoothness and reflectance. Our findings demonstrate SLE's potential for efficient fabrication of intricate microstructures for applications of flexible, dark surfaces.