All-laser route for anti-fouling superhydrophobic albronze fabrication and non-contact microbial detection

Abstract

Biofouling leading to clog is one of the severe issues underwater valve components are facing today. Establishing a superhydrophobic barrier against microorganisms for underwater albronze components is hence of great significance. We demonstrate an all-laser route for superhydrophobic albronze surface fabrication and non-contact microbial diagnostics. Laser-textured albronze surfaces with well-defined periodic valleys and crests exhibit excellent superhydrophobicity with a contact angle up to 151 ± 1° and a contact angle hysteresis of 0.9 ± 0.1°, more than twice that of an original albronze surface (66 ± 2°). The theoretical wettability diagram of water droplets on laser-textured albronze surfaces shows that the surface wettability transits from hydrophilicity towards hydrophobicity as the surface undulation level elevated, matching well with the experimental observation. According to surface chemistry analysis, carbonyl groups on the albronze surfaces are extensively eliminated by laser texturing and vacuum heating treatment, which contributes to the wettability transformation. The anti-fouling performance of the laser-textured albronze surfaces was comparatively studied in chalk ash aqueous solution, starch solution, and microbial suspension, respectively. Laser-induced breakdown spectroscopy was applied for non-contact microbial diagnostics. Greatly enhanced resistance to biofouling on laser-textured albronze surfaces was confirmed. An all-laser route for anti-fouling superhydrophobic albronze surface fabrication and non-contact microbial diagnostics show great promise for next-generation underwater equipment upgrade and on-site monitoring.