Manufacturing of anti-fogging super-hydrophilic microstructures on glass by nanosecond laser

Abstract

In this paper, a nanosecond laser processing method with the support of light-absorption auxiliary materials was developed to fabricate anti-fogging super-hydrophilic microstructures on glass substrate surfaces. Through adjusting the focal point offset, the laser was focused on the auxiliary material layer, thus the laser energy required for micromachining was precisely controlled. As a processing example, a bionic honeycomb structure was successfully manufactured by this method. The effects of laser processing parameters on the size and integrity of the fabricated microstructures and on the light transmission of the machined surface were investigated through laser machining experiment. The results indicate that lower power and frequency is the key to obtaining regular honeycomb structures in laser machining. The laser focal point significantly affects the light transmittance of glass, while the feed rate has little effect. The water droplet contact angle was measured to evaluate the hydrophilicity of glass specimens with different dimensions of microstructure. It was found that the contact angle decreased with reduction of the honeycomb structure size.