A superhydrophobic surface patterned with hydrophilic channels for directional sliding control and manipulation of droplets

Abstract

Abstract Rapid and controllable sliding of droplets on anisotropic superhydrophobic surface has significant meaning in advanced science and technologies, thus being widely studied in recent years. Herewith, we reported a fabrication of micro- and nano- fractal superhydrophobic surface patterned with micro hydrophilic channels using laser direct writing method. The sliding angle of droplets in the direction parallel to the channels is as low as 8°. While, in the perpendicular direction, droplets exhibit rather high sliding angle, even being pinned to the surface that is tilted to fully upright (sliding angle to be 90°). Such significant anisotropic property enables droplets slide along the pre-assigned stripe-shaped patterns rapidly and steadily, when a droplet is released on a slope. The guidance action still works even when the surface is inverted. Consequently, the patterned surface is suitably designed as a novel droplet manipulate device, which easily achieves effective weight lossless transportation of droplets.