Creation of anisotropic wetting on microstructured surfaces and control of droplets

Abstract

This paper describes anisotropic wetting on microstructured surfaces inspired by butterfly wings. Tilted pillar structures were fabricated on a glass substrate by using oblique exposure of high-viscosity thick photoresist. The effect of the surface structures on droplet behavior was investigated by changing the shape (triangle, long triangle, semicircle), fraction of surface area (1/4, 1/5, 1/6), and tilt angle (0°, 40°, 60°) . Difference in sliding angles in the tilted direction and the opposite direction were observed by changing these parameters. The maximum difference in sliding angles reached 8.4°on the long triangular pillars at 1/6 of fractional area and 60°of tilt angle