Abstract: Theoretical analysis and experimental researches are composed to study the influences of surface parameters of microgroove and microarray on contact angles. Based on the Young model for smooth surface and the models of Wenzel and Cassie-Baxter for rough surface, the novel formulas used for microgroove and microarray surfaces are proposed in this paper, firstly. Microgroove and microarray surfaces are then generated with micro end-milling operations, in which the milling cutter diameter is 0.1mm. The contact angles on machined surfaces are measured and analyzed. The results show that both microgroove and microarray machined surface have positive effect on the improvement of hydrophobic properties. The contact angle increases with the increase of the distance of micro-structures while with the decrease of micro-structure size. The contract angles of droplets on the machined surface at the vertical direction are different from that at the paralleled direction of microgroove, and they influence each other. The contact angle for droplet on the microgroove surface is more stable than that on the microarray surface. However, the contact angle for droplet on the microarray surface is larger than that on the microgroove surface. The droplet on machined microarray surface is nearly spherical.

Key words: contact angle, micro cutting, microarray, microgroove, hydrophobic