抄録
Machining process is presented to control wettability on surfaces with micro structures. The structure elements are machined by cutting with a small diameter end mill. Then, the top of the structure elements are polished using a supporting plate. Burrs on the structure elements are removed by the water jet at a low pressure. The surface structures are machined on aluminum alloy plates in the presented process. Wettability on the structured surface is measured with changing the volume of the water droplet. The contact angle on the structure element increases with the liquid volume due to the pinning effect of wetting. Then, the contact angle on the structured surface becomes larger than 90 degrees though the surface of aluminum alloy is hydrophilic. The apparent contact angle changes discretely with repeating restriction and expansion of the wet area on the surface structure.
