Abstract
Dropwise condensation(DWC) has high heat transfer coefficient. However, DWC may no maintain long period. In order to maintain DWC long enough, it is important to understand the effect of the surface condition. In the present paper, wettability of metal-sputtered surfaces was controlled by MEMS technology. The effect of several metal-sputtered surfaces, i.e., Cupper(Cu), Titanium(Ti), Silver(Ag) and Chromium(Cr) respectively, and the on the pattern of the condensation, i.e., DWC or FWC, was examined qualitatively. The surface condensation with sputtered thin Silver(Ag) and Chromium(Cr) films were DWC. On the other hand, the surface condensation with sputtered thin Cupper(Cu) and Titanium(Ti) films were FWC. When equivalence contact angle was over 72 degree, DWC was found. The other hand, when the angle was under 62 degree, FWC was observed.
