Abstract：Static contact angle is an important index of material hydrophobicity, but it is difficult to be obtained automatically and accurately. In this paper, droplet edge is obtained automatically by geometric active contour model based on the level set method after the droplet figure is obtained. The level set method obtains the droplet edge by solving partial differential equation, and if the droplet figure is relative clear, then the edge can be obtained relative accurately. If the volume of droplet is small, the edge of droplet figure is a part of circle. Then the obtained edge is divided into arc part and horizontal line part according to certain rule. The circle center, radius and vertical coordinates of horizontal line are obtained by least square fitting method according to coherent equation, and the static contact angle is calculated by circle parameters and intersection point of air, liquid and solid. The method is applied to simulated and real droplet figure of (room temperature vulcanization RTV) silicone rubber coating, and the result is compared to the method in which the edge is obtained manually, and the result indicates the proposed method has high accurate. The proposed method is helpful for study of automatic and accurate measurement of static contact angle.
徐志钮, 律方成, 李和明. 基于水平集的接触角算法及在RTV憎水性检测中的应用[J]. 电工技术学报, 2010, 25(12): 30-35.
Xu Zhiniu, Lü Fangcheng, Li Heming. Contact Angle Algorithm Based on Level Set and Its Application in RTV Silicone Rubber Hydrophobicity Detection. Transactions of China Electrotechnical Society, 2010, 25(12): 30-35.
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2010, Vol. 25 
