Automated contact angle measurement of non-spherical sessile drops with a shape analysis method
Aurélien Stalder
Section Microtechnique, EPFL
Semester project February 2004
Abstract
Contact angle is a well-known technique for investigating and controlling adhesion, surface treatments and cleaning. Today, the most widely used method to measure contact angles is the triple point method. As mentioned in its name, this method takes into consideration only three particular points on the contour of a drop to calculate contact angles. What's more it neglects gravity effects and supposes that drops are spherical. In this project, we are using advances in computer imaging to measure precisely contact angles. We use the whole contour of the drop, and a Laplace based physical model that takes gravity into account to calculate contact angles.
Figure: Contour detection and contact tangents of a non-spherical drop