Sessile Drop

The sessile drop is the standard arrangement for optical measurement of the contact angle using drop shape analysis.

Background

In the case of the static contact angle, the deposited drop lies on the surface of a solid.

 

In the case of the dynamic contact angle, the size of the drop is increased (advancing angle) or reduced (receding angle) during the measurement by means of a needle immersed in the drop, or moved over the solid with the help of a tilting table.

Sessile drop and its reflection on the surface of a solid