OpenDrop: Open-source Software for Pendant Drop Tensiometry & Contact Angle Measurements.

Systems where two or more fluids exist in discrete phases are ubiquitous in nature and in many manufacturing processes. The common surface (or interface) between two fluids that do not mix exists in a state of tension, an intrinsic property known as interfacial tension. The contact angle is another fundamental property of interest when the interface between two fluids is also in contact with a surface, for example a water drop resting on a leaf. The contact angle is dependent on the surface energy of the solid and describes how liquids spread on a surface – vital information for dynamic liquid-solid processes such as coating and painting.