Droplet Interferometry: A Schlick Way to Consider Interfacial Energetics

We verify the use of an evaporating sessile water droplet as a source of dynamic interference fringes in a Fizeau-like interferometer. Experimentally-obtained interference patterns are compared with those produced by a geometrical optics-based computational model to demonstrate the potential for classical optical theory to enhance the analysis of interfacial energetics. A detailed description of the process taken to optimize fringe visibility is presented, and a comparison is made between various droplet substrates. Silicon-based substrates appear to be superior than glass-based substrates in their ability to image a clear dynamic interference pattern.