Modelling Sessile Droplet Profile Using Asymmetrical Ellipses

Modelling the profile of a liquid droplet has been a mainstream technique for researchers to study the physical properties of a liquid. This study proposes a facile modelling approach using an elliptic model to generate the profile of sessile droplets, with MATLAB as the simulation environment. The concept of the elliptic method is simple and easy to use. Only three specific points on the droplet are needed to generate the complete theoretical droplet profile along with its critical parameters such as volume, surface area, height, and contact radius. In addition, we introduced fitting coefficients to accurately determine the contact angle and surface tension of a droplet. Droplet volumes ranging from 1 to 300 mu L were chosen for this investigation, with contact angles ranging from 90 & DEG; to 180 & DEG;. Our proposed method was also applied to images of actual water droplets with good results. This study demonstrates that the elliptic method is in excellent agreement with the Young-Laplace equation and can be used for rapid and accurate approximation of liquid droplet profiles to determine the surface tension and contact angle.

Automated summary

A simple and easy-to-use elliptic model approach is proposed in this study to generate theoretical droplet profiles and determine critical parameters with only three specific points needed. Fitting coefficients are introduced to accurately determine the contact angle and surface tension of a droplet. Results show that this method is in excellent agreement with the Young-Laplace equation and can accurately approximate liquid droplet profiles.