DOI: https://doi.org/10.15368/theses.2019.103
Available at: https://digitalcommons.calpoly.edu/theses/2095
Date of Award
6-2019
Degree Name
MS in Biomedical Engineering
Department/Program
Biomedical and General Engineering
College
College of Agriculture, Food, and Environmental Sciences
Advisor
Hawkins
Advisor College
College of Agriculture, Food, and Environmental Sciences
Abstract
A numerical simulation of electrowetting on a dielectric was performed in COMSOL to grant insight on various parameters that play a critical role in system performance. The specific system being simulated was the Open Drop experiment and the parameters being investigated were the applied voltage, contact angle at the advancing triple point, and droplet overlap onto neighboring actuated electrodes. These parameters were investigated with respect to their effect on droplet locomotion performance. This performance was quantified by the droplets velocity and the dielectrophortic (DEP) force’s magnitude; the DEP force was calculated from integration of the Maxwell Stress Tensor, however, the force was not integrated into the simulation to assist with droplet movement.
It was found that as the droplet overlap onto the neighboring electrode, or droplet radius to electrode size ratio, decreased, the droplet velocity increased. As the applied potential increased, and induced contact angle at the advancing triple point decreased, droplet velocity also increased. Both the decreasing overlap and increasing voltage had a linear effect on droplet velocity. As the droplet overlap increased, the rate of change of droplet velocity decreased as increasing voltages were considered. A 2D DEP calculation illustrated that an increase in voltage induced a tenfold increase in the corresponding DEP force; a linear relationship was found between droplet overlap and DEP force for the Open Drop size regime.