Dissipative forces in the electrowetting-induced Cassie-Wenzel transition on hydrophobic rough surfaces are explored. High-speed imaging of droplet shape evolution during the elec- trically induced spreading process allows for the location of the contact line to be tracked as a function of time. A surface energy analysis quantifies the total energy dissipated via nonconservative forces during the spreading process. Though identified as the dominant dissipative effect in droplet spreading on smooth surfaces, contact line friction is shown to have a relatively weak influence on the spreading on rough surfaces. Supplemental files are available for this article. Go to the publisher’s online edition of Nanoscale and Microscale Thermophysical Engineering to view the free supplemental file.


electrowetting, Cassie-Wenzel transition, contact-line friction, Dissipative forces, surface energy

Date of this Version




Published in:

C. P. Migliaccio and S. V. Garimella, “Dissipative Forces in the Electrowetted Cassie-Wenzel Transition on Hydrophobic Rough Surfaces,” Nanoscale and Microscale Thermophysical Engineering, Vol. 16, pp. 154-164, 2012.