Related Experiment Video
Updated: Feb 4, 2026

Fabrication of Superhydrophobic Metal Surfaces for Anti-Icing Applications
Published on: August 15, 2018
Re-entrant Cavities Enhance Resilience to the Cassie-to-Wenzel State Transition on Superhydrophobic Surfaces during
Rishav Roy1, Justin A Weibel1, Suresh V Garimella1
1School of Mechanical Engineering and Birck Nanotechnology Center , Purdue University , West Lafayette , Indiana 47907 , United States.
Abstract:
Electrowetting-based droplet actuation has applications in digital microfluidics. Mobility of droplets on surfaces can be enhanced using structured superhydrophobic surfaces that offer inherently low adhesion to droplets in the Cassie state. However, these surfaces must be designed to prevent transition to the Wenzel state (in which droplets are immobile) at high electrowetting actuation voltages. The electrowetting behavior of cylindrical microposts and mushroom-shaped re-entrant microstructures, both of which afford excellent superhydrophobicity, is investigated and compared. A surface-energy-based model is employed to estimate the energy barrier for the Cassie-to-Wenzel transition and thus the electrowetting voltage required to initiate this transition. The mushroom structures are predicted to be more resilient to transition (i.e., transition occurs at a voltage that is up to 1.5 times higher) than microposts. Both types of microstructured surfaces are fabricated and electrowetting experiments performed to demonstrate that mushroom structures indeed inhibit the Cassie-to-Wenzel transition at voltages that induce such transition on the cylindrical microposts.
More Related Videos
12:22Mindfulness in Motion MIM: An Onsite Mindfulness Based Intervention MBI for Chronically High Stress Work Environments to Increase Resiliency and Work Engagement
Published on: July 1, 2015
08:02Rendering SiO2/Si Surfaces Omniphobic by Carving Gas-Entrapping Microtextures Comprising Reentrant and Doubly Reentrant Cavities or Pillars
Published on: February 11, 2020
Related Concept Videos
Phase Transitions
Properties of Transition Metals
Phase Transitions: Vaporization and Condensation
Oral Cavity
Teeth: The teeth are the hardest structures in our bodies. Humans have two sets of teeth throughout their lifetime: deciduous (baby) teeth and permanent teeth. Each tooth consists of several parts: the crown (visible part), the root (embedded in the jaw), enamel (hard outer...
Phase Transitions: Sublimation and Deposition
Cooperative Allosteric Transitions