Microscopic structure of electrowetting-driven transitions on   superhydrophobic surfaces
  We investigate directly at the microscale the morphology of the electrowetting induced transition between the Cassie-Baxter and Wenzel states for a water droplet on a superhydrophobic surface. Our experiments demonstrate that the transition originates in a very narrow annular region near the macroscopic contact line, which is first invaded by water and causes a thin film of air to be entrapped below. At high applied voltages, a growing fraction of microscopic air-pockets collapse, resulting in a partialWenzel state. Modulations in the intensity of the light reflected from individual micro-menisci clarify that the local contact angles near the filling transition are close to the usual advancing values for contact lines on smooth surfaces. 
A. Staicu, G. Manukyan, and F. Mugele