Dielectrowetting Driven Spreading of Droplets

The wetting of solid surfaces can be modified by altering the surface free energy balance between the solid, liquid and vapour phases. Here we show that liquid dielectrophoresis (L-DEP) induced by non-uniform electric fields can be used to enhance and control the wetting of dielectric liquids. In the limit of thick droplets, we show theoretically that the cosine of the contact angle follows a simple voltage squared relationship analogous to that found for electrowetting-on-dielectric (EWOD). Experimental observations confirm this predicted dielectrowetting behavior and show that the induced wetting is reversible. Our findings provide a non-contact electrical actuation process for meniscus and droplet control