Push/pull actuation using opto-electrowetting

It is shown theoretically and experimentally that opto-electrowetting may be used for both pulling and pushing liquid droplets. A theoretical analysis based on the Lippmann-equation and an electronic equivalent circuit model allows definition of a voltage and frequency range for which pushing may be achieved, a novelty in electrowetting-based actuation. Experimental confirmation of the effect demonstrates that enhanced flexibility in micro-fluidic actuation may be obtained under appropriate bias conditions. (c) 2007 Elsevier B.V. All rights reserved.