Method and apparatus for non-contact electrostatic actuation of droplets

An apparatus for actuating a droplet by electrowetting, comprising:

• (a) a first conductive layer comprising an array of control electrodes covered by a first hydrophobic insulator surface;
• (b) a second conductive layer comprising a second conductive layer surface facing the first hydrophobic surface, the second conductive layer spaced from the first conductive layer to define a gap therebetween, and having an actuation voltage thereon of 40 to 50 volts;
• (c) a wire traction system comprising at least one conductive elongate wire element disposed in the gap between the first and second conductive layers and comprising a second hydrophobic surface, and having a voltage thereon less than the second conductive layer actuation voltage;
• and
• (d) a voltage source communicating with the second conductive layer and the elongate wire element that provides an actuation voltage to the second conductive layer of 40 to 50 volts, wherein the droplet is caused to move along a pathway extending around the conductive elongate wire element and from the first conductive layer towards the second conductive layer.