Optical actuation of liquid droplets has been experimentallydemonstrated for the first time using a novel opto-electrowettingprinciple. The opto-electrowetting (OEW) surface is realized byintegrating a photoconductive material underneath a twodimensionalarray of electrowetting electrodes. Contact anglechange as large as 40° has been achieved when illuminated by alight beam with an intensity of 65 mW/cm2. A micro-liter dropletof deionized water has been successfully dragged by a 4-mW laserbeam across a 1cm x 1cm OEW surface. The droplet speed ismeasured to be 7 mm/sec. Light actuation enables complexmicrofluidic functions to be performed on a single chip withoutencountering the wiring bottleneck of two-dimensional array ofelectrowetting electrodes.
展开▼
