Open optoelectrowetting droplet actuation

We present experimental realization of an open optoelectrowetting (o-OEW) device for liquid droplet manipulations. The o-OEW device is realized by coplanar electrodes and a photoconductor. The local switching effect for electrowetting resulting from illumination is based on the tunable impedance of the photoconductor. Dynamic virtual electrodes are created using projected images, leading to free planar movements of droplets. Basic operations such as transporting and merging were demonstrated. Translational speed up to 3.6 mm/s was measured. Equivalent circuit analysis shows that the operational frequency for the current setup ranges from 100 to 800 Hz. (C) 2008 American Institute of Physics.