  This fluid dynamics video showcases how optically induced electrowetting can
be used to manipulate liquid droplets in open space and particulate phases
inside the droplet. A photoconductive layer is added to a conventional
electrowetting-on-dielectric (EWOD) structure to generate light enabled virtual
electrodes, hence resulting in an eletrowetting action. Coplanar electrodes
deployed alternately on a substrate enable open droplet manipulations
differentiating from a sandwiched configuration. An integration with an
optoelectric method shows dynamic and rapid particle handling by strong micro
fluidic vortices in conjunction with other electrokinetic forces inside a
droplet. The droplet manipulations are realized with visible illumination and
powered at 150 volts peat-to-peak with a low frequency (100 Hz-800 Hz). The
particle concentration is achieved on the surface of the same chip but
illuminated with a near-infrared (1064 nm) light source and biased with a high
frequency (24 kHz) AC signal.
