Continuous optoelectrowetting for picoliter droplet manipulation

Abstract

We report on a continuous optoelectrowetting mechanism enabling continuous high spatial resolution optical modulation of electrowetting effect on a featureless planar photoconductive amorphous silicon surface. Dynamically patterned “virtual electrode” switches voltage between the amorphous silicon layer and the dielectric layer for contact angle modulation. This device is particularly attractive for manipulating picoliter droplets. We have experimentally demonstrated trapping and moving of 10 and 50 pl droplets at a speed of 1 mm/s using a light beam.