Picoliter droplet manipulation based on a novel continuous opto-electrowetting mechanism

We report on a novel continuous opto-electrowetting (COEW) mechanism which enables surface wetting property to be modified locally by an optical beam with a spatial resolution of a few micrometers. It is based on the opto-electrowetting mechanism we reported previously, but without using any pixilated electrodes. The COEW is particularly attractive for manipulating picoliter droplets. We have experimentally demonstrated the trapping and moving of 10 and 50 picoliter droplets. The experimental results agree very well with our theoretical modeling. The COEW device consists of four featureless layers of thin films and does not require any photolithographic process. Disposal COEW devices can be mass-produced at very low cost.