Aqueous droplet manipulation by optically induced Marangoni circulation

The manipulation of picoliter droplets is demonstrated using optically induced microscale circulatory flows. The circulation results from Marangoni effects induced by optical heating from light patterns created by a computer projector. Manipulation of single droplets and parallel manipulation of multiple droplets are achieved with induced forces of up to 1 nN and an average resolution of 146.5 mu m.