Droplet manipulation using an optoelectrofluidic device integrated with microchannels

Abstract

This paper presents a new channel-integrated optoelectrofluidic device capable of generating and programmable manipulating nanoliter-size droplets suspended in a continuous oil phase based on the optically induced dielectrophoresis (DEP) in a liquid crystal display (LCD)-based optoelectronic tweezers (OET) system. Microfluidic generation as well as the optoelectrofluidic transport and merging of droplets have been performed simultaneously on a single device. In order to generate droplets, we integrated poly(dimethylsiloxane) (PDMS) microfluidic channels into a film-based optoelectrofluidic device. We selectively perforated the PDMS membrane to expose the photoconductive surface for manipulating the emerged droplets using optically induced DEP. Based on this novel optoelectrofluidic device integrated with a microfluidic channel, we could continuously generate, manipulate and merge droplets using the optically induced virtual electrodes constructed by an LCD-light pattern. Also, we have achieved multiple droplet manipulation and demonstrated merging two different droplets. This novel platform may be a widely usable for parallel and high-throughput biological and chemical applications based on the droplet-based optoelectrofluidics.