Isolating biological or biochemical content in aqueous droplets within an immiscible oil medium on a microfluidic device allows samples to be transported without cross-contamination or dispersion. But generating droplets at a suitably high speed with precise volume control has been a challenge.
Now Pei-Yu Chiou and Sung-Yong Park from UCLA have developed a pulse laser-driven droplet mechanism that allows droplet formation of up to 10000 droplets per second with controllable volumes between 1-150 pL and >1% volume variation.
Their device (shown below) consists of two microfluidic channels connected by a nozzle-like opening. A highly focused intense laser pulse induces a rapidly expanding cavitation bubble to push the nearby water into the oil channel for droplet formation.
This HOT article is free to access until the end of March – so download it today and see how they did it!
High-speed droplet generation on demand driven by pulse laser-induced cavitation
Sung-Yong Park, Ting-Hsiang Wu, Yue Chen, Michael A. Teitell and Pei-Yu Chiou
Lab Chip, 2011, 11, 1010-1012