Abstract
Micro droplet collider on a chip was newly developed. Two droplets were metered by utilizing microchannel structures and hydrophobic pressure barriers called Laplace valves (LVs). One droplet was shot and accelerated from one LV by controlled air pressure. The accelerated droplet successfully collided to the other droplet, which was metered and transported to a chamber beforehand. We applied this concept to micromixer as one demonstration. Mixing of two droplets which had 1:10 volume ratio (totally ∼5 nl) was achieved within 0.5 s, which was more than 6,000-fold faster than that of molecular diffusive mixing. © 2009 CBMS.