Physics Colloquium
Friday, February 5th, 2004 4 P.M.

Darren R. Link

Harvard University

Droplet formation and manipulation in microfluidic devices

The ability to engineer emulsion droplets of precise size and composition is fundamental to the development of new materials and offers great potential for the study of chemical kinetic processes. We use microfluidic devices to both generate and to further manipulate dispersions one drop at a time. One strategy for doing this is electrified flow-focusing. This technique offers two important advantages over other emulsification strategies in that it both allows for a significant reduction in the smallest drop size that can be obtained, and also it generates droplets that have an electrostatic charge that can be further used in their manipulation for droplet positioning and controlled coalescence. Additional strategies for manipulating drops involve techniques for putting drops inside of drops to create controlled multiple emulsions.