Microfluidic networks

Microfluidics, with the simplicity of flow and the ease of design and fabrication of networks of channels provides for a convenient playground for experiments on dynamic systems. Two phase microfluidic systems offer a toolbox for the construction of systems that present a new class of behaviors that are both very complex and very stable. For example a system of serially coupled flow-focusing units that show oscillatory behavior with uniquely long periods that is stable against small perturbations [1], and a system of the simplest microfluidic network, that is a simple loop of microchannels, that reversibly transforms a stream of uniformly spaced bubbles into a periodic or irregular sequence of intervals between bubbles [2].
We are greatly interested in the subject of flow of droplets through microfluidic networks. The dynamics of such a flow are complicated because there are long-range interections between the droplets. These intricacies provide for complications but also route to simple logic operations on microfluidic chips [3] and to automated microlaboratories performing reactions in droplets.

[1] P. Garstecki, M. Fuerstman, G.M. Whitesides, Nature Physics, 1, 168-171 (2005)
[2] M. Fuerstman, P. Garstecki, G.M. Whitesides, Science, 315, 828-832 (2007)
[3] M. Prakash, N. Gershenfeld, Science, 315, 832-835 (2007)