Flows with Tunable Micro- and Nano- Structure at Short Diffusion Timescales: Towards the Development of a Liquid Photonic Bandgap Material

Microfluidic flow is subject relatively low inertial forces versus viscous forces and therefore exhibits laminar characteristics. This creates predictable streamlines, where mixing occurs only via diffusion. We have capitalized on this flow to create a class of microfluidic system that creates a tunable structure based on channel geometry and flow conditions. With this system, we have demonstrated the ability to create sub-micron fluid structure with fast tunable response times. We have also shown the ability to create structure with unique anisotropy by changing microflow conditions. This has been used to create a periodic flow structure of alternating refractive index fluids. This flow has also been analyzed and probed in an integrated optofluidic system for tunable bandgap applications.