Optofluidics refers to a class of microscale devices that integrate both optical and fluidic components within them. The fluidic component can be used to affect the optical behavior in these devices and vice-versa which gives rise to many interesting applications for such systems. In this talk I will discuss two such optofluidic systems that I have developed with relevance to nanobiotechnology.  Primarily I will focus on my work towards the development of Nanoscale Optofluidic Sensor Arrays (NOSAs), which is an optofluidic architecture for performing label-free, highly parallel, detection of biomolecular interactions in aqueous environments. This platform is based on the use of arrays of 1D photonic crystal resonators which are evanescently coupled to a single bus waveguide. Each resonator has a slightly different cavity spacing and is shown to independently shift its resonant peak in response to changes in refractive index in the region surrounding its cavity.  I will show that the subtle effective change in refractive index caused by the binding of a small number of molecules is sufficient to impart a relatively large change in the resonance condition.  A special two stage micro-/nanofluidics architecture is used to first functionalize the devices and then to deliver the targets. I will demonstrate through numerical simulation that the advantage of this architecture lies in its potential for low mass limit of detection which is enabled by confining the size of the probed surface area. Initial experimental results for the detection of viral RNA of Dengue virus will also be presented.  In addition to this work I will also briefly present my work related to optofluidic transport in liquid-core waveguiding structures and its potential application towards highly sensitive optical chromatography separations.

Sudeep Mandal is a third year Applied and Engineering Physics Ph.D. student working under Prof. David Erickson in the Sibley School of Mechanical and Aerospace Engineering. He was awarded the Trevor R. Cuykendall Memorial Award for outstanding teaching assistant (2005-2006) in the School of Applied and Engineering Physics. His research interests lie in the field of optofluidics and the engineering of photonic devices for biological applications. In his free time he enjoys rock climbing, 3D animation and chocolates.