Evanescent wave-based particle tracking technique for velocity distribution in extended nanochannel

Y. Kazoe, K. Iseki, K. Mawatari, T. Kitamori
The University of Tokyo, JP

Keywords: nanochannel, flow, evanescent wave, fluorescence, nanoparticle

Summary:

We developed a flow measurement technique of velocity distribution in extended nanochannel (10- 1000 nm), using fluorescent tracer nanoparticles and the evanescent wave which penetrates into a liquid medium with an exponential decay from the channel wall. Flow velocity in the nanochannel was successfully obtained with a 30 nm spatial resolution, which is much smaller than the optical diffraction limit. This study dramatically advances basic understanding of nanoscale fluid mechanics and nanoparticle dynamics strongly affected by specific liquid structure and electric double layer, and provides important information for creation of novel fluidic devices using extended nanospace.