The objective of this proposal is to develop a multifunctional far-field nanoscopic platform based on stimulated emission depletion (STED) and laser induced fluorescence photobleaching anemometer (LIFPA), which will enable the development of nanovelocimeter, nanothermometer and nanofluorescence spectroscopy respectively for measurement of spatial distributions of flow velocity, temperature and concentration in nanofluidics and near-wall flow within 100 nm. STED is applied to break diffraction limit to achieve high spatial resolution and molecular tracer based LIFPA is used to overcome issues with nanoparticles as flow tracer in nanochannel. Currently this team is one of few groups in the world that have the extensive experience in developing sophisticated STED system for nanophotonics application. They have recently developed, for the first time, a far-field non-invasive nanovelocimeter built upon single wavelength continuous wave (cw) laser STED and LIFPA for velocity profile measurement in a subnanometer channel.
However, due to limited resources, the current spatial resolution is limited to 70 nm and the system can be used for few dyes and proteins. The system is difficult for non-expert users. To further advance this technology, they propose to develop a novel system having tunable pulse lasers integrated with confocal microscope, so that the spatial resolution of the system can be ~ 5-10 nm. It will have more functions and broad applications and is easy to use. The proposed instrumentation will rely on existing interdisciplinary collaborative efforts from the College of Engineering and Computing, College of Art and Science, and the School of Medicine.
