As more is understood about the importance of nanoparticles in biological and environmental systems, improved tools are needed for their characterisation and study. A particular challenge is the study of small nanoparticles in fluids, for which rapid Brownian motion means that without some form of immobilisation, individual particles can only be observed for a few milliseconds. Optical tweezing is a gentle form of immobilisation but can only trap particles down to about 50 nm in size.
This project seeks to use electrokinetic trapping techniques to immobilise individual nanoparticles below 50 nm in size so that they can be characterised for extended time periods. Nanoparticles will be detected via their dielectric polarisability, using optical microcavities or equivalent techniques, and their motion will be corrected using real-time feedback to electrodes to create an anti-Brownian electrokinetic (ABEL) trap.
The project will involve hands-on instrument development including device fabrication. It will be carried out in close communication with Oxford HighQ Ltd, a new spin-out from the group which is developing commercial instrumentation for nanoparticle analysis.