I have been a University Lecturer in Oxford Physics since 2000. My research group works on Rotary Molecular Motors, In particular the Bacterial Flagellar Motor and ATP synthase. The aim is to try and understand how these living machines work.
We use a range of techniques. Optical tweezers (3-D laser trap) and optical spanners (optical angular momentum) are used to push single motors around, via "handles" such as the bacterial cell body or gold or polystyrene spheres. These handles one micron or less in diameter, compared to ten nanometres or so for the motors themselves. We measure the position of the handles with nanometre and sub-millisecond resolution using fluorescence microscopy, laser dark-field microscopy and laser interferometry. We also use single-molecule fluorescence microscopy to detect separate components of the motors and assess how they interact with each other. By measuring the torque generated by the motors under all sorts of different conditions, we aim to arrive at a model of how they work. We are also developing a range of new techniques including digital holographic microscopy, lipid bilayer systems for single-molecule microscopy, microfluidics and lithography and synthetic biology.