Dielectrophoresis (DEP) is the name given to the induced movement of polarisable particles in non-uniform electric fields. First described analytically in 1951, it has been used since 1966 for the analysis of cells and other bioparticles. It relies on (typically) micromanufactured, planar electrodes in microfluidic systems, and has been applied to study and separate a wide range of cells and other bioparticles. As a discipline it has become widely adopted around the world, with typically 400 publications on the subject in an average year; however, it has never attained widespread adoption in the target biological community, but to the complexities of implementation and interpretation of results. We aim to remedy that through development both of instrumentation and applications.
Numbers in bold refer to the papers on the Publications page.
For more information on DEP, please visit the Dielectrophoresis Network page.
My postdoctoral work comprised the first funded research study of the DEP behaviour of nanoparticles such as viruses (7) and latex beads (11-13), and led to the first demonstration of the separation of different types of viruses (10).
I continued studying this area after obtaining my lectureship, in particular developing the theory describing the effect of the electrical double layer on the DEP behaviour of nanoparticles down to the protein level (22), in particular identifying the contributions of the Debye (14) and Stern (19,20) layer conduction to nanoparticle DEP behaviour, as well as an influential review paper on the potential applications for nanotechnology (15). We have developed a method using impedance to measure the DEP behaviour of nanoparticles (specifically to differentiate semiconducting from metallic carbon nanotubes) (40) but which has proven equally good at characterising other biomolecules such as examining conduction mechanisms of AT vs GC DNA (70), studying proteins (79) and sorting silicon nanowires according to purity (80).
The last of these culminated in a technique for nanofabricating tuned nanowire devices using DEP (66,76). This body of work represents the first, most comprehensive study of DEP on the nanoscale thus performed; the findings have also substantially informed more recent studies on developing a complete understanding of the interplay of different electrophysiological measures in cells.
"Begin with the possible and gradually move towards the impossible"
- Robert Fripp, guitarist