Speaker: Sai Chaitanya Nudurupati

Advisors: Dr. Pushpendra Singh, Dr. Nadine Aubry

In this presentation, the role of electrostatic particle-particle interactions in the dielectrophoresis of microparticles is investigated both numerically and experimentally. Experiments are performed with viable yeast cells in microelectrode structures. The relative importance of electrostatic particle-particle interactions and dielectrophoretic force is determined by the magnitude of a parameter, P₄, which is the ratio of the electrostatic particle-particle interactions and dielectrophoretic force. When this ratio is of order one, particles are seen to form interparticle chains, and collect at the edges of the particles forming long cains perpendicular to the electrode edges. When this ratio is much less than order one, no particle chains are formed and particles are seen to agglomerate at the edges of the electrodes.

1. Electrohydrodynamics of yeast cells in traveling electric fields, J. Phys. D:Appl. Phys. 39

2. Effect of Frequency and Electrode Configuration on Particles Subjected to traveling electric fields, ASME. FEDSM2006-98448

3. J. Kadaksham, P. Singh and N. Aubry, Manipulation of Particles Using dielectrophoresis, Mechanics Research Communications, to appear (2005).

4. J. Kadaksham, P. Singh and N. Aubry, Dielectrophoresis induced clustering regimes of viable yeast cells, to appear in Electrophoresis (2005).