Enhanced dielectrophoresis of nanocolloids by dimer formation

¹  Laboratory of Physics and Helsinki Institute of Physics, Helsinki University of Technology - Espoo, Finland
²  Memphys-Center for Biomembrane Physics, University of Southern Denmark - Odense, Denmark
³  Institute of Physics, Tampere University of Technology - Tampere, Finland
⁴  Department of Applied Mathematics, The University of Western Ontario - London, Ontario, Canada

Corresponding authors: emppu.salonen@hut.fi emt@fyslab.hut.fi vattulai@csc.fi mkarttu@uwo.ca

Received: 17 January 2007
Accepted: 10 April 2007

Abstract

We investigate the dielectrophoretic motion of charge-neutral, polarizable nanocolloids through molecular dynamics simulations. Comparison to analytical results derived for continuum systems shows that the discrete charge distributions on the nanocolloids have a significant impact on their coupling to the external field. Aggregation of nanocolloids leads to enhanced dielectrophoretic transport, provided that increase in the dipole moment upon aggregation can overcome the related increase in friction. The dimer orientation and the exact structure of the nanocolloid charge distribution are shown to be important in the enhanced transport.