Characteristic parameter estimation for single-particle based on dielectrophoretic and hydrodynamic effects

Dielectrophoresis (DEP) as a well-known approach to manipulate particles can be utilized in combination with fluidics to implement a measurement on characteristic parameters of particles. Numerical simulation of DEP factors was executed together with simulation of electric field distribution by means of Comsol Multiphysics. The simulation results facilitate the establishment of dynamic equilibrium model between a DEP force and a fluid drag force. According to critical release flow-rate and signal frequency of DEP, those parameters of a particle, such as permittivity, conductivity and radius, were estimated via Levenberg Maquardt iteration algorithm. The experiments validated the method and demonstrated a sensitive and consistent measure for single-particle assay.