FIG. 4.

(a) Trajectories of a 6 μm radius particle with variable $Re\{K_{\mathit{C}\mathit{M}}\}$ and an entrance altitude 16 μm subjected to DEP and hydrodynamic forces as obtained from COMSOL simulations. The trajectories are used to estimate the altitude of the particle after DEP actuation for different values of $Re\{K_{\mathit{C}\mathit{M}}\}$ ranging from −0.4 to +0.4. (b) Simulation results of the amplitude of the square of the electric field over the sensing electrodes for different exit altitudes. The capacitance change of a pair of sensing electrodes due to a particle is directly proportional to |E^RF|² at its center. (c) Capacitance change of the second sensing electrode pair (after DEP actuation) versus altitude as obtained from Eq. (3). This curve is used to calculate the force index corresponding to different values of $Re\{K_{\mathit{C}\mathit{M}}\}$.