Controlled Transport of Individual Microparticles Using Dielectrophoresis

A dielectrophoretic device employing
a planar array of
microelectrodes
is designed for controlled transport of individual microparticles.
By exciting the electrodes in sequence, a moving dielectrophoretic
force is created that can drag a particle across the electrodes in
a straight line. The electrode shapes are designed to counter any
lateral drift of the trapped particle during transport. This facilitates
single particle transport by creating a narrow two-dimensional corridor
for the moving dielectrophoretic force to operate on. The design and
analysis processes are discussed in detail. Numerical simulations
are performed to calculate the electromagnetic field distribution
and the generated dielectrophoretic force near the electrodes. The
Langevin equation is used for analyzing the trajectory of a microparticle
under the influence of the external forces. The simulations show how
the designed electrode geometry produces the necessary lateral confinement
required for successful particle transport. Finally, experimental
results are presented showing controlled bidirectional linear transport
of single polystyrene beads of radius 10 and 5 μm for a distances
840 and 1100 μm, respectively. The capabilities of the proposed
platform make it suitable for micro total analysis systems (μTAS)
and lab-on-a-chip (LOC) applications.