Devices for the manipulation of a suspended particle in an electric field
gradient include a plurality of electrically isolated electrodes on a
surface. A liquid composition is on the plurality of electrodes. The
liquid composition covers the surface continuously between adjacent ones
of the plurality of electrodes. The liquid composition has an exposed
liquid surface for suspending a particle. The plurality of electrodes are
configured to provide an electric field gradient for transporting the
particle suspended in said liquid composition.