  The present study aims at utilizing field effect phenomenon to induce
heterogeneous surface charge and consequently changing the fluid flow in a
solid state nanochannel with converging-diverging periodicity. It is shown that
the proposed geometry causes non-uniform radial field adjacent to channel walls
which is stronger around the diverging section and weaker next to the
converging part of the wall. The later generates heterogeneous surface charge
at channel walls depending on the applied gate potential i.e. applying low gate
potential enables effective modulation of surface charge with the same polarity
of the intrinsic charge at channel walls, while moderate gate potential causes
charge inversion in diverging sections of the channel and generates reverse
flow and thus results in fluid flow circulation. The potential application of
flow circulation for trapping and rejection of particles is also demonstrated.
