Simulation study on 3D trajectory of dielectrophoretic force assembled nanowires

Nanoscale manipulation, which assembles nanostructures towards desired positions, plays a substantial role in the fabrication of nanowire based devices. Dielectrophoresis (DEP), the motion of dielectric particles inside a non-uniform electric field, is demonstrated to be an efficient method to manipulate nanowires. However, assembly of nanowires by DEP are investigated mainly through experimental observations, very little theoretical studies have been reported so far. In this work, the 3D trajectory of single nanowire assembled by DEP in nanofluid is analyzed and simulated. Polarized in the electric field, the motion of nanowire is determined by DEP force, DEP torque, and the torque generated by DEP forces. The nanofluid, on the other hand, applies hydrodynamic drag force and drag torque to hamper the nanowire's motion. A model involving all the forces and torques is constructed to guide the simulation of the nanowire's trajectory. Depending on its initial condition, the nanowire is predicted to either bridge the electrodes or attach on the surface of one electrode.