Numerical model for predictive high yield assembly of Cobalt nanowires using floating electrode dielectrophoresis

The isolation and manipulation of individual nanomaterials from macroscopic agglomerates and their integration into functional systems offer a pathway to realize devices in application areas spanning spintronics, nanoelectronics, energy storage, and sensing. Recently, field-directed techniques involving bottom-up assembly of nanowire/nanoparticles have been developed that utilize external stimuli such as electric [1] , magnetic [2] , optical [3] and acoustic [4] forces. Dielectrophoresis is one of the most commonly used nano-assembly techniques involving electric stimuli to accomplish device integration at single NW or nanotube level [5] . In this paper, we present the floating electrode dielectrophoresis (FE-DEP) technique for assembly of Cobalt nanowires. In FE-DEP [6] , [7] , only one set of electrodes is connected to an assembly bias (V AC ), while the opposing set of electrodes are held at floating potential with respect to underlying substrate, which is electrically grounded, as shown in Figure 1 (a) . A Cobalt NW deposited on a silicon chip using FE-DEP over an on-chip system is shown in Figure 1(b) . To investigate the deposition of this NW, a 3D nanoelectrokinetic model is built for prediction of the nano-assembly process, considering the process parameters such as nanowire properties, dimensions, location, electrode design, applied potential and suspension properties. This model is thereafter leveraged to design/fabricate systems that advance the yield capability for single NW isolation over FE-DEP on-chip devices.