Characterization of laterally aligned carbon nanotubes formed by AC dielectrophoresis

We investigate the relationship between the parameters of the AC electric field and the properties of dielectrophoretically aligned carbon nanotubes (CNTs) between two triangular-shaped micro-electrodes. Specifically, the effects of electrode dimensions, magnitude and frequency of the applied potential, and fluid velocity due to electrothermal force on the resultant aligned CNT trace width are examined. Parameters of the electric field are computed numerically using Ansoftreg. Both transient and steady state results are studied. The transient results shows the CNT trace grows linearly initially. This is followed by an asymptotic widening of the trace before a constant steady-state trace width is reached. The steady-state trace width (1) increases with electrode tip angle, (2) increases with increasing potential, and (3) is not affected by the frequency of the applied potential. The results of the present study provide an important guideline for designing CNT based devices fabricated by dielectrophoresis.