Gold Nanoparticle Super Assembly by Dielectrophoresis

Dielectrophoretic assembly of nanoparticles has great utility in creating intricate designer nanoscale structures. Dielectrophoresis of gold nanoparticles has been used to create nanowires for electronics, high surface area electrodes for sensors, and nanoelectrode nanogaps for molecular electronics. Despite the utility of this technique, little is known about the mechanisms governing different assembly morphologies. This study combines experimental dielectrophoretic capture of gold nanoparticles suspended in water with a theoretical overview of the forces influencing deposit morphology. We used a planar electrode geometry and studied the assembly process using transmission electron microscopy. It appears AC electroosmotic fluid flow and the electrical double layer have a major influence on deposit morphology.