Local electrophoresis deposition of nanomaterials assisted by a laser trapping technique

We describe a novel local deposition technique for nanoparticles using electrophoresis deposition assisted by laser trapping. A solution containing nanometer scale colloidal Au particles was placed between a conductive substrate and a cover glass coated with an indium thin oxide film. Laser spots focused on the substrate gathered the nanoparticles around the spots, and the nanoparticles were then deposited on the substrate by controlling the electric potential between the substrate and the cover glass. A dots array and line patterning of the deposited Au nanoparticles were successfully demonstrated. Furthermore, by using a solution containing colloidal DNA, we were able to obtain a dots array of the DNA. This technique will be very useful for applications in micro-and nanodevices.