Direct assembly of nanoparticles for large-scale fabrication of nanodevices and structures

Non-uniform electric fields are utilized to direct the large scale assembly of colloidal nanoparticles in nanoscale structures over large areas. Using micro- and nanoscale templates, various nanoparticles can be directly assembled into parallel wires, cross-wires, and many other complex structures. The assembly process is controlled by electric field, time, and geometric design of templates. The results show that single nanoparticle wires as small as 10 nm wide and 100,000 nm long as well as other nanoparticle structures can be fabricated using electrophoresis over a large area. In addition, the directed assembly of polymeric and conductive nanoparticle nanowires and networks has been demonstrated using dielectrophoresis. The nanoparticle wires can be further oriented along the direction of an externally introduced hydrodynamic flow. The presented technique is a promising approach for large scale manufacturing of nanoscale devices for many applications including biosensors and nanoelectronics.