Patterning ultrafine metal nanoparticles using optoelectronic tweezers (OET)

When the dimensions of particles approach the nanoscale, either in one dimension for thin films, two dimensions for nanowires or three dimensions for nanoparticles, their physical properties can diverge from those of bulk materials due to quantum effects. There are many potential applications for devices based on these materials. However, it is a challenge to manipulate nanoscale materials because of their ultra-small sizes. In this paper, optoelectronic tweezers (OET) are used to trap and manipulate micro/nanoscale metal particles. Metal particles with scales from tens of microns to several nanometres were successfully manipulated and nanoscale metal particles were assembled into tailored patterns. Due to the strong electrical forces induced by the OET device, metal nanoparticles were deposited onto the surface of the amorphous silicon. After removing the liquid from the OET device, these nanoparticles were attached firmly on the sample surface through Van der Waals forces which could lead to a method of producing solid-state electronic/optoelectronic devices.