On-a-chip surface plasmon tweezers

We report on an integrated optical trapping platform operated by simple fiber coupling. The system consists of a dielectric channel optical waveguide decorated with an array of gold micro-pads. Through a suitable engineering of the waveguide mode, we achieve light coupling to the surface plasmon resonance of the gold pads that act as individual plasmonic traps. We demonstrate parallel trapping of both micrometer size polystyrene beads and yeast cells at predetermined locations on the chip with only 20 mW total incident laser power. (C) 2011 American Institute of Physics. [doi:10.1063/1.3625936]