Microfluidic chip having on-chip electrically tunable high-throughput nanophotonic trap

Abstract

In one implementation, a microfluidic device based on optical trapping of particles is disclosed to include a substrate structured to include a fluidic channel which can carry a fluid having particles; and an optical waveguide loop formed on the substrate to include one or more waveguide sections that reside within the fluidic channel, an input optical port for the optical waveguide to receive an input optical beam, and an optical power splitter coupled to the optical waveguide loop to split the received input optical beam into two counter-propagating optical beams that prorogate in the optical waveguide loop in opposite directions and interfere with each other to form standing optical waves in at least the one or more waveguide sections that reside within the fluidic channel to optically trap particles at or near a surface of the one or more waveguide sections that reside within the fluidic channel. This device further includes an electrically controllable phase control device formed on the substrate and coupled to a location of the optical waveguide loop and operable to control an optical delay experienced by guided light at the coupled location, wherein the electrically controllable phase control device is configured to respond to an electrical control signal to adjust an amount of the optical delay at the coupled location to cause a shift in locations of nodes of each optical standing wave to change trapping locations of the trapped particles in the fluidic channel.