A microfluidic device with integrated optics for microparticle switching

Abstract

We report a high efficiency and noninvasive microfluidic particle switching device with integrated optical microstructures. Microfluidic channels are combined with a cylindrical microlens and an optical fiber to achieve on-chip optical switching of colloidal particles without the need for an optical microscope. A laser beam is coupled into an optical fiber and redirected by the microlens. The angle of incidence of the optical force can be changed by varying the position of the optical fiber relative to the microlens. Under certain circumstances, a switching efficiency approaching 100% was achieved with a relatively fast response time for a solution containing 10 μm polystyrene spheres. © 2010 American Institute of Physics.