Abstract: The present invention relates to the use colloidal particles to realize photonic and microfluidic devices. In particular embodiments, colloidal particles are used to realize microfluidic a two-way valve, three-way valve, check valve, three-dimensional valve, peristalsis pump, rotary pump, vane pump, and two-lobe gear pump. In certain embodiments, actuation of an active element in the microfluidic structure is accomplished by electrophoresis, the use of an optical trap or “tweezer”, or the application of an electric field or magnetic field. In other embodiments, the application of an electrical field to colloidal particles that are substantially constrained to two dimensional movement is used to realize wave guides, filters and switches for optical signals.

Abstract: This invention of a particle separator using laser optical pressure provides a device and method for the optical separation of microscopic particles (0.01-30 ?m diameter). Separation is accomplished through a balance of forces: light interaction (momentum transfer) with the particles of interest generating optical pressure and the viscous drag force of an opposing fluid flow. Particles of larger effective size or higher refractive index will experience a greater optical force and may thus be separated from particles with a smaller size or refractive index. Application of this new laser optical separator to biological particles including bacteria and viruses now provides a new avenue for biomedical sample evaluation. Separating based upon the intrinsic properties of the particle allows apriori identification of previously unknown or unexpected particle types. The light-induced separation of chemically different species opens important new avenues for biomedical/biochemical separation.