Utilization of Nano-Deep Evanescent Field for Particles Optophoresis

Abstract

Separation and sorting of microparticles have set foot in critical diagnostics, advanced chemical and biomedical assessment. By utilizing specific characteristics for sorting, various techniques have been developed and optimized. Evanescent field optical trapping of microparticles is one of the emerging technologies to sort and separate in a non-mechanical and non-destructively several particles simultaneously. This paper describes the studies carried out, both theoretically and experimentally, to optimize the propulsion of polymer particles on copper ion-exchanged channel waveguides, to ultimately allow for the trapping and separation of mammalian adipose tissue derived stem cells (AT-SCs) according to their size and refractive index. The propulsion of polymer particles was observed to increase with the supplied input power and with laser polarization at transverse electric (TE) mode. The propulsion of particles was demonstrated to peak on a 4μm channel width of a 1μm thick copper ion-exchanged waveguide. The work carried out provides the optimal optical and waveguide parameters to be exploited for trapping and sorting AT-SCs on copper ion-exchanged waveguides.