The high-refractive index contrast (▵n ~0.65 as compared to silicon oxide) of Tantalum pentoxide (Ta2O5) waveguide allows strong confinement of light in waveguides of sub-micron thickness (200 nm). This enhances the intensity in the evanescent field, which we have employed for efficient propelling of micro-particles. The feasibility of opto-fluidics sorting of different sized micro-particles based on their varying optical propulsion velocity is suggested. Optical propulsion of fixed red blood cells (RBC) with velocity higher than previously obtained is also reported. The optical propulsion velocities of RBC in isotonic solution (0.25 M sucrose) and water have been compared.© (2010) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.