Demonstration of optical flow force of micro-objects on a coverslip-scale optical polymer waveguide

In this Letter, an optical flow force of micro-objects on a coverslip-scale optical polymer waveguide is demonstrated. The light is coupled into a coverslip-scale optical polymer waveguide with microparticles by a coupled lens, inducing whispering gallery mode in microparticles on the optical waveguide surface. The simulation and experiment show that microparticles on a coverslip-scale optical polymer waveguide are subjected to a rightward and leftward optical flow force for concentrations of 10%–80% and 90%–100% of the ambient fluid medium, respectively. This finding enables selective bidirectional manipulation of microparticles on a coverslip-scale optical polymer waveguide through controlled variation of glycerol concentration.