Abstract
Mixing performance of optical micro rotors with 3, 4 and 5 paddles has been studied by computational simulations. First, a relation between laser power and optical torque acting on the rotors is analyzed. Second, fluid torque which consists of pressure and sheer stress, and the mixing rate of two kinds of fluids are calculated by solving the three dimensional Navier-Stokes equations. It is found that the optical torque caused by the laser is proportional to the laser power and the torque increases with the paddle number, that the fluid torque is proportional to the rotation speed of the rotor and this torque also increases with the paddle number, and that 4-paddle rotor produces the most mixing rate for a fixed laser power among these three rotors.
