Particles sorting in micro-channel system utilizing magnetic tweezers and optical tweezers

This is a research on classifying magnetic micro-particles in a micro flow tunnel, using an embedded inverted-laser tweezers system, a micro-flow pump and a micro-magnet. Manipulation of the particles in the micro-flow tunnel was achieved. An image recognition system integrated in the micro-flow tunnel was used to identify, count and separate different particles precisely using the laser and magnetic tweezers. In addition, the polystyrene particle classification experiment showed that the good separating result when the continuous flow and magnetic tweezers were used as manipulating forces. The higher the flow velocities were, the larger the separating rate would be, and thus, the largest separating rate was 80% in the study. When the continuous flow and laser tweezers were used as manipulating forces, the polystyrene particle separating rate could be 90%. When the laser tweezers and magnetic tweezers were used, it showed that laser tweezers was the most effective in trapping polystyrene particles when flow velocity were 0.08 to 0.25μm/s. The separating rate of the polystyrene particles could be as high as 95%, and the separating rate of the magnetic particles could also be as high as 85% when the flow rate is around 0.08 to 0.17μm/s.