抄録
Induced flows in water droplet mixed fine solid particles and particles motion by laser irradiation are discussed in this paper. Laser trapping system for micro-sized objects was constructed. The system contains YAG laser and optical microscope. The flows and motion of the particles in water droplet on glass plate were occurred under the microscope by laser irradiation. The trapped particles near the bottom of the water droplet were forced from the outer boundary of trapping area to center of the area. The absorption should be effective for the high intensity laser power at a focal spot on glass plate while the absorption of the near infrared laser beam into the glass plate and water can be generally small as they have high transmissivity. A micro heat spot could be produced by the absorption of the laser beam, and heat transfer occurred from the heated glass plate to the water droplet with the particles. The local flow was induced by the heat transfer in the water droplet, and the induced motion of the particles was arisen by the effect of the flow.
