Right Type Departmental Bulletin Paper

In previous work [1] we reported that directed forward and backward motion of an oil droplet floating in an aqueous solution can be generated by using a laser beam. This motion is caused by local heating that induces a specific mode of steady convection inside the droplet ， and this generated convective motion produces translational directed motion of the droplet. In the present study ， we performed experiments on a nitrobenzene oil droplet in a water solution under strong laser irradiation. Pulsating motion of an oil droplet ， with aluminium powder inside，日oatingin an aqueous solution is generated by using a continuous laser beam. This oscillation is caused above a certain critical power of the laser ， and above this value the frequency increases almost linearly with the power. Figure 1 shows the floating geometry of a droplet in an narrow cylindrical glass vessel. The laser beam is aimed at the oil droplet from above. The oil droplet pulsates (or oscillates) depending on the laser power: the higher power of the laser is the faster droplet oscillates. Figure 1: Schematic diagram of the experime 此 ac.w. laser beam irradiates the droplet (approx. 5 mm indiameter) from above. For greater detail ， inFig. 2 we show a spatiかtemporalplot of the oil droplet movemen