Abstract
A novel droplet generator equipped with flow-control has been developed for the formation of molten tin droplets. The piston with a piezoelectric crystal enables us to change the flow resistance in a narrow gap region between a liquid vessel and a nozzle, resulting in the variation of the flow velocity at a high repetition rate. The formation of tin droplets using this generator was demonstrated in a wide frequency region from 16 to 59 k Hz using a 50μm nozzle, which lies with the range of 3.9<λId<14. The separation of the piezoelectric crystal and the nozzle in this droplet generator is quite suitable for high-temperature liquids such as molten tin and for harsh environments such as those in vacuum. A flight control of water droplets was also demonstrated by electrifying the droplets.
