ABSTRACT
Microdroplet generators are becoming an important research area in MEMS (microelectromechanicalsystems), not only because of their historically valuable marketing device, the ink-jet printhead, but also because of many other emerging applications in precise-or micro-amount fluidic control. The history of microdroplet generators began with the idea’s inception by Sweet (1964, 1971) using piezo actuation. In the late 1970s HP and the Cannon Corporation [Nielsen et al., 1985] began using thermal bubble actuation. Since then, numerous research activities regarding ink-jet applications have been conducted. Recently, with the emerging applications in biomedicine, fuel injection, chemistry, pharmaceuticals, electronic fabrication, microoptical devices, IC cooling, and solid free form, much research has focused on microdroplet generators. Thus, many new operation principles, designs, fabrication processes, and materials related to microdroplet generation were explored and developed during the last decade.
