Piezoelectrically actuated transducer and droplet ejector

This paper presents a variation on the design of a flextensional transducer that can be used to generate sound in air or water. By placing a fluid behind one face of the transducer, and an orifice in the center, a drop of the fluid can be ejected on demand, and for every cycle of transducer excitation. We report on an optimum design for the transducer based on finite element modelling, and we present results of ejection of water, ink, powder, and photoresist. We coat silicon wafers with photoresist with minimum waste, a very costly and expensive step in integrated circuit manufacturing. The ejector is harmless to sensitive fluids and can also be used to eject fuels, chemical and biological samples