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In this paper we propose a delivery method for a PZT jet pump driven by repeated impulsive force of the actuator. The pump is simple in construction being composed of only a piston-cylinder and a receiving hole, and it has no check valves. The multilayer PZT actuator pushes the piston impulsively and the fluid in the cylinder is ejected out through the nozzle forming a jet flow. The receiving hole that is placed facing the nozzle catches the jet flow and one way flow can be obtained. Experimental works indicated that the driving frequency as well as the dimensions such as the diameters of the nozzle and receiving hole was important to improve the pump performance. Moreover it was recognized that while air bubbles were apt to be generated in the cylinder during the suction stroke they were exhausted out of the cylinder at under a certain driving frequency.

This paper deals with the development of a pneumatic on/off valve driven by impulsive force of a multilayer PZT actuator. The displacement of the actuator is so small that it is necessary to design an amplifying mechanism . However, it subtracts the advantages of this actuator. On the other hand, the actuator can snap off a contacting small object like a hammer when the voltage is applied rapidly. This type of action is called a flight hammer . Using this action we hav developed an on/off valve with a nozzle-flapper mechanism, which is normally closed by the air pressure and is opened for a short time by the PZT actuator with the help of the spring force . The application of this valve is to blow off small objects by the air pulse flows that are generated by the on/off action of the valve . The air jet could blow up a small steel ball up to 20cm in height.

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