Piezoelectric gas flow controller based on dual-bimorph actuators

In this paper, we present our study on a piezoelectric gas controller based on dual-bimorph piezoelectric valve [1]. The bimorph structure was designed to be a one-dimensional plate to reduce the overall size of the piezoelectric actuator. A rod was placed at the center of a pair of piezoelectric bimorphs, and the piezoelectric valve was slightly compressed to create a pre-stressed condition. These two piezoelectric bimorphs were synchronized to push the cylinder valve to initiate valving process. The performances of this system were studied and evaluated, including frequency response, pressure drop, and flow rate. The piezoelectric actuator was fabricated by attaching two 5 mm wide, 50 mm length and 0.4mm thick bimorph PZT together. The poling direction of the two PZT layers was in opposite direction to create a serial bimorph. PMMA cylinder were created by using a CO₂ laser cutter. The level of the valving movement was studied under a different driving voltage and operating frequency. Preliminary finding showed that a 0.103mm displacement at 1 Hz can be achieved and the developed piezoelectric valve can be used to control output pressure.