Flexural deformation analysis of circular bimorph for piezoelectric pumps
SUN Xiao-Feng, YANG Zhi-Gang, SHAO Ze-Bo, DUAN Hao, JIANG Bin
(1. Department of Machinery and Electricity Engineering, Jilin Institute of Chemical Technology, Jilin, Jilin 132022, China; 2. College of Mechanical Science and Engineering, Jilin University, Changchun, Jilin 130025, China; 3. Development College of Agriculture University,Changchun, Jilin 130600,China)
Abstract：The deformation characteristic of a circular piezoelectric vibrator in a piezoelectric pump needs to be analyzed theoretically in order to get precise change in volume of the chamber when the pump is in operation. The whole vibrator structure was divided into two substructures, namely the threelayer composite structure in the middle, which is composed of piezoelectric ceramic, metal substrates, and the external metal substrate structure. The volume change equation of the circular piezoelectric bimorph was derived under the fixed boundary condition based on the small deflection bending theory for the elastic thin plates. The analytical results indicated that the volume change of the bimorph is related to its geometry parameters, material property constants and the driving voltage. The displacements at the centre of the piezoelectric vibrator with 35 mm diameter copper substrate and 29 mm diameter bimorph were measured by using a noncontact laser measurement system when the vibrator was driven by different DC voltages, then they were compared with the above theoretical results to verify the equation proposed. It was confirmed that the analytical solutions are consistent with the measurements with an around 20% error. According to the equation above, if the single chamber of a piezoelectric pump is made of that piezoelectric vibrator measured, the predicted volume change of the pump will be nearly 128.81 mm3 and with 3 091 mL/min maximum output flow rate when the vibrator is driven by a sinusoidal voltage signal (110 V, 200 Hz).
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