piezoactuator, micro compressor, hydraulic drive, diaphragm
A low volumetric efficiency and low actuation force are the two disadvantages of a diaphragm-type piezoactuated micro compressor. A hydraulic drive was introduced to the micro compressor for the sake of improving its volumetric efficiency and actuation force. The hydraulic oil was driven by the piezoactuator and transferred the actuation force to a flexible diaphragm, which compressed the fluid in a domed cavity. Analytical solution was derived to predict the performance (pressure rise and flow rate) of the micro compressor. The solution included large deflections of a flexible diaphragm under a uniform pressure load and non-linear deflections of a diaphragm-type piezoactuator under loads of voltage and pressure, which considered the geometrically nonlinearity as well as the electrostrictive and electroelastic effect of the piezodisc. The energy minimization method and Rayleigh-Ritz method were employed to solve the solution of the piezoactuator. Energy associated with the solution includes elastic potential energy of the deflecting piezoactuator, electric potential energy in the piezodiscs, and compression work done to the fluid. The proposed solution concerning the deformation of the piezoactuator and the flexible was validated via experimental measurements. Based on the analytical theory, the pressure rise vs. flow rate relationship was investigated for the gas micro compressor with a specific cavity volume. The results showed that the maximum pressure ratio the micro compressor was 1.46 at the driving voltage of 100 V when the suction gas pressure was 1bar.