A resonant piezoelectric stack pump based on a two-stage nested rhombus displacement-amplifying vibrator in symmetric-drive mode

This paper proposes a resonant piezoelectric stack pump based on a two-stage nested rhombus displacement-amplifying vibrator in symmetric-drive mode. Two rhombus displacement amplifiers are connected in a nested manner to achieve exponential displacement amplification of the piezoelectric stack. Symmetric-drive mode is adopted to minimize the vibrating mass and inertial load in the displacement output direction of the piezoelectric vibrator, thereby improving its resonant frequency. A piezo-actuated two-stage nested rhombus displacement-amplifying vibrator was designed, and its output characteristics in fix-drive mode and symmetric-drive mode were analyzed theoretically and by finite element simulation. Two piezoelectric pumps were designed and fabricated with the same piezoelectric vibrator in fix-drive mode and symmetric-drive mode respectively, and their output performances were tested and compared. Under a sinusoidal driving voltage of 80 V, the piezoelectric pump in fix-drive mode achieved the maximum flow rate of 168.8 ml/min at the resonant frequency of 201 Hz and the maximum backpressure of 7.4 kPa at 203 Hz; while the maximum flow rate and backpressure of the piezoelectric pump in symmetric-drive mode reached 792.2 ml/min and 35.6 kPa at the corresponding resonant frequencies of 660 and 721 Hz.