Performance evaluation and comparison of a serial–parallel hybrid multichamber piezoelectric pump

To improve the output capability of piezoelectric pumps, researchers have made an attempt to combine multiple single-chamber pumps either in series or in parallel. In this article, a serial–parallel hybrid multichamber piezoelectric pump is presented. The novel serial–parallel hybrid multichamber piezoelectric pump structure is characterized by the simultaneous occurrence of serial/parallel forms through a combination of synchronous and asynchronous modes of piezoelectric actuators. Moreover, the pump can be operated in multiple working modes to obtain the desired chamber volume and number through different serial–parallel configurations. The performance characteristics of the pump with various serial–parallel hybrid combinations were experimentally investigated and evaluated using a quintuple-chamber pump at 90 V with a frequency range of 60–400 Hz. Experimental results showed that the characteristics in terms of flow rate and backpressure changed significantly with different serial–parallel modes. Nevertheless, the backpressure presented very similar characteristics for the serial–parallel hybrid multichamber piezoelectric pump with the same number of in-phase parallel actuators. Meanwhile, the frequency-dependent flow rate characteristics were approximately similar for those pumps with symmetric serial–parallel combinations. It was found that the flow rate and backpressure mainly depended on the actuation frequency and serial–parallel modes, respectively. Compared with the quintuple-chamber pump with full out-of-phase actuators, the maximum powers of the serial–parallel hybrid multichamber piezoelectric pump with two, three, four, and five in-phase actuators were decreased by 21.1%, 51.4%, 77.7%, and 94.4%, respectively.