A Dual-Chamber Serial⁻Parallel Piezoelectric Pump with an Integrated Sensor for Flow Rate Measurement

A new concept of a dual-chamber serial-parallel piezoelectric pump with an integrated sensor (DSPPIS) is presented in this paper. By means of dividing a piezoelectric bimorph into an actuator and a sensor, sensing function is integrated onto the DSPPIS for flow rate measurement. A prototype of the DSPPIS was manufactured and assembled from a finished piezoelectric bimorph. Then, frequency and voltage characteristics were tested to evaluate the performance of the DSPPIS with serial and parallel connection. Experimental results show that the optimal frequency range of DSPPIS can be achieved and determined by itself through monitoring the sensing voltage when driven by a fixed voltage of 150 Vpp and a frequency range of 40⁻400 Hz. For a fixed frequency of 100 Hz and a voltage range of 50⁻250 Vpp, both the sensing voltage and output flow rate increase with the increase of driving voltage. It is observed that there is a positive correlation between sensing voltage and output flow rate, which was further fitted by using linear function. The correlation coefficients for the DSPPIS with serial and parallel connection are calculated as 0.9716 and 0.9054, respectively. As a result, the DSPPIS demonstrated in this paper has realized the measurement of flow rate without the additional flow-sensing equipment both in serial and parallel connection.