In this study, a new micropump was designed, which is suitable for medical applications regarding size and flow rate. When a micropump is used to control the amount of drug delivery, the flow rate is a key parameter and can be controlled with the diaphragm displacement. The amount of displacement depends on the thickness of the piezoelectric element, voltage, and input frequency. The simulation results showed that the displacement of the vibrating diaphragm increased with applied voltage. Moreover, when the piezoelectric thickness was increased, vibrating diaphragm displacement also was decreased. The flow rate can be adjusted by increasing or decreasing of the input voltage. Presented results also showed that the performance of the micropump was affected by the frequency of voltage. In this study, we analysed two Lead Zirconate Titanate (PZT-2) piezoelectric actuators with 50 μm and 100 μm thicknesses. The voltage values were 10 V, 20 V, 30 V, 40 V and the frequencies were 5 Hz and 10 Hz, for 3 seconds with 1 ms sensitivity. The maximum flow rate was obtained at a 50 μm thickness of PZT and its value was 3.01E-30 m3/s and the maximum displacement of the diaphragm was 1.3962 μm at 40 V and 5 Hz. Thus, the frequency and net flow rate showed an inverse correlation.