# A High-Performance Piezoelectric Micropump with Multi-Chamber in Series
## 6 Conclusions  
Based on the single-chamber micropump, a series of multi-chamber series piezoelectric micropumps is proposed. After analyzing the working principle, the piezoelectric micropump prototypes with different parameters were fabricated for testing, and finally, the experimental conclusions were drawn. The specific conclusions are as follows:  
1. We conclude that the valve opening and pump chamber height will affect the output performance of piezoelectric micropump. Too small of a valve opening is detrimental to the opening of the valve, affecting the flow efficiency of the fluid, and too of a large valve opening is not conducive to the rebound of the valve, which will cause fluid leakage and affect the output performance of the micropump. Proper valve opening will improve the rebound speed of the valve and prevent the valve from failing due to over-opening. Too small of a pump chamber height will hinder the movement of the valve and too large of a pump chamber height will increase dead volume, thus affecting the performance of the piezoelectric micropump. After a great deal of experimental research, this paper found that when the valve opening is 0.4 mm and the pump chamber height is 0.1 mm, the comprehensive output performance of the piezoelectric micropump is the best. 2. The piezoelectric micropump in this study can achieve high output performance under the condition of small size, and the performance of the multi-chamber micropump is better than that of the single-chamber micropump. The double-chamber series micropump has a maximum output flow rate at 120 Hz and a maximum output pressure at 100 Hz, while the four-chamber series micropump has a maximum output flow rate at 450 Hz and a maximum output pressure at 550 Hz. It is evident that the best frequency for the output flow rate and output pressure is different, so the frequency with the best comprehensive performance can be selected to drive the piezoelectric micropump. The frequency of the output flow rate and pressure of the four-chamber series micropump is higher than that of the double-chamber series piezoelectric micropump. This is because the response characteristics of the piezoelectric micropump in resonance state change, which affects the outflow efficiency of the micropump inlet and outlet. 3. Under the same voltage, the output flow rate of the four-chamber micropump is about 1.69 times that of the double-chamber micropump and 2.97 times that of the single-chamber micropump, and its output pressure is about 2.39 times that of the double-chamber micropump and 4.5 times the single-chamber micropump. The output flow rate of the double-chamber micropump is about 1.73 times that of the \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Authors** & **Q (mL/min)** & **P (kPa)** & **Voltage** & **Footprint** \\ \hline [PERSON] [16] & 469.2 & 16.1 & 150 V & \(170\times 50\times 20\) mm\({}^{3}\) \\ [PERSON] [20] & 1678.2 & 2.18 & 240 V & \(50\times 50\times 16\) mm\({}^{3}\) \\ [PERSON] [21] & 318 & 4.05 & 130 V & \(54\times 49\times 15\) mm\({}^{3}\) \\ [PERSON] [22] & 1660 & 85 & 300 V & \(30\times 37\times 72.5\) mm\({}^{3}\) \\ [PERSON] [18] & 186 & 125 & 2 MVm\({}^{-1}\) & \(45\times 10^{3}\) mm\({}^{3}\) \\ Present study & 110 & 142 & 170 V & \(53.8\times 22\times 5\) mm\({}^{3}\) \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Current situation of piezoelectric micropumps at home and abroad. single-chamber micropump, and the output pressure is about 1.88 times that of the single-chamber micropump. This shows that the multi-chamber series piezoelectric micropump can effectively improve the output performance of the piezoelectric micropump, especially for the output pressure of the piezoelectric micropump. That is, the multi-chamber series micropump can obtain higher output performance under lower operating conditions, which is more conducive to practical applications. Conceptualization, X.L. ([PERSON]); methodology, X.L. ([PERSON]); software, X.L. ([PERSON]); validation, X.L. ([PERSON]), X.L. ([PERSON]), M.W.