微型压电泵中腔高对气泡滞留的影响规律

Influence of pump-chamber height on bubble retention in piezoelectric micro-pump

气泡滞留会严重地损害微型压电泵的输出性能,因此减少气泡滞留将有效地提高压电泵系统的稳定性和可靠性。泵腔作为气泡滞留的主要区域,同时是决定输出性能的重要元素,所以改变腔高将对气泡滞留产生重要的影响。本文从气泡压力降和输出压力两个方面建立数学模型,以此分析腔高对气泡滞留的影响规律,最后通过气泡滞留实验进行验证。实验结果表明,腔高为0.15mm时,压电泵具有优良的输出性能和排气泡能力,在进入120个0.02mL气泡后,压电泵仍具有稳定的输出压力(8.1kPa)和输出流量(4.2mL/min);腔高为0.05mm和0.20mm时,压电泵在进入一个气泡后即丧失了工作能力,排气泡能力差,而腔高为0mm和0.10mm时,压电泵分别进入47和70个气泡后丧失了工作能力。实验表明选取合理的腔高可以有效地减少气泡的滞留。

Since bubble retention may cause serious damage to output performance of piezoelectric micro-pump,properly reducing bubble retention can effectively improve stability and reliability of the piezoelectric pump system.Pump chamber is the main area for bubble retention and an important element determining the output performance,so change in the chamber height will have significant influence on bubble retention.In this paper,a mathematic model was established based on bubble pressure drop and output pressure to analyze the influence rules of chamber height on bubble retention,and then a bubble retention test was carried out verify the results.It indicates that when the chamber is 0.15 mm high,the piezoelectric pump has excellent output performance and ability to exclude bubbles,and after 120 0.02 mL bubbles entering the chamber,the pump still has a stable output pressure（8.1kPa）and output flow（4.2mL/min）;when the chamber height is 0.05 mm and 0.20 mm,the piezoelectric pump is unable to work after a bubble enters,with a weak ability of excluding bubbles;when the chamber height is 0mm and 0.10 mm,the piezoelectric pump is unable to work respectively after 47 and 70 bubbles enter.The results show that reasonable chamber height can effectively reduce bubble retention.