A miniature piezomembrane hydraulic pump with decreasing chambers in succession

A miniature piezomembrane hydraulic pump with decreasing chambers in succession (PHPDCS) is presented. The number of chambers in PHPDCS decreases successively in two serial stages. The first stage consists of two chambers in parallel while the second stage consists of only one chamber. The proposed PHPDCS has the comprehensive advantages of serial and parallel connection of multi-chamber and has a high energy conversion efficiency. The prototype of PHPDCS is designed and manufactured. The output performance of PHPDCS under different external loads is investigated by experiments. Experimental results indicate that the optimum flow rate of the proposed PHPDCS is obtained when phase difference between two serial stages is 180°. The output performance of PHPDCS is superior to that of traditional piezoelectric pumps with two chambers in serial (PPCS). At 50 Hz, the maximum flow rate of PHPDCS under external load of 5 kPa is more than twice as high as that of PPCS. Under the external load of 10 kPa, the maximum flow rate of PHPDCS reaches 6.87 mL/min, whereas PPCS has no flow rate output.