Advances in Technologies of Piezoelectric Pumping with Valves

Piezoelectric pump faces unprecedented challenges when higher expectation and requirements need to be met in their applications mainly to medical treatment, hygiene and public health, and preventive healthcare. Specifically, the piezoelectric pump with valve has the disadvantages of complex structure, high duty cycle of valves, and valve movement lagged behind piezoelectric ceramics oscillation. In an attempt to inhibit its shortcomings, some researchers presented novel concepts for structural design of piezoelectric pump with valve, which could become a new research focus. Among them, the investigation into various soft valves, represented by soft structure valves made of rigid materials and soft material valves made of flexible materials, has been fruitful in recent years. The integrated design of both material and structure can tackle the problems encountered in the study of piezoelectric pump with valve, thus simplifying the pump structure, reducing the duty-cycle of valves, and improving the lag- ging of valve motion. In addition, new inventions of pump structure have sprung up, such as the pumps containing a single-chamber with double-drive, single-chamber with single-drive in series and single-chamber with single-drive in parallel, as well as the mixed-chamber in series and parallel. After surveying the recent progresses made by dominant academia in the development of piezoelectric pump encompassing valve, with a particular emphasis on structure design of both valve and pump body, we also summarize and identify the future research directions.