**Abstract**

Fluidic driving device plays an important role in the delivery and distribution of minute amount of the liquid in the micro-fluidic system. Due to the unique advantages of simple structure, short response time, and low power consumption, piezoelectric actuation was employed to implement the microfluidic transportation. A piezoelectrically driven microfluidic device, piezoelectric pump, was developed and widely applied in many fields in last three decades. As a kind of displacement pump, piezoelectric pumps is able to realize accurate transportation of the liquid because of per stroke of output fluid is equal to the volumetric change of pumping chamber. And the output flow rate and pressure is easily to be controlled through adjusting the driving voltage or frequency. In this chapter, the design, structure, working principle and the characterisation of piezoelectric pumps with single chamber and multiple chambers are introduced.

**Keywords:** piezoelectric actuator, microfluidic technology, micropump, single chamber, multiple chamber, flow rate, pressure

## **1. Introduction**

Microfluidic modules have broad application prospects in chemical analysis, biomaterial analysis, fuel cell, and medical [1, 2]. In the microfluidic system, the fluid pump is the core to realize small and accurate liquid delivery and distribution [3, 4]. Therefore, a variety kinds of micropumps have been developed [5–8]. Because of its simple structure, high energy density and simple control, piezoelectric pump has potential application prospects in drug delivery, chemical analysis, micro refrigeration system and micro spacecraft propulsion [9–11].

According to the driving components, piezoelectric pump can be divided into piezoelectric stack pump and piezoelectric diaphragm pump. The piezoelectric diaphragm pump owns superiorities of small volume and low power consumption. This chapter will take the piezoelectric diaphragm pump as the example to introduce the piezoelectric microfluidic technology.
