Miniature pumps are the key components in microfluidic systems. They are widely used in many applications such as lab-on-chip, micro-total analysis systems and micro-dosage systems. The most important component in a miniature pump is the actuating mechanism because it is directly related to factors such as flow rate, driving source and cost. Currently, the most common driving mechanisms are piezoelectric, electromagnetic, thermo-pneumatic and electrostatic. They all have their own advantages and disadvantages. The main advantages of using ionic polymer metal composites (IPMCs) as the actuating mechanisms are that they have large displacements at low voltages, which will correspond to large flow rates, making them good for long lifespans in portable and embedded applications. Here, we demonstrate a miniature pump actuated by an IPMC controlled using a proportional-integral-derivative controller with iterative feedback tuning. This chapter also shows the design, modelling and simulation of a valveless pump using a diffuser/nozzle structure.