This article provides an extensive outlook of different types of piezoelectric actuated micro-pumps published in the literature recently. We start by reminding the reader about the conventional operating parameters used to quantify the capabilities of these devices. After this introductory stage, we describe and classify the most prominent micro-pump's geometries found with piezoelectric actuation. At this point we identify the parameters given previously for each pump in order to establish a subsequent discussion in which the trends of different families are compared. Specific attention is given to the particularities of each case namely: flow rates and backpressures.