Abstract: A piezoelectrically driven fluid pump includes a chamber having two opposite sidewalls formed by flexible membranes, and an inlet and an outlet each regulated by a valve. Separate piezo elements are fixed to each of the membranes, to flex the membranes and increase or reduce the chamber volume and thereby draw fluid into the chamber or expel fluid from the chamber. The valves are each formed by two adjacent piezo elements that are supported or flexibly joined together at two opposite ends. When actuated, the valve piezo elements flex outward between the two opposite ends, opening the valve to form an aperture between the two piezo elements. In another embodiment, a fluid pump includes a chamber having one flexible membrane sidewall. A valve-regulated inlet or outlet aperture through the membrane communicates with the pump chamber. A ring-shaped piezo centered around the aperture, on the membrane, flexes the membrane.