A communications system and method of use thereof in which communication system includes a substrate and an array of pumps of mounted on the substrate. The array of pumps are operable for operating at a first frequency to produce sound waves at a second frequency. The first frequency is higher than the second frequency. IN some embodiments, the pumps in the array of pumps can include a first cavity having a first inlet and a first outlet, a first plurality of electrically conductive traces located within the first cavity, and a continuous sheet of electrically conductive material spaced apart from and in close proximity to the first plurality of electrically conductive traces. The first plurality of electrically conductive traces are operable for creating a first time-varying deflection in the electrically conductive material. The first time-varying deflection moves in the first cavity from the first inlet to the first outlet.