Abstract: A method for harvesting energy for wireless fluid stream sensors is provided that includes locating a wireless fluid stream sensor in a fluid stream. The wireless fluid stream sensor includes a flexible membrane and a rod. Energy is harvested based on strain induced in the flexible membrane due to movement of the rod. The wireless fluid stream sensor may be powered with the harvested energy. The energy may be harvested with piezoelectric elements that are coupled to the flexible membrane or with piezoelectric elements or other type of energy-harvesting components that are located remotely from the wireless fluid stream sensor.