Maritime Power Harvesting Piezo-Rubber Transducers for Autonomous In-water Sensors

The objective of this Navy Phase II SBIR program is to demonstrate the feasibility of using Piezoelectric Metal RubberTM (PMR) material for the harvesting of energy and the charging of batteries used by electrically-powered transponder systems underwater. PMR is an elastic piezoelectric material that produces electrical charge when mechanically strained. Cables containing PMR material can be held in tension underwater and periodically strained due to resonant vortex shedding induced by water flow. Charges generated by the PMR material can be collected and used to charge a local battery. The total energy stored can be scaled by increasing or decreasing the total number of segments, either in a single cable or in a cable array. This approach is potentially attractive for a number of Navy systems that require different power levels for long-term unattended operation. During Phase I, NanoSonic demonstrated the fabrication of initial PMR material, measured its piezoelectric properties, and analytically designed an underwater energy harvesting system approach building on PMR material and its response. During the Phase II program, NanoSonic would fabricate materials with optimized properties, and design, build and evaluate the performance of prototype energy harvesting systems through laboratory, water flow tank, and fresh water and ocean tests.