Description:
Abstract
USC researchers have demonstrated vastly improved vibrational-to-electrical energy conversion efficiencies using a large array of small magnets along with a large array of small coils. This design maximizes the magnetic flux change as the coil and magnet arrays move in response to vibrations for an efficiency improvement of several hundred times over the single coil and magnet design. A total of 10.2 milliwatts was harvested from a vibrating 6-gram mass at 100 Hertz. If the design was scaled accordingly for applications involving ocean waves and reducing the resonant frequency to 1 Hertz, 25.6 kW of energy could be produced for an ocean wave with a 0.25 meter amplitude. In this way, the design could be used together with existing ocean energy technologies such as the power buoy and Archimedes wave swing. ?
Benefit
Market Application
Considerable interest has been expressed in the idea of generating electrical energy from mechanical vibrational energy through electromagnetic transduction. With the ubiquity of possible candidates from which to harvest vibrational energy -- such as vehicles, building walls, and bridges -- any method of efficiently converting vibrational energy to electrical energy would prove to be extremely valuable. However, previous designs have primarily been based on a single coil in tandem with a single magnet, and this type of design generates very poor energy conversion efficiencies that make potential large-scale power generation on the order of megawatts to gigawatts completely unfeasible. ?
Publications
Energy harvesters with high electromagnetic conversion efficiency through magnet and coil arrays, IEEE Micro Electro Mechanical Systems, Jan. 2013
Other
Proof-of-concept demonstrated successfully