Ocean Wave Harvesting by Piezoelectric Coupled Buoy

The Challenge Therecent development of low powered devices and appliances, such asLight-emitting diodes (LEDs), low cost wireless sensors and wireless accesspoints, has increased the interest in self-power techniques such as theharvesting of energy from ambient vibration. Among the available mechanic-to-electric energy conversion mechanisms,such as electromagnetic, electrostatic and piezoelectric transductions, theenergy density of the piezoelectric transduction is three times higher thanelectrostatic and electromagnetic transductions.Windand waves are two obvious sources of ambient energy.  For various reasons, of the two, wave energyis a more appropriate choice and in fact it has been shown that that energyharvesting from ocean waves by piezoelectric materials is effective and is ableto generate sufficient electric power for small electric appliances.  However, most of piezoelectric energyharvesting structures in current studies are designed to be fixed on the seabed, and hence are mostly applicable to shallow ocean and costly. It is obviousthat the amount of the ocean wave energy in the intermediate and deep oceanwith larger wave heights is much larger than the one in the shallow-water. Therefore, aneed exists for a more efficient and economical energy harvesting from intermediateand deep oceans.

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