Buoys bobbing up and down in the ocean could one day provide a cheap, clean source of electricity for households across the US. Ocean energy is becoming a hot research area recently, and the buoys have the advantage of being simple, inexpensive, and environmentally benign.
Researchers from the Stanford Research Institute International in California have recently shown that electroactive polymer artificial muscles can produce electricity as they bob up and down attached to the buoys.
The artificial muscles consist of rubber sheets sandwiched between two oppositely charged electrodes. The scientists rolled these sheets into a cylindrical shape, fixed a weight to one end, and enclosed it in a capsule inside a buoy. When a wave makes the buoy bob up and down, the rubber stretches and relaxes. This motion changes the distance between the two electrodes, which generates electricity.
Currently, the buoy design can provide just enough power for light bulbs. Every 0.8-meter wave creates about 20 watts of electricity, but the researchers predict they can improve the design by several orders of magnitude. With hundreds of thousands of buoys floating in the ocean, such a method could provide up to an estimated 10% of the total US energy needs, with no negative environmental effects.
via: New Scientist Tech