Just imagine how much of the environment you could save with these Blu-rays of Avatar… and you won’t even have to watch the Pocahontas rip-off. [Image credit: Flickr user Simon Owen]
Scientists are always looking for new ways to improve the efficiency of solar panels, but a group of researchers at Northwestern University is surely the first to find inspiration inside a media cabinet.
The team’s discovery that the tiny grooves in Blu-ray discs absorb light much more efficiently than conventional solar panels was published by Nature Communications in November.
The reason the discs are so efficient is that they’re inscribed with quasi-random nanostructures, which are very small grooves arranged in semi-random patterns. The grooves are designed to increase a disc’s storage capacity, but the Northwestern researchers found the groove patterns can also be adapted to become supreme solar absorbers.
Patterns that either repeat regularly or are completely random don’t trap light well, and the quasi-random structures that trap light the best are usually too expensive to manufacture. But the Blu-ray discs provide a “close-to-optimized” model for light absorption at a cheap price, according to the Northwestern team, which was led by engineers Cheng Sun and Jiaxing Huang.
The researchers used a Blu-ray of a Jackie Chan movie, Police Story 3: Super Cop (with a 7.3 out of 10 average rating on Rotten Tomatoes – not bad) to make a mold that they then used to produce a solar cell with the same micro-groove pattern as the disc. The panel with the CD’s pattern absorbed 21.8 percent more light than a solar panel without a pattern.
The paper noted that “the new insight opens up promising areas, where repurposing of a low-cost consumer product leads to much higher-end, value-added applications.”
Finally, a use for the movies you embarrassingly bought on impulse because it was so cheap. Just think of how many solar panels you could make from the contents of a Walmart bargain bin!