This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American
It looks like a solar-powered treadmill, but researchers at the Massachusetts Institute of Technology (M.I.T.) say they have created a flat, conveyor belt–like device that could clean up oil slicks far more efficiently than anything used at the Deepwater Horizon site. They key is a nanoparticle-infused, water-repelling mesh coating a conveyor belt. As important is the device's ability to work autonomously as part of a larger team of devices, which M.I.T. calls a Seaswarm.
Members of M.I.T.'s Senseable City Lab, which made a name for itself a year ago through its Trash Track program for keeping tabs on discarded electronics, will present their Seaswarm research—as well as a video demonstrating a prototype in action—Saturday at Italy's Venice Biennale international art, music and architecture festival. Venice Biennale's theme this year is how nanotechnology will change the way people live in 2050.
Here's how a Seaswarm oil cleanup effort might work: Each five- by two-meter device within the Seaswarm uses its conveyor belt to skim oil out of the water as well as propel itself forward. With GPS and oil-detecting sensors to guide them, the devices could position themselves to attack oil slicks like a swarm of hungry caterpillars on a leaf.
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If you run your fingers over the nanomaterial, it feels smooth, says Assaf Biderman, associate director of the Senseable City Lab. "Imagine a sponge where the pores are very small." The material isn't specific to oil absorption, so it could potentially be used to clean other types of chemicals out of water as well.
The reusable nanoparticle mesh coating can absorb up to 20 times its own weight in oil, M.I.T. estimates. The device cleans its conveyor belt by heating up the mesh to burn off the oil. Each device is powered by two square meters of solar panels and is designed to run on just 100 watts. Because the device is flat it should adhere to the water's surface and move with the waves to avoid capsizing, Biderman says.
Cleanup efforts have deployed more than 800 conventional skimmers to the Gulf of Mexico this summer to contain BP's oil spill, yet they could not collect more than 3 percent of the subsurface oil, according to M.I.T. These skimmers use belts, rotating discs and ropes to mechanically separate oil from water.
A fleet of 5,000 Seaswarm devices could clean a spill the size of the one at the Deepwater site in one month, M.I.T. researchers estimate. They aim to prove this supposition by entering the Seaswarm design into the X PRIZE's $1 million oil-cleanup competition, which will award the team that can most efficiently collect surface oil with the highest recovery rate.
The National Oceanic and Atmospheric Administration (NOAA) estimated earlier this month that 4.9 million barrels spilled into the Gulf of Mexico after the April 20 explosion at BP's Macondo well. Government scientists say about 50 percent of the spilled oil has been captured, evaporated, burned or skimmed, and another 25 percent has naturally or chemically dispersed, although other scientists have disputed these claims, saying that the government has underestimated how much oil remains at large.
