Underwater Vehicles
Underwater
Vehicles
Sea Swarm Following the deepwater Horizon accident, around 5 million barrels of oil escaped into the water. Up to 800 skimmers were deployed to remove the water from the surface, but because of challenges of operation and scalability, they were only able to remove 3%. This prompted workers at the Massachusetts Institute of Technology to propose Seaswarm a new system for ocean-skimming and oil removal. At its heart is a nanofabric that selectively absorbs large quantities of hydrophobic liquids like oil without collecting water. The nanomaterial, patented at MIT, can absorb up to 20 times its weight in oil By heating the nanofabric, the oil can be removed and the fabric re-used. Each Seaswarm robot is comprised of a head, which is covered by a layer of photovoltaic cells, and a nanowire covered conveyor belt. This flexible conveyor belt softly rolls over the ocean’s surface, absorbing oil while deflecting water. The photovoltaic cells generate enough electricity to keep the fleet moving for several weeks and provide the energy to propel the vehicles forward. As the head moves through the water the conveyor belt constantly rotates and sucks up pollution. The nanowire-covered belt is then compressed to remove the oil. As the clean part of the belt comes out of the head it immediately begins absorbing oil, making the collection process seamless and efficient.
Seaswarm Prototype
This process is more streamlined than current ocean-skimming technologies because the robots can operate autonomously and don’t need to return to the shore for constant maintenance. Seaswarm is intended to work as a fleet, or “swarm” of vehicles, which communicate their location through GPS and WiFi in order to create an organized system for collection that can work continuously without human support. Because they are smaller than commercial skimmers attached to large fishing vessels, they are able to navigate hard to reach places like estuaries and coast lines. Seaswarm works by detecting the edge of a spill and moving inward until it has removed the oil from a single site before joining other vehicles that are still cleaning. Oil is “digested” locally so that Seaswarm does not need to make repeated trips back to shore, which would dramatically slow collection time. As the vehicles work in unison they can cover large areas and by communicating with each other and researchers on land, they can coordinate their collection efforts. Measuring just 16 feet long by seven feet wide, the fleet can access hard to reach places like coastlines and estuaries. The first Seaswarm prototype was tested in the Charles River in midAugust 2010. The vehicle’s flexible conveyor belt easily adapted to surface waves and successfully propelled itself through the water.
UT2 November 2010
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Seaswarm in development