The cutting edgeRobot sub recharger

Autonomous underwater vehicles (AUVs) are becoming more popular and sophisticated, and are revolutionizing oceanography. They are also playing a larger role in securing ports and infrastructure facilities located near bodies of water. Powering them is problematic, though. Having the robots feed on plankton is one idea, but simply having them recharge underwater without human input would cut the costs of attending boats and crew, and is a more near-term solution. In principle, a docking AUV could recharge its batteries, download the data it has collected during its mission, and upload new mission plans all at once. Conventional electrical contacts, however, have many problems underwater, says a team funded by the Office of Naval Research in Arlington, Virginia. Saltwater can corrode metal contacts, and growths of algae and other marine life can appear on exposed metal in just ten days. So Robert Coulson and colleagues have designed a wireless energy transfer system — a strong magnetic field made by the docking station induces a current in a part of the AUV to charge its batteries. The dock could be installed in a remote area costly to reach by ship.

Read the full wireless underwater robot recharger patent application.