The US Navy is interested in developing underwater robots to be used in a wide spectrum of scenarios, from inspection to surveillance through exploration and rescue.
As with aerial drones, however, their aquatic "cousins" also suffer from the same autonomy limits due to battery life.
There is a solution on the horizon, perhaps not very elegant but effective: equip these robots with biological fuel cells capable of powering themselves with organic waste from fish deposited on the seabed.
Do I have to be more explicit? Underwater robots eating fish poop to feed their batteries.
The “material” is evidently available in quantity, ready to be used. to be converted in energy. A research team led by Meriah Arias-Thode at the Naval Information Warfare Center Pacific in San Diego has already started experiments.
Currently, 3 different biofuel cells are being tested that can power several small sensors, like them able to to measure the acidity of the water. The current sensors used have an autonomy of a few weeks: with this battery they can reach eight months.
Among the solutions being studied for the practical applications of these batteries is the use of underwater drones of all kinds and the establishment of 'charging points' directly on the seabed: the density of biological batteries would mean that these can to be permanently charged (like a sort of power bank) and to constitute meeting points for robots that have energy shortage.
