Soon, underwater robots inspired by Amazon electric fish

Scientists are in the process of developing underwater robots that have been inspired by Amazon electric fish.

The weakly electric black ghost knifefish of the Amazon basin has inspired Northwestern University's Malcolm MacIver and an interdisciplinary team of researchers to develop agile fish robots that could lead to a vast improvement in underwater vehicles used to study fragile coral reefs, repair damaged deep-sea oil rigs or investigate sunken ships.

MacIver, a robotics expert who has studied the black ghost knifefish for two decades, said that their technology for working in water is not very advanced.

He said that the current underwater vehicles are large and lack agility, which means that working close to living or manmade structures is nearly impossible, asserting that they've taken lessons learned from the knifefish about movement and non-visual sensing and developed new technologies that should improve underwater vehicles.

The black ghost knifefish hunts at night in the murky rivers of the Amazon basin using closely integrated sensing and movement systems. It has the unique ability to sense with a self-generated weak electric field around its entire body (electrosense) and to swim in multiple directions. The fish moves both horizontally (forward and backward) as well as vertically using a ribbon-like fin on the underside of its body.

MacIver and colleagues in Northwestern's Neuroscience and Robotics Lab have developed more than half a dozen robots based on the weakly electric knifefish. A major motivation for creating the robotic models of the knifefish is to generate a better understanding of how the nervous system combines the acquisition of information with movement.