Researchers in Singapore have built an underwater robot that looks and swims like a manta ray, using only single motors and flexible fins to propel it through water in a manner uncannily like its biological cousin. It's not the first of its kind - academics have spent years trying to mimic the wing-like movements of rays' pectoral fins - but Chew Chee Meng of the National University of Singapore says it's the first to use single motors for each fin and rely on the interplay of fluid and fin. One of nature's most efficient and graceful swimmers, manta rays have long fascinated scientists with a unique propulsion method to cruise through even turbulent seas, flapping their pectoral fins effortlessly to drive water backwards. The MandaDroid is designed after a juvenile manta ray. It measures 35 centimetres (13.8 inches) long, 63 centimetres wide (25 inches), and weighs just .7 kilograms (1.5 lbs).

It's not the first of its kind - academics have spent years trying to mimic the wing-like movements of rays' pectoral fins - but Chew Chee Meng of the National University of Singapore says it's the first to use single motors for each fin and rely on the interplay of fluid and fin.