Engineers are trying to emulate the effortless but powerful swimming motions of stingrays and manta rays by creating their own ray-like machine modeled on nature. “They (rays) are wonderful examples of optimal engineering by nature,” said Hilary Bart-Smith, associate professor of mechanical and aerospace engineering in the University of Virginia's School of Engineering and Applied Science. 

Bart-Smith and her colleagues at three other universities are designing an “autonomous underwater vehicle” that someday may surpass what nature has provided as a model. The vehicle has potential commercial and military applications, and could be used for undersea exploration and scientific research. They say stingrays and manta rays are fast, maneuverable, energy-efficient, can cruise bird-like for long distances in the deep ocean and rest on the sea bottom. 

The engineers are trying to mimic the manta ray

The engineers are trying to mimic the manta ray

Sometimes called “bio-mimicry” — the attempt to copy nature — Bart-Smith calls her work “bio-inspired,” according to a Virginia statement. “We are studying a creature to understand how it is able to swim so beautifully, and we are hoping to improve upon it,” she said. “We are learning from nature, but we also are innovating; trying to move beyond emulation.” Bart-Smith's team, which includes researchers at Virginia, Princeton University, the University of California-Los Angeles and West Chester University, are modeling their mechanical ray on the cow-nosed ray and common to the western Atlantic and Chesapeake Bay. 

Biology has solved the problem of locomotion with these animals. So we have to understand the mechanisms if we are going to not only copy how the animal swims, but possibly even to improve upon it,” Bart-Smith said. Her team is trying to achieve optimal silent propulsion with a minimum input of energy.