New, tiny manta ray robots could one day hunt lakes for pollution

6 Apr 2017

The graceful manta ray that this new robot is based on. Image: Rich Carey/Shutterstock

Researchers have developed a new, tiny manta ray robot that could one day roam lakes in the hunt for pollution.

The field of soft robotics can sometimes produce almost alien-like creations, resembling some of nature’s strangest and most fascinating creatures.

Last month, for example, a team from MIT revealed a new soft robot based on the jaw of the Nereis virens marine worm. The creature’s jaw is mostly made of organic matter, similar in consistency to gelatine, but has the same strength as human dentine.

No motor required

Once again, researchers are looking to our oceans for answers in a bid to make better, faster and more agile aquatic robots.

According to a new paper published to Science Advances, a team from Zhejiang University in China has developed a tiny manta ray robot that can gracefully glide through water.

While the soft body, fin and parts were relatively easy to develop, this latest breakthrough was significant because the researchers were able to solve the problem of creating an efficient power source.

Manta ray robot

The soft robot inspired by the manta ray. Image: Li et al

To do this, the team eliminated the need for a motor and used the water surrounding it as a ground electrode to propel itself forward.

The soft material around the robot is made from hydrogel that reacts to a small electrical current, resulting in the flapping of its fins in a similar fashion to an actual manta ray.

The addition of a tail allows it to steer itself in any direction, moving with the help of an electromagnet.

At just under 10cm in length, the robot can swim at a speed of 3cm per second and will last for as long as three hours on a single charge.

Possible spy drone

It is also strong enough to carry a small camera or sensor. This makes it twice as capable as – and faster than – any similar robots previously developed.

If necessary, the robot could even be powered for longer via a tethered connection, and can handle both hot and cold water.

Researchers suggest that the manta ray robots could monitor water quality in lakes, streams or oceans, possibly detecting heightened levels of pollution.

They could also be used in the search for survivors in the event of a water-related incident, or even as a military spy drone, as they can be built with transparent material to provide excellent camouflage.

Colm Gorey was a senior journalist with Silicon Republic