Our Blue Backyard: Inventions inspired by nature

Auckland researchers have taken inspiration from the biology of sharks and other sea creatures to create new innovations. Photo / Iain Anderson

In the second of a five-part series looking at Auckland University's research in the region's blue backyard, science reporter Jamie Morton talks to researchers who are creating innovations inspired by nature.

A sleek, human-driven submarine and a cutting-edge underwater sensing system are among the impressive innovations of a team of Auckland University engineers.

What's inspired their pioneering designs hasn't come from the world of technology, but from one that has existed far longer than we have: the marine environment.

The university-based Auckland Bioengineering Institute (ABI) is collaborating with researchers from the Institute of Marine Science and School of Biological Sciences to apply in the lab what lessons they can learn from nature.

Leonardo De Vinci "had it pretty much covered" , the marine institute's Professor John Montgomery said, when the great innovator said: "The genius of man may make various inventions ... but they will never be more beautiful, more economical, or more direct than nature's, since in her inventions nothing is wanting and nothing is superfluous."

While the pace of change hadn't been fast in nature, the timescale on which change had happened had been immense, and within oceans, natural selection had been at work for millions of years.

"This long sequence of experiments has produced both beautiful and bizarre examples of functional design, which have a real potential to inspire new technology," Montgomery said.

This concept was encapsulated by the field of biomimetics and formed the topic of a new CRC Press book, Ocean Innovation: Biomimetics Beneath the Waves, just published by Montgomery and his ABI collaborator Associate Professor Iain Anderson.

Marine science had long involved working with other disciplines - physics was a big driving force when Auckland's Leigh Laboratory was established in the post-war era - but the rise of biomimetics had come only recently.

Reviews of the state-of-the-art in biomimetics showed this research area expanded rapidly from less than 100 papers per year in the 1990s to several thousand papers per year in the first decade of this century, Montgomery said.

These reviews also highlighted the impact this research was having in numerous themes, spanning from robotic and computer science to bioengineering.

The Auckland University collaboration was also relatively new, and had been sparked by Anderson's joint passion for engineering and recreational diving and photography.

Anderson's interest in electroactive polymers (EAPs) has already led to significant innovations in sensing and actuation using soft materials.

Scientists test out the "Taniwha" human-powered submarine, which was inspired by nature. Photo / Iain Anderson

"As some of our technologies for machines and robots shift from more traditional hard materials to softer more biological-like materials, then the use of biologically inspired sensing, actuation and control will become more and more important," Montgomery said.

A stand-out example of the ABI's biomimetics work is the Taniwha, a human-powered submarine that Anderson and his team recently won an international race with.

The researchers want to take the design further by adding fins for steering, braking and feeling; when they're not needed they can be folded out of the way of the water flow.

"We are also exploring the combined use of fins in a flexing fish-like body," Anderson said.

"We know that this can work for humans - it's worked for fish for almost 400 million years."

Another project, led by PhD student Tony Tse, is working toward a means for sensing underwater sound direction that's inspired by the mechanism of the fish's ear.

In a pioneering study, Montgomery has shown that juvenile fish use sound to find a reef on which to settle.

How they do this has been the subject of pioneering NZ based research by Montgomery's team.

"Determining sound direction underwater is extremely challenging because sound moves five times faster in water than in air," Montgomery said.

If our ears were five times further apart, he explained, we'd be much better off at determining sound direction.

Most fish, smaller than us can sense sound direction - something important for finding the direction to the reef and each other.

Scientists test out the "Taniwha" human-powered submarine, which was inspired by nature. Photo / Iain Anderson

"Some make little noises that they use to find each other and they use little rock-like structures, or otoliths, in their hearing mechanism.

"Each otolith more or less stands still while their whole body moves in the sound wave, and Tony is building a device that works on this principle."

A big focus of Montgomery's own work has been the study of sensory systems and brain function in sharks and rays.

"These animals have an exquisitely sensitive electrosensory system that can detect the weak electric fields of their prey," he said.

One of the problems they have to solve is to distinguish between their own electric fields and those of the prey.

"In our work we have shown that this is done by a specific part of the brain that acts like noise-cancelling headphones to cancel electrosensory inputs driven by the animal's own movements."

This part of their brain was called "cerebellum-like", since it shared many similarities with our own cerebellum.

"In fact our work suggests that the cerebellum evolved from these cerebellum-like structures."

Understanding how this part of the brain worked in sharks offered unique insights into the evolution of the cerebellum and its function.

There was the potential to use the same signal processing capabilities applied to acoustic signalling to improve communication for autonomous underwater vehicles.

When it came to such innovation, Montgomery saw New Zealand scientists as "up there with the best".

"But what excites us is the rapid way in which this area is taking off, and that in specific domains - such as ocean innovation - where New Zealand has a clear interest, we should be collectively aiming to be leading participants."