What Can Engineers Learn from Nature?

Ed Brown, SAE Media Group

A number of the engineers I’ve interviewed have taken their inspirations from nature. As one said to me, nature has been evolving and perfecting its designs over thousands of years — we should take advantage of that.

So, I decided to look at a few examples of recent research projects to see how well this idea can work in practice.

It Works…

The first project I looked at was done by researchers at McMaster University who have achieved very promising results by mimicking nature. They noticed that lotus leaves sit on water but stay dry. Their research showed that nanoscopic structures on the leaves trap air bubbles, which repel the water. So, they created a flexible plastic wrap with nanoscale “towers” to mimic the lotus leaves’ structure. It repels water, blood, mucus, and all the bacteria and viruses that might be contained in them. “It can be used on high-touch surfaces in hospitals, public transport, and schools. And also, to develop new food packaging, as well as antimicrobial gloves or other personal protective equipment,” said researcher Leyla Soleymani.

Next, I thought that since it’s common for robots to mimic humans, I should check out some robot research. Sure enough, a team of engineers from the University of Singapore used a human hand as inspiration for a robotic three-fingered end-effector. They demonstrated that it can safely interact with delicate items of various shapes, sizes, and stiffness, just like the human hand.

…But it’s Not Always the Best

A quite non-human type of hand, however, was developed by a team from North Carolina State University. They were inspired, not by nature, but rather by kirigami, the Japanese art of cutting and folding paper. Their end-effector can handle delicate objects — for example a raw egg yolk and a human hair — that a human cannot.

Use Nature as a Teacher but Do It One Better

Engineers at the University of California Santa Barbara used nature in their work but went beyond simply mimicking it. They wanted to develop a robot that could navigate its environment by jumping. Mechanical jumpers inspired by nature have been successfully built for years, but they decided to see if they could do better.

They started by comparing biological jumpers to engineered jumpers and made an interesting discovery. Thinking about nature’s design for animal jumpers, they realized that biological systems can only jump with as much energy as they can produce in a single stroke of their muscles.

That led to the idea of engineering a jumper that wouldn’t be limited in the same way. What if they came up with a device that could multiply that energy by storing it in a spring, thus transcending biological limitations. It worked! Their mechanical jumper was able to leap 100 feet into the air — an achievement far surpassing the ability of us poor mortals.

Sometimes it’s Just Flat-Out Wrong

A final study I looked at discovered that mimicking nature could lead to altogether wrong outcomes.

Researchers at the University of Nebraska at Omaha (UNO) wanted to design a way to reduce the energy people spend to walk, which could have applications for therapy received by patients with impaired walking abilities.

Their idea was to attach a waist belt to a pulley to impart a strategically timed pull, helping an individual use less energy for each step while walking on a treadmill. However, the optimal timing of that forward pull was what came as a surprise.

Based on previous literature, the researchers believed they would see the highest energy savings by pulling when the individual is trying to propel forward against the ground. That hypothesis was based on how our biological muscles work during walking.

However, when we walk, there is a short period between steps where one foot is stopping its forward motion while the other is preparing to accelerate to take the next step forward. By varying the timing of the pull, they discovered that this brief window where both feet are on the ground is the best time to apply force to most effectively assist walking.

The Takeaway

Studying nature can be a great source of inspiration for engineering, but don’t assume it’s always the best way.

Do you agree? Share your questions and comments below.

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