Looking deeper into biomimicry: how nature inspires design

Effective design takes cues from the animal kingdom

One of the most important aspects of design is the notion of iteration—meaning how we shift, refine, and improve upon our products or process—so it makes complete sense that we look to the animal kingdom for inspiration because of its millennia of experience in evolutionary trial and error. We can see the evidence in the fossil record, and surrounding us is the secret to survival and success.

Biomimicry, also spelled biomimickry, is the act of finding solutions to human challenges by emulating patterns and strategies found in nature. And if you look closely, you can see it everywhere: architecture, energy generation, agriculture, and medicine among others.

Let’s talk about one of the most talked about examples today in the realm of transportation. You might think that you know this story, but there are some details that people often don’t talk about. We’ll get there — hold on.

When the Bullet Train Meets a Silent Hunter

This story starts with Eiji Nakatsu, a Japanese engineer with West Japan Railway Company, who was working on the new 500-Series Shinkansen. Colloquially known in English as the bullet train, it travelled at over 200 miles per hour (320 km per hour), which was creating a problem — not with heating or stability, but with noise. As one of these trains would rocket into a narrow tunnel, it would often create a loud shock wave on its way out: BOOM!

This is a high-speed pantograph that is on the E5-Series Shinkansen — photo from http://locomotive.wikia.com/wiki/Pantograph

It turns out that a majority of this noise was caused when air at speed hit structures on the train called pantographs, or collection devices mounted on the roof that receive electricity from overhead wires and were necessary to supply power.

The team was stuck on how to solve this problem until Nakatsu saw a notice for a lecture by Seiichi Yajima, an aircraft design engineer and member of the Wild Bird Society of Japan. You see, Nakatsu wasn’t just an engineer, he was also an avid birdwatcher. And at this talk, he learned how much of both past and present aircraft technology is based on the studies of the functions and structures of birds.

Nakatsu learned that owls are some of the most silent hunters because their wings’ leading edge, or primary feathers, are covered in small structures — hooks and bows—that protrude from the outer rim, chopping up the flowing air up into smaller micro-turbulences. No other birds have these feathers, also called “serration feathers,” and these are what make owls whisper-quiet in flight.

Inspired by the owl, the engineering team at JR West — over the course of several years — created a series of serrations on the main part of the pantograph, succeeding in reducing noise enough to meet the strict environmental standard in Japan. However, while the “boom” was quieter, it was still there, and they needed to do more.

And Now, the Second Bird

Eisvogel Alcedo atthis Ed Merritt Photographer: Gisela Delpho / Picture Press — photo from https://flic.kr/p/9FW1wg

Enter, the kingfisher, who is noted for, among other things, their spectacular ability to dive into water to catch fish, crustaceans, amphibians, and reptiles—especially impressive because they do it with no or very little splash.

When the bird makes the transition from flying through the air (a low-resistance medium) to diving into the water (a high-resistance medium), its long beak increases in diameter gradually from the tip to the back as it plunges to catch its next meal.

Nakatsu and his team measured the pressure waves that arose when shooting bullets of various shapes into a kingfisher beak shaped pipe, confirmed their observations, and then ran a series of tunnel simulations with trains outfitted with this shape. Data analysis showed that the ideal shape for this series of Shinkansen is identical to that of a kingfisher’s beak.

This is the end car of the first delivered set of 500-Series Shinkansen as seen at the Kyoto Railway Museum in May 2016 by Rsa — photo from https://commons.wikimedia.org/w/index.php?curid=48640681

Next, they fitted the front of the train with a design similar to the kingfisher’s beak. And just like that, the tunnel booms were gone.

The 500-Series entered service in 1997. Trains were quieter, were 10 percent faster, consumed 15 percent less electricity, and were reported by customers to offer a more comfortable ride — all thanks to biomimicry.

While N700 series trains have since replaced 300, 500, and 700 series sets on the Nozomi services, running on the Tokaido/Sanyo lines in Japan, the 500-Series trains are still running on the Kodama line between Shin-Osaka and Hakata. And still as quiet as ever.

In a few weeks, I’ll look at another popular example of biomimicry that isn’t actually what it seems. A hint in two words: biomimetic sharkskin.

Thanks for reading.