The Borrowed Nature of Biomimicry

Back in 1989, the engineers of Japan's famous Shinkansen bullet train realized they had a problem. The train was moving so fast that when it went into a tunnel, it basically punched the air out the far end creating little sonic booms. All across Japan, the Shinkansen was rattling buildings and disturbing residents in the neighborhoods it passed through.

“An engineering team was brought in to design a quieter and more efficient train, and they had a secret weapon.”

A.G. Nikatsu, the general manager of the technical development department, was a bird watcher. As he thought about the redesign, Nikatsu took inspiration from elements of his favorite birds, including owl feathers and penguin bellies.

But the bird that inspired the most important element of the redesign was the kingfisher.

Kingfisher's are famous for the elegant way they dive into the water to catch fish. Their uniquely shaped beaks allow them to break the surface of the water with barely a splash. And so Nikatsu and the Shinkansen design team decided to model the nose of their bullet trains off the kingfisher's beak. And it worked. The new Shinkansen trains were quieter and more efficient. That kingfisher redesign is now seen as a classic example of what's known as biomimicry.

The act of looking to the non-human world for solutions to human design challenges. Biomimicry is simply designed that is inspired by nature.

Right, and I have to say that stories about biomimicry are catnip to design journalists like me.

That is Kurt Colestead, our resident design guy.

“Yep, and biomimicry, it's just this really inspiring concept, right?”

With all these fascinating examples, like the invention of Velcro being inspired by someone noticing how birds stuck to his dogs fur and to his jacket while he was out on a walk. Yeah, I mean, I love these stories. We love these stories on the show. We've covered biomimicry a lot over the years because the stories are just very catchy. Like, there is something so seductive about the idea of designers borrowing from nature to solve

a human problem. It's just a very neat, simple, and just compelling narrative. Yeah, for sure. But recently, I've been digging into a bunch of biomimicry stories

and they are not always quite as neat and simple as that bullet train story.

The causality is often quite a bit murkier than the headlines would have you believe.

“And the relationship between nature and human inspiration is often more complicated.”

Yeah, and that actually makes biomimicry sound more interesting to me, not less. Like, I like that idea of a complex story. Way better. Yeah, I agree. Same here. So today we're going to have deeper, go beyond some simple headlines, separate some facts from fiction, and yeah, I go into some more nuanced cases. But to kick things off and ground us in the concept, I want to start with a relatively straightforward,

yet lesser known example of biomimic design. So this story takes place in the early 1800s in London, England, which was not yet that modern city that we know with its sophisticated transit network or really even basic sanitation, but it was already the largest city in the world and the largest port in the world. And when people needed to cross the city's famous tem's river,

near that port, they took the London bridge. But that bridge was notoriously crowded. It was like a choke point for everyday citizens and also commercial traffic, which really burdened people as well as, you know, the city's commerce. And so over time, it became clear that another crossing downstream was desperately needed. Yeah, that makes sense to me because they needed another bridge.

Totally. Except with the geography of the river and the port and the existing bridge, another bridge would have interfered severely with shipping access. So that solution was a non-starter. And the only real alternative was to tunnel under the river. But this is way before the channel to France or even the London Underground. So there was no precedent for tunnels going under active waterways. Tunneling technology at this point was essentially an extension of mining technology,

right? Dealing with solid rock and soil, but not the undersides of rivers. And so they tried to use those surface traditional mining techniques to tunnel under the tem's, but it ended in disaster. And in some cases, the deaths of workers. And experts eventually came to conclude that this type of

quote, had so completely failed that he conceived all further exertions on the subject quite fruitless as in it would be pointless to even try. But Bruno was about to have an experience that

“would completely change his mind. Yeah, so what happened? Well, I think it's best if I let him explain”

it. So here's an excerpt from a letter that he wrote to his granddaughter later on recalling his time working for the British Royal Navy and I'm just going to have you read it. About the year 1812 being then employed in the Dockyard at Chatham, I happened to see before me a piece of condemned timber, a portion of a keel of a ship, where in the worm, the charrato novellas, had made many erosions. And by erosions, he means tunnels, like tunnels through the wood. Okay, so in modern English,

like he saw a piece of timber that had been worm eaten along the Docks. Yeah, pretty much. Except that the so-called naval shipworm is not actually a worm. In reality, it's a strangely adapted by valve, mollusk. Oh, like a clam. Yeah, except specialized for boring holes. And it

“works like this. Like it's shell has evolved into a pair of grinding plates. And behind those”

plates, trails this long, soft, long-gated body that can reach a couple of feet in length. And he says terrifying, it sounds like something that I would eat eventually had it to as that pleasure, right? Yeah, hopefully it wouldn't eat you, right? I mean, you put some minute on it. Yeah, I like you scrape it out. It's going to be tasty. Yeah, and he didn't go quite that far, but he did pull out a magnifying glass, which is a thing that he was known to carry around

and went in for a closer look. And as he looked, he noticed that the walls of these boreholes that were carved by these worms seemed remarkably stable, even when they were in waterlogged and like rotting chunks of wood from old ships. They were protected. So, here's Bruno again from that same letter. I then sent to myself that these little things have made little tunnels.

So, might we by adopting some corresponding means of protection? I mean, that's basically like the

textbook definition about my brain, like so. So, what did Bruno notice about how the shipworms made their tunnels? So, the trick that he recognized and then set out to copy was that tripworms do two things at the same time. Even as they scrape out the wood in front of them and move forward into that hole, they extrude aligning that coats and reinforces the tunnel around and behind them. Okay, so while they dig, they also immediately shore up the tunnel around them, which describes

basically all excavations. So, how is this different other attempts? Yeah, well, so think of it this way, right? Miners used to working in hard soil could get away with digging for a stretch and then stopping for a bit and then going back and putting up supports behind them. Right. And Bruno recognized that that kind of iterative system just was not going to cut it under the temps because any gap in space or time between digging and showing up invited disaster. And so, with that in

mind, in 1818, he went and patented a machine that would work more like a shipworm, digging and

“then reinforcing simultaneously. So, how did Bruno's machine do that? Well, the crucial piece was”

what he called a tunneling shield. Basically, it was this massive cast iron frame that was pressed

flush against the face of the excavation. And under that shield, you'd have dozens of miners chipping away at the front of the tunnel, while brick layers short of the tunnel behind them. So, as the excavation progressed, the shield would be pushed forward and the newly exposed sections were immediately lined with cemented bricks. And so, it was all part of this smooth and continuous effort, like the shipworm tunneling and showing up behind itself simultaneously. But so cool.

Yeah, and really challenging, because, you know, Bruno had to piece together this system from all these moving parts and people because the technology at the time was not up to making like a machine that could automate all of this, right? It had to be people doing manual labor. And ultimately,

it worked. It took a really long time and it did not always go smoothly. But eventually, Bruno

completed the tunnel, spanning over a thousand feet under the temps in 1843. And that was the first tunnel built underneath the river anywhere in the world. Yeah, I mean, no. It was literally part of the pun, ground breaking. Nobody at Earth had ever made and walked through a tunnel like this

technology years later when they built out subway systems in London and across the pond in New York,

they use that same basic tunnel shield. That's so cool. And the funny thing is modern machines have if anything converge even more on those mollusks that originally inspired Bruno, because now we have machines with attachments that place precast concrete panels as the borer tunnels on birds, what is like that all in one thing. Okay, so despite all of the setpacks, we are really talking about a very straightforward case of biomimicry, like nature inspiring a human design.

“I guy sees something in nature copies it, perfects it, boom, success. Yeah, and that's why I wanted”

to start here, honestly, because I wanted to ground us in a success story where nature really was this direct inspiration for a human design. But there are a lot of other stories that don't perfectly follow that neat direct trajectory. Stories where the relationship between nature and human design inspiration is not quite so clear cut. Okay, so I'm very excited to have money the water's a little bit, so what is next? Well, a different sort of fishy biomimicry

with some real twists and strange turns, starting back in 2005 when Mercedes-Benz made a big splash with their biononic, which was this new concept car that boasted a biomedical origin story.

They claimed their design was the first of its kind to attempt a "complete" transfer from

“nature to technology input. Well, that sounds like vague nonsense. Yeah, I don't even know what that means.”

Yeah, well, the argument was essentially that biomimicry usually involves borrowing like a single feature or behavior from an animal, like a bird's feather or a whale's fin. But that their new car was modeled on an entire organism, the boxfish. Here's a picture of it. If you're featuring a boxy fish, because it's called a boxfish, you're right on the money. I mean, like it is a floating cube with fins. Yeah, exactly. And it's part of this family of really awkwardly angular fish, including

the cowfish and the trunkfish. Yeah. I mean, compared to the naval shipworm, this thing is adorable. I mean, it's like bright yellow spots on it. But I have to admit, this thing doesn't look aerodynamic at all. Like this seems like the opposite of an animal that you'd model a car on. So what was the logic

“behind modeling a vehicle on this boxy shape? Well, in big picture, the engineers at Mercedes”

were into this idea of biomanicry. And so they started scouring the animal kingdom for inspiration. And they wondered if a fish, for example, could provide that inspiration for a car design.

But cars have to be boxy. There's spaces that house humans. And a long sleek fish is just never

going to translate into a functional car. And so if there is a boxy fish that has evolved to be aerodynamic and boxy, that really could be a breakthrough that works all around. Okay. But what made them think that the boxfish was aerodynamic? Yeah. Well, it started with some real serious scientific research that they came across that was being done into the boxfish. In particular, a study being run by a team spanning UCLA, Caltech, and Woods Hole. And so they discovered that there are

nuances to the shape of the boxfish that help stabilize it, but you basically boxfish have these ridges that are called keels that run along their sides. And these help create little eddies which help them course correct as they swim through the water. Which as opposed is what you want to keep a car running smoothly like on a highway. It's like you want it to be stable. So that makes some sense. Precisely. And after reading the peer reviewed research papers, Mercedes engineers

even reached out and called up one of the researchers to learn more about their study. And then they took this step further and did research of their own. They had drag tests around 3D models of these fish that suggested that despite their squareish face, they were surprisingly streamlined at least in controlled conditions. And so in the end Mercedes designers concluded that the boxfish for all of its boxy this represented a quote, aerodynamic ideal in quote. And the bionic is the

car that they built. Yeah, exactly. They didn't just design it. They actually built it. And here's the picture of what it looks like, right? It's a car which true to its inspiration is relatively boxy as you can see. And it also has these angled ridges along the side that came from the boxfish

cute. I mean, it sort of looks like a lime green BW bug with some more squares feature. It's kind

“of like a van bug. You know, kind of. Yeah. Yeah. Yeah. That's a great description. And honestly,”

I also think it's pretty cute. And I'm not the only one. When Mercedes put this car out into the world, in the spotlight at a big public event, it was a hit. The bionic design got featured in Nat Geo. It was like installed in the momma. And for what was probably the most widely circulated example of automotive biomimicry in the world. Yeah. But I haven't seen one of these. So I'm assuming

it never got out of the concept car stage, right? Yeah. That's right. There is no commercial car

that evolved out of this. The bionic was really never truly made to go on the roads. It was just a concept car that got a bunch of attention and had a bunch of stories written about it. But you know, like that from their perspective, was kind of the whole idea in the first place. Mercedes might not have gotten a commercial car to sell. But they did get this great story that helped associate their brand with being like eco-friendly and cutting edge and tied into this legacy of natural design that had evolved

in like the organic elements over the years. Okay. But it's so far this seems like a pretty straightforward biomimicry story. Well, it would be if the story ended there. And for Mercedes, it basically did. But the fish scientists like scientists do kept going. And 10 years after the bionic's big reveal researchers with new technologies published new findings that painted a very different picture. The old data wasn't wrong exactly. It was just woefully incomplete. And long story short,

it turns out that the boxfish in its totality is definitely not a quote aerodynamic ideal. In fact,

if anything, it's basically the exact opposite. This is what they find out. Well, the new team

led by a biomorphology researcher named Sam Van Wassenberg modeled that blunt boxy front, plowing head on through the water. And look, it does do okay aerodynamically. As Mercedes had concluded, if it's going straightforward. But as soon as the fish turns its head, its aerodynamics are totally destabilized. Which doesn't sound like a great model for a car. Yeah, or definitely not the one they were envisioning, because it turns out that the boxfish's

super power is maneuverability, not aerodynamics. And if you actually watch them, they're not straight line swimmers or speed racers. They are these reef fish. And they spend their days threading their way through reefs and evading predators. These are animals that need to turn on a dime. So they're super agile and they flick their fins and rotate themselves in three dimensions, which is very cool and totally useful to them. But yeah, it's not what you're looking for in a

car. But the car you want to shape that can travel fast and you know, run smooth in one direction, even in high winds, just sort of stay out in course. And the boxfish for those purposes was essentially the worst fish to choose. So the biotic, it came out. It had a big splash. It was like sent around.

“I'm sure online a lot. When the new research came out, did Mercedes respond to it at all?”

Oh, no, not at all. And in fact, the bionics official webpage still describes the boxfish as having a quote, "highly streamlined body shape." Wait, so they saw a webpage with this thing? Yeah, yeah, it's still up there. It's still like part of their marketing material. It's like

the story of this thing was always the point. It was never about whether the car actually worked.

So this kind of bio-memory story. Would you classify it as more typical than like the Tam's tunnel success? Is this the type of thing that is mostly what happens when we try to use biomemetic design? Yeah, I would say that failures are definitely more common than success. But there's also like other kinds of non-successes, like basically sort of fake stories

“of having biomemetic inspiration or at least like vastly simplified ones, right?”

Right, just telling a biomemicry story about a product just so it sounds more interesting. Exactly. And there are a lot of those. And a classic example is this start-up that claimed to have invented a water bottle based on the Nami Desert Beetle, which is this insect that has actually evolved a way to capture water out of thin air. It collects and combines droplets on its back. And then those trickle down to its mouth so it can drink them. And so these

water bottles were, you know, going to do that same thing essentially and fill themselves up.

Yeah, no, no. It did not actually work. But it did get so much coverage and wired and MPR and BBC and like the list goes on. They even raised millions of dollars on the backs of those beetles.

“So yeah, the water bottle, like the bionic, it was really more about PR than real biomemicry. And honestly,”

it had less pretensions to even tie to science, I think, than the bionic did. Yeah, yeah. Okay, so we have one example of successful biomemicry with tunnel. We have the Mercedes example, which is really, you know, a success in marketing, but not really a successful as product. So what's next? Something that is, honestly, a little more complicated and less straightforward than either of those. Okay, we'll get to that after the break.

So we're back talking about biomemicry with Croco colster.

So our final story is about a structural design that you can find basically anywhere in the

aerospace industry. If you peel back a panel on a Boeing plane or a NASA shuttle, you'll see in a ray of hexagon. And these are called honeycomb sandwich panels. They look like and we'll instantly remind you of beehives. Yeah, so honeycomb panels, I've definitely seen them before.

“I think anyone who's paid attention to structures at all have seen them before.”

Were they inspired by bees? Well, that seemingly simple question is actually surprisingly difficult to answer. Because if you think about like people have been admiring an examining honeycomb since ancient times, like the earliest written account we have of why they might create hexagonal shapes dates back to 37 BC. And it was around this time that Geonometer has had figured out that hexagons are one of only three shapes that you can tile continuously and without gaps.

There are squares, which of course you can visualize in a grid. Yeah, like our logo. Yeah. Yeah, and triangles, which like if you, you know, can picture a truss or if you just kind of alternate up and down, you can see those tiling forever, right? And then there are hexagons. And of all that

“set hexagons are the ones that give you the most space as in the most area per unit of edge,”

which means that if you're tiling in a ray of shapes, these are the ones that let you use the least material. So for bees, that's more efficient and it makes building easier, but humans have been in effect from that same efficiency and other structural features, which we'll get too later. So in this case, because this is a super efficient structural solution to lots of problems, bees and engineers, you kind of just came up with the same solution. Yeah, that makes total

sense to me. But in the midst of the modern era, another contingent came along and saw honeycombs as examples of intelligent design. In the 1800s, one clergyman slash naturalist, lot of bees has, quote, heaven instructed mathematicians in, quote, Darwin actually saw this line of thinking as a big threat to his work, even in the 1850s, as he was writing on the original species. Huh, so why would the bees being good at geometry be a problem for evolution? Great question,

and so basically, if evolution is incremental, how do bees arrive at a perfect geometry? What are the

steps they take? Because, you know, a slightly off incomplete hexagon isn't a natural step towards me here, good hexagon. It's just a bad shape. And so where do we find the in-between versions? And if there aren't any, the natural theological argument goes, somebody, or some God, must have handed the bees the answer. Also, I suspect there was kind of a level intuition behind all of this, like, if you look around at the natural world, you see curves and fractals and all these chaotic

things, but precise angular polygons are pretty weird and rare. Yeah. And so they seemed just visually, like, if the exception to the norm, right? Right. Right. So I can sort of see the argument or why it was complicated. And that was what had Darwin worried. Yeah, in fact, so much so that he actually kept bees to research and experiment on while he was writing origin. And what he observed is that bees don't build hexagons outright. They actually dig roundish holes that are

well basically be shaped, right? But when a bunch of them do that, you know, in a grid, they end up

bumping into each other. And as they approach their neighbors, they naturally make walls around

like they dig around hole and you put up some walls for support. And they're surrounded by other

“neighbors who are doing the same thing. And the sides of the circular holes kind of push against”

each other and flatten out so that you get a hexagon shape. Exactly. None of which is to say that honeycomes aren't natural wonders. In fact, Darwin was a huge fan. And after he finished his research with these bees, he organized a whole section of origin around them and their honeycomes,

in which he argued that these were amazing examples of the power of evolution. And here's

a little excerpt from that chapter. He must be a dull man who can examine the exquisite structure of a comb so beautifully adapted to its end without enthusiastic admiration. We hear from mathematicians that bees have practically made their cells of the proper shape to hold the greatest possible amount of honey, with the least possible consumption of precious wax in their construction. And you know, there were already all of these connections, but when Darwin published origin,

“honey bees and hexagons became stuck together in one of the most popular science books of the”

century. And we're essentially an extricably linked ever since. So when hexagonal panels are created around a century after Darwin, of course, they get named honeycomb panels. Right. Right. I mean, you're just naming them after what they look like. You know, like that makes sense to me. But in terms of biomemicry, in terms of our subject today, were the aerospace engineers that who were using honeycomb shapes, were they building off of the logic of bees or were they

building off the legacy of human researchers who came before them? I mean, yes. I would say both, all of the above. And I, I rather dig that ambiguity like there is no simple straight line from nature to humans. And you know, after 2000 plus years of honeycomb history bringing us to the modern aerospace industry, you might think that that would be the end of the story. But I have one last little twist for you. Oh, awesome. Okay. One of you more. Yeah. So in the late 2010s,

this 3D printing expert named Drove Bhate got to thinking about honeycums. And he wondered if there was maybe more to them than this platonic ideal of this particular six-sided polygon. So he saw out an expert in endomologist named Clint Pinnock, who was working at an actual biomemicry center at Arizona State. And Clint was shocked to discover that Drove, who had built a whole career

“on honeycomb structures, had never even seen an actual honeycomb in real life. You know what?”

I worked in science for a long time. This actually does not surprise me. Right? Yeah. Because, you know, most engineers they don't need to bother with bees. They know the shape, right? But Clint sees this. And he starts showing Drove actual honeycums. And together, they begin to look at how these vary by species. And they observe that real honeycums are actually quite a bit different from those sort of rigidly repetitive human-made honeycomb

panels. All right. So how did they differ? Well, the easiest difference is at the corners, at these intersections that are sharply angled in human honeycomb panels. But in nature, often have different degrees of rounding. Yeah. I mean, that makes sense to me because as Darwin described, you know, like the bees are kind of making a circle. And it turns into a hexagon. So like not having other circles around you means that the edges are more rounded. Yeah. Yeah.

And so Clint and Drove use 3D printing to replicate those curves. And what they found is that

they can offer real structural benefits. So ultimately, the pair got massive funding to look

even more closely in the x-rayed and characterize these different comes from dozens of different species of bees and wasps. And they documented all kinds of smaller details, like the variations in the wall thicknesses and the way that separate comes sections are like joined together and sure enough. Suddler elements of the cone shape were found to improve structural performance with potential aerospace applications. Wow. So like even in the Swiss age,

bees are building better hexagons than we do. Yeah. I mean, it depends on the bee and the application. But we are definitely still learning stuff from them, which is crazy. I love that story. I mean, it makes me think about the, you know, the very simple biometrics story that we started with, this sort of kingfisher bullet train story. You know, it's cool. It's easy to convey. But it's pretty flat and flavorless by comparison. Yeah. Well, I mean, I don't know if I go that far

because there's something I really still dig about those straight forward biometrics stories.

But sure, yes, there's something also richer, ultimately, about ones like the honeycomb story,

conversation with one another. Yeah. Like a recursive discussion between nature and humans about,

“you know, the virtues of shapes like us. Curt, this was so much fun. I, I appreciate this”

tour through various kinds of biometrics. Of course, Roman anytime. 99% invisible was reported this week

by Curt Colstead, produced by Jacob Medina Gleason, and edited by Emmett Fitzgerald,

“mixed by Martin Gonzalez, music by Swanry Owl, fact checking by Graham Haitia.”

Kathy 2 is our executive producer, Delaney Hall is our senior editor.

The rest of team includes Chris Brube, Jason Delion, Christopher Johnson, Babynlay,

“Lashma Dawn, Joe Rosenberg, Kelly Prime, Talon and Rain Stradley, and Me Roman Mars.”

Then 99% of his below-go was created by Stefan Lawrence. We are part of this series XM podcast family, now headquartered six blocks north in the Pandora Building. In Beautiful. Uptown, Oakland, California. You can find us on all the usual social media sites as well as our own discord server. There's a link to that as well as every past episode of 99PI at 99PI.org.