Spiders Ingest Nanotubes, Then Weave Silk Reinforced with Carbon | Hacker News Reader

Spiders Ingest Nanotubes, Then Weave Silk Reinforced with Carbon

technologyreview.com

272 pointslelf79 comments

I just wrote this up myself. The results are remarkable, but the credit seems entirely due to the spiders. Well, not entirely, but the data is so limited! They only got a handful of spiders, from the lab's back yard essentially, and a bunch of them died from nanomaterial exposure, malnutrition, or both after 1 trial!

Yet despite the bargain bin trappings, the results are so incredibly cool! The spiders just... incorporated carbon nanotubes and graphene into their silk-spinning process? What?! What's the mechanism?! No one knows! Who would have guessed this would work? It sounds like a joke experiment they cooked up while waiting for the glassware to bake!

Hopefully a more rigorous study replicating and expanding on these results will appear. But it just blew my mind the way this particular science appeared.

Is there a word like serendipity that means "found as a joke" instead of "found by a fortunate accident?"

Not a single word, but http://catb.org/jargon/html/H/ha-ha-only-serious.html is related.

Not a word, per se, but this mechanism of discovery tends to correlate with being the sort of thing that wins an Ig Nobel prize.

It seems this is how the most remarkable scientific discoveries happen, though -- purely by accident or as part of a wild trial "Hey, what if we just tried this...?"

This [1] is a pretty good description of the spider silk stucture. Turns out it's a self-assembled liquid crystal composed of oriented rods of a hydrophobic protein (an alanine/glycine co-polymer for those who care). It's not hard to imagine how a carbon nanotube could substitute for one of those if it's around in the soup...

[1] http://www.chm.bris.ac.uk/motm/spider/page3.htm

A guess at the mechanism: the silk protein selection algorithm is an accept-first filter, the silk ducts being somewhat like human mammary glands. Anything the spider isn't specifically pulling back into its own blood as needed would then end up as an impurity in the webbing. (Easy experiment to do in its own right, but from a quick search I can't find evidence to support or refute it.)

Past that, the nanotubes just have to get locked into the matrix of the silk in the right orientation... which could just happen to anything of the right dimensionality in the silk as it anneals into shape.

> somewhat like human mammary glands.

This reminds me of a story of dolphins, who apparently suffer a lot from mercury poisoning, mostly caused by the smog of unfiltered coal plants entering their ecosystem. One issue of mercury poisoning is that the body has no way to get rid of it - it gets stored in the fats, IIRC. Unless you're a mammalian mom. Then the body gets rid of mercury through your milk. Mercury is most lethal at the infant age. So in short, most dolphin mothers' firstborns die [0].

Anyway, perhaps the carbon fibers are actually toxic, and the only way the spiders can get rid of the material is through their silk?

[0] http://www.takepart.com/article/2015/02/11/revealing-cove-do...

> Who would have guessed

Except for not being a dog, such a spider is anticipated in Goethe's little poem «Annonce» (Advertisement):

    A little dog is sought
    that never barked nor bit
    takes broken glass as feed
    leaves diamonds as - -

(my own translation, but wouldn't be surprised if it has appeared in these words before)

Yeah, pretty good!

    Ein Hündchen wird gesucht,
    Das weder murrt, noch beißt,
    Zerbrochene Gläser frißt
    Und Diamanten scheißt.

> Und Diamanten scheißt.

chuckles to self

Nice discovery and thank you for sharing it. Concerning the article, there are a lot of superlatives which sometimes makes me wonder whether the author is overenthusiastic and still rational; Therefore a couple of comparions would be welcome for people who didn't study material resistance, e.g. "Such a web can hold a 2kg spade if it happens to hang in your garage". Can it?

I agree, so I asked my material scientist friend. Based on the strand thickness in that microscope image being approximately 8 microns, a single strand can hold about 250g. So a web would probably hold a spade, depending on how well it sticks. Incidentally, if you need a material scientist, OracleCarbon hangs out in IRC in #xkcd on the Foonetic network and is happy to answer stuff like that.

I was actually joking when I thought of a spade, I'm impressed!

> Who would have guessed this would work?

A lot of people? The carbon has to end up somewhere. I don't see this as surprising at all, any more than it's surprising that if you, a human, eat a lot of arsenic, you'll add some of it to your hair. Growing hair and growing silk are not fundamentally different activities.

This is fascinating stuff - now they just need to feed genetically modified spider-goats graphene and see what happens!

http://www.bbc.co.uk/news/science-environment-16554357

http://en.wikipedia.org/wiki/BioSteel

So, for those that don't remember what "regular" spider silk is like, or kevlar:

  nanomagic spider silk:   5400 MPa (5.4 GPa)
  Spider silk:             1600 MPa
  Silkworm silk:            500 MPa
  Aramid
   (Kevlar or Twaron):     3620 MPa
  Steel:                    450 ~
                           2600 MPa

If I'm reading http://en.wikipedia.org/wiki/Ultimate_tensile_strength correctly (and comparing the right numbers with the ones from the article...). At least kevlar seem to be in the same ballpark.

Interestingly the spider silk of 5.4 GPa has higher tensile strength than the specimens of "pure" carbon nanotubes of 2cm measured in labs at 3.6 GPa. The theoretical limit of cabon nanotubes is said to be at 300 GPa, and it's assumed that materials with about 130 GPa of tensile strength would be needed for the "rope" of an space elevator.

Can a human actually break such a tiny web?

According to wikipedia, the diameter of natural spider silk is 4µm, which is a cross section area of 1.26e-11 m². Multiplied by the tensile strength of natural spider silk (5.4 GPa) gives the capacity to lift 68 milinewtoms, or 7 Grams!

http://www.wolframalpha.com/input/?i=%284e-6+meter+%2F+2%29%...

It's only ~4x stronger than regular spider silk, so I'm going to say yes.

Thanks. Those numbers were sorely missing from the article.

> “This new reinforcing procedure could also be applied to other animals and plants, leading to a new class of bionic materials,”

how about silk worms? at least we know how to handle those in bulk.

There's a lot of effort going into just that, though there are some stumbling blocks researchers are still working their way through before we start seeing production scaled up.

http://news.discovery.com/tech/spider-silk-silkworms-genetic...

But how about just natural silk with carbon nanotubes? Sure spidersilk is "the greatest" -- but maybe nano-augmented regular silk is better than, well regular silk?

[ed: insert dystopian sci-fi plot of scattered survivors of the nano apocalypse growing bullet proof vests from silk worms found in old industrial (nano)waste sites...]

What do you mean by "natural silk".

Where do you think "natural silk" comes from?

I meant silkworm-silk. I wonder if silkworms can be made to make regular silk that's augmented with nanotubes for a similar (relative) increase in strength, with similar easy process (shower silk-worms and their food with water with nanotubes etc).

"Natural silk" aka "silk" comes from silkworms.

Right. I was wondering if silk worms could be made to produce nano-silk if drenched in nanotube-water, like the spiders (or fed leaves dipped in nanotube-water etc).

[ed: I probably should've written "normal" silk, not natural silk...]

I don't know if it's a function of thickness, or if they've beaten these researchers to the punch, but black widow spiders spin by far the strongest thread I have ever encountered. There's never any doubt when I encounter a black widow web, and that's how I know to proceed with caution, when I'm working in my garage on the next Google haha.

They might be twining multiple threads (each themselves consisting of multiple strands) together to make an especially strong dragline or something. The giant riverine orb spider is on record as making the strongest thread, but that might be under certain conditions (like what comes out of the spinnerette (sp?), no weaving allowed) or the like.

Are you able to break their spidereb with your hands?

This isn't something I'd be willing to try, for a black widow web...

At Brazil we have a related (and extremely creepy - have you ever seen a spiders swarm?) but harmless species.

Yes, one can break its web with the hands, but not without a conscious effort.

So it doesnt just come apart like normal spiderwebs?

I imagine breaking carbon nanotubes with bare hands...

Ok that is pretty cool, combine it with this work (http://www.eurekalert.org/pub_releases/2010-05/tum-ihs051010...) where folks are figuring out how to spin spider silk without the spiders, and you've got an interesting start.

So what happens when these spiders start reinforcing their exoskeletons with the ingested nanomaterial? Angry, eight-legged predators in ultratough kevlar, shooting indestructible web, that's what :)

Just add some mood enhancers to the fiber soup to counteract the angriness.

    > exactly how the spiders incorporate carbon nanotubes and graphene flakes into their silk is not clear

This confuses me. Surely they must've had some kind of hypothesis for this, or are they just going around spraying all kinds of creatures hoping they gain super-powers?

Well, spiders eat stuff, and poop out magic thread.

So change their diet, you change the thread...

Luckily for all those times I've walked face first into a spider's web:

Spider silk != Poop

The most interesting part of the article for me was:

"Nobody has discovered an efficient way to harvest spider silk, although not for lack of trying. "

I would love to know more about these attempts. Searching google brings up doesn't help much as the keywords "mine" and "web" can have a wholly different connotation.

Story of how they weaved the only spider silk rug in the world.

Spider Wranglers Weave One-Of-A-Kind Tapestry http://www.npr.org/templates/story/story.php?storyId=1132233...

The efficient way is to genetically-engineer goats to produce the silk from their teats.

Strong enough for space elevator core?

What would a bunch of spiders do with a space elevator?

Laugh it up while the Ur-Quan take over the galaxy.

All hail Dogar and Kazon!

Apparently not. From other comments:

cnvogel: it's assumed that materials with about 130 GPa of tensile strength would be needed for the "rope" of an space elevator

e12e: nanomagic spider silk: 5400 MPa (5.4 GPa)

So it basically looks like whatever the spider consumes (as food?), it will incorporate into its silk if not needed. In the interest of science, might be interesting to try different food coloring, spices/aromas based sprays to see if that would make the spider silk more colorful or create fragrant webs -- Also, this could be a special evolutionary trait to attract food (right aroma/color?)

Just when I'm full up on superhero themes it gets all interesting again.

Peter parker was just your average day Pholcidae spider, until one fateful day when he was exposed to experimental carbon nano-tubes. Now he must decide, will he use his new found super web powers for good, or for personal gain?

Time to make another movie reboot.

A third (reboot) is already planned, you mean you want a forth?!

One where he starts as an actual spider and gets bitten by a radioactive man, just to give us something different forth time around.

He could team up with Man-Bat - http://en.wikipedia.org/wiki/Man-Bat

Just like "The Spider", a villain in Rat-Man: http://en.wikipedia.org/wiki/Rat-Man_%28comics%29#The_Spider It can't climb walls, but has acquired human personality traits: selfishness, greed and cruelty.

"Spiderman and the Space Elevator"

I'm just imagining the poor spiders that can't cut down their own webs when they want to re-weave them, or accidentally catch birds.

Skitter[1] would have been all over this.

[1] http://worm.wikia.com/wiki/Taylor_Hebert

Incredible. I bet the results could be improved even further with artificial selection to get spiders that are even better at incorporating carbon into their silk

And Pholcidae are not even the creators of the stronger webs in the world. With about 200.000 different types of spider silk in the planet, is really exciting to dream about what major league players like Nephila or Caerostris could achieve with this stuff.

“This new reinforcing procedure could also be applied to other animals and plants, leading to a new class of bionic materials,” they say.

Could it be applied to human stem cells or bone marrow? That'd be neat.

Goes to show that us humans aren't the best at making everything. Wish I thought of this when studying nanotechnology in grad school.

We're not the best at making anything. We're pretty good at using things, though.

I'm not sure that's strictly true. I've not yet heard of another species as good as us at making, for example, cars, or computers.

There are some ways we could argue that turning dirt into a car is really just really, really, good using ..

matching the toughness of state-of-the-art carbon fibers such as Kevlar

I don't think I would call kevlar a carbon fiber, is more like nylon.

This is SO cool. I'm going to start adding nanotubes to my morning coffee so I can write the unbreakable codez!

I smell an origin story for Peter Parker's web shooters in the upcoming second Spider-Man reboot.

FINALLY, A SPIDERMAN QUOTE.

Seriously, I've been reading every comment. It took me almost 20 minutes to find a spiderman reference. Frankly, that's surprising...

Are these strong enough to build a space elevator?

From other comments:

cnvogel: it's assumed that materials with about 130 GPa of tensile strength would be needed for the "rope" of an space elevator

e12e: nanomagic spider silk: 5400 MPa (5.4 GPa)

It's not a bug it's a feature.

Tldr its stronger than kevlar they say

Cool!

Wake up sheeple! Isn't this exactly how the Arachnids of Klendathu came into being?

This is sad, in a way; once I achieve my dream of exterminating all the spiders there won't be any left to spin this nanotube-reinforced fiber.

Unless the spiders start wearing spider nanotube silk weaved spider kevlar

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