Solved: Mysteries of Spider Silk

[rhoenix]

Scientists at ASU are celebrating their recent success on the path to understanding what makes the fiber that spiders spin -- weight for weight -- at least five times as strong as piano wire. They have found a way to obtain a wide variety of elastic properties of the silk of several intact spiders' webs using a sophisticated but non-invasive laser light scattering technique.

"Spider silk has a unique combination of mechanical strength and elasticity that make it one of the toughest materials we know," said Professor Jeffery Yarger of ASU's Department of Chemistry and Biochemistry, and lead researcher of the study. "This work represents the most complete understanding we have of the underlying mechanical properties of spider silks."

Spider silk is an exceptional biological polymer, related to collagen (the stuff of skin and bones) but much more complex in its structure. The ASU team of chemists is studying its molecular structure in an effort to produce materials ranging from bulletproof vests to artificial tendons.

The extensive array of elastic and mechanical properties of spider silks in situ, obtained by the ASU team, is the first of its kind and will greatly facilitate future modeling efforts aimed at understanding the interplay of the mechanical properties and the molecular structure of silk used to produce spider webs.

The team published their results in a recent issue of Nature materials and their paper is titled "Non-invasive determination of the complete elastic moduli of spider silks."

"This information should help provide a blueprint for structural engineering of an abundant array of bio-inspired materials, such as precise materials engineering of synthetic fibers to create stronger, stretchier, and more elastic materials," explained Yarger.

Other members of Yarger's team, in ASU's College of Liberal Arts and Sciences, included Kristie Koski, at the time a postdoctoral researcher and currently a postdoctoral fellow at Stanford University, and ASU undergraduate students Paul Akhenblit and Keri McKiernan.

The Brillouin light scattering technique used an extremely low power laser, less than 3.5 milliwatts, which is significantly less than the average laser pointer. Recording what happened to this laser beam as it passed through the intact spider webs enabled the researchers to spatially map the elastic stiffnesses of each web without deforming or disrupting it. This non-invasive, non-contact measurement produced findings showing variations among discrete fibers, junctions and glue spots.

Four different types of spider's webs were studied. They included Nephila clavipes (pictured), A. aurantia ("gilded silver face"-common to the contiguous United States), L. Hesperus the western black widow and P. viridans the green lynx spider, the only spider included that does not build a web for catching prey but has major silk elastic properties similar to those of the other species studied.

The group also investigated one of the most studied aspects of orb-weaving dragline spider silk, namely supercontraction, a property unique to silk. Spider silk takes up water when exposed to high humidity. Absorbed water leads to shrinkage in an unrestrained fiber up to 50 percent shrinkage with 100 percent humidity in N. clavipes silk.

Their results are consistent with the hypothesis that supercontraction helps the spider tailor the properties of the silk during spinning. This type of behavior, specifically adjusting mechanical properties by simply adjusting water content, is inspirational from a bio-inspired mechanical structure perspective.

"This study is unique in that we can extract all the elastic properties of spider silk that cannot and have not been measured with conventional testing," concluded Yarger.

In terms of pure materials science, this is great news, for so many reasons. Artificial silk being a real thing could jumpstart a couple industries, and push forward some interesting product advances because of it.

[Batman]

This is probably an incredibly stupid question (not to mention one I've probably asked-repeatedly-before-but if spider silk is so awesome why don't we breed them like mad?

[rhoenix]

This is probably an incredibly stupid question (not to mention one I've probably asked-repeatedly-before-but if spider silk is so awesome why don't we breed them like mad?

We do.

It's nowhere near enough.

From google:

However the production of spider silk is not simple and there are inherent problems. Firstly spiders cannot be farmed like silkworms since they are cannibals and will simply eat each other if in close proximity. The silk produced is very fine so 400 spiders would be needed to produce only one square yard of cloth. The silk also hardens when exposed to air which makes it difficult to work with.

[General Havoc]

That hasn't stopped some people from trying.

[frigidmagi]

Clearly I need someone mad enough and smart enough to breed some sort of vegan spider...

I think I best call up Comrade Tortoise...

[Batman]

Can't you just have the spiders feed on cattle or something?

[rhoenix]

Can't you just have the spiders feed on cattle or something?

Do you want to be the brave intrepid farmer to collect silk made from spiders large enough to feed regularly on livestock?

Actually, that explains those bits from The Hobbit and LOTR - Sauron had initiated a spider silk breeding program for his kingdom.

[frigidmagi]

Makes sense, spider silk would be a hell of a trade good and rather decent armor with the right treatments...

Although given that spiders have a lower carbon footprint and lower environmental impact then massive strip mining and foundaries that devour entire forests to make... some thousands swords and armor pieces... One would think it would be the elves who came up with it not the OrcLord (hmmm, there's an idea there).

Behold the doom of men! Orcs in Spider silk armor! Comfortable, luxurious spider silk that can block arrows and swords.

[rhoenix]

Makes sense, spider silk would be a hell of a trade good and rather decent armor with the right treatments...

Although given that spiders have a lower carbon footprint and lower environmental impact then massive strip mining and foundaries that devour entire forests to make... some thousands swords and armor pieces... One would think it would be the elves who came up with it not the OrcLord (hmmm, there's an idea there).

Behold the doom of men! Orcs in Spider silk armor! Comfortable, luxurious spider silk that can block arrows and swords.

Spider Silk. Pioneered by elves, and refined by Sauron. From our factories to your homes, with the consistent fit and comfort you'd expect from your local Dark Lord Mart. Now in non-grey colors!

[frigidmagi]

Spider Silk. Pioneered by elves, and refined by Sauron. From our factories to your homes, with the consistent fit and comfort you'd expect from your local Dark Lord Mart. Now in non-grey colors!

Try our new colors Still Bleeding Red or Screaming In Fear Yellow in addition to classic Joy Was Outlawed Grey and Never Seen The Sun Black!

Coming soon, OH God MY EYES Orange!

[General Havoc]

Not to channel CT here, but that raises a good point:

Why are spiders always the servants of the evil dark lords in fantasy? Why wouldn't the awesome nature-worshiping elves be totally down with giant spiders?

[frigidmagi]

Because most people... Most normal people find spiders creepy and scary. Much like how back in the day wolves were always in service to Ye Powers of Darkness, because the average dude was scared shitless of them.

[General Havoc]

Hey, I find Spiders creepy and scary too, but just thinking logically, they're no more carnivorous than eagles, who are always shining allies of the side of virtue. And Elven Spider-cavalry would be extremely badass.

[Dark Silver]

Well fuck.....now I have a entirely scientific idea for new armors in Final Flamewar......

the Frigid will be decked out in Spider silk Armor in that game . . .

[rhoenix]

Hey, I find Spiders creepy and scary too, but just thinking logically, they're no more carnivorous than eagles, who are always shining allies of the side of virtue. And Elven Spider-cavalry would be extremely badass.

That would definitely be a reason to not assault Mirkwood. "Hey, I heard they only have light cavalr....OH FUCK THEY'RE RIDING GIANT BROWN RECLUSES"

[B4UTRUST]

Not to channel CT here, but that raises a good point:

Why are spiders always the servants of the evil dark lords in fantasy? Why wouldn't the awesome nature-worshiping elves be totally down with giant spiders?

I'm pretty sure there are already elves who are all about the spiders. They're called the Drow.

[Batman]

Yeah, but the drow are generally depicted as, you know, evil.
And the Bard's Tale novels and Wizardry if nothing else depicted Arachnids as essentially, just another species.

[Josh]

Fuck fantasy, we're now reaching Alpha Centauri levels of tech.

Dibs on the Weather Paradigm.

[B4UTRUST]

Yeah, but the drow are generally depicted as, you know, evil.

Details details

Fuck fantasy, we're now reaching Alpha Centauri levels of tech.

Dibs on the Weather Paradigm.

I call biomachinery then?

[Batman]

as long as everybody remembers I've had materials that make spider silk look like tissue paper and are infinitely compressible (or near enough as not to make a difference) for more than half a century. I had about a lightsecond's worth of unbreakable rope in my utility belt before I started wearing the one that actually had pockets.

[Josh]

Yeah, but the drow are generally depicted as, you know, evil.

Details details

Fuck fantasy, we're now reaching Alpha Centauri levels of tech.

Dibs on the Weather Paradigm.

I call biomachinery then?

Damn, the Cyborg Factory was my second choice. If it hadn't been so damned cold and windy yesterday I would've totally run with it.