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Artificial superstrong silkworm silk surpasses natural spider silks
- anu7df 4y agoTensile strength of 2 GPa for this silk compared to 0.4 to 0.8 GPa for steel. Really cool.. This is without including the strength to weight aspect!
- fire 4y agoI actually don't understand how they do tensile strength testing between steel and silk - doesn't silk stretch or yield?
- anu7df 4y agoElastic stretching, the one that reverses completely on taking the load off, is the regime where there is a linear relationship between the stress load and the stretching. This should be seen as different from yielding which in mechanical testing is an irreversible change usually signifying a destructive change in the material. So, yes, silk stretches but is not damaged while doing so and the resistance it provides at the time relates to its strength.
- TheSpiceIsLife 4y agoSteel also undergoes elastic deformation, stretches but is not damaged while doing so, up until the yield point. https://youtu.be/D8U4G5kcpcM https://youtu.be/D8U4G5kcpcM
- nico 4y agoCould reinforced concrete be made with silk instead of steel?
- greenpresident 4y agoMy high school physics understanding of reinforced concrete is that the coefficients of expansion for steel and concrete are similar to a degree that it is very resilient to heat stress. I doubt that's the case for silk.
- Gravityloss 4y agoAlso, steel, while more expensive than concrete, is still cheap compared to many other solutions for tensile strength. Also it tensile strength is sufficient for steel reinforced concrete. Concrete itself has performance limits for compression strength.
- adrian_b 4y agoThe problem for such an application is not the strength, but the chemical stability in time. For it to be competitive, it would be necessary for the rate of hydrolysis of the protein fibers (which breaks the fibers) in an alkaline environment to be less than the rate at which rusting diminishes the strength of steel bars. This is very unlikely. At most there might be a chance for such fibers to be used for reinforcing some other kind of cement, less alkaline than the common cements. Also, for reinforcement applications, good adhesion between the reinforcing material and the reinforced material is necessary, which for silk vs. a mineral cement would need some kind of extra adhesive coating of the fibers, with adequate properties, which might be hard to discover.
- mkingston 4y agoThese are of course, good points; cement probably being more porous than many people perceive. Just a little (hopefully interesting) speculation: adhesion might be less important, or entirely unnecessary if the reinforcing material isn't arranged like rebar. I.e. if it were just a tangle in the concrete.
- onlyrealcuzzo 4y agoCouldn't you coat the silk in some other material to get around that?
- baxuz 4y agoI haven't found any info on the thickness of the material for those tensile strength measurements. How does it compare to something like Dyneema?
- fvdessen 4y agoApparently Dyneema has a tensile strength of 3.5Gpa https://matweb.com/search/datasheet.aspx?matguid=4481722d60e54cc3b3c112eb3d4b9d02&ckck=1 https://matweb.com/search/datasheet.aspx?matguid=4481722d60e...
- rmah 4y agoWhat makes steel awesome is that the properties can be tuned across a wide range. Sure, cheap structural steel has a tensile strength of about 0.4 to 0.5 GPa and the most common types (i.e. cheapest) of "high strength" steel can reach 0.8 GPa. But... some specialty steels can reach well over 2+ GPa. The steel for some cables have tensile strengths of 2.0 GPa, maraging steel for can reach 2.7 GPa. There's a good reason steel is still so widely used. It's awesome!
- staticassertion 4y agoVery interesting. Currently there are genetically modified silkworms that produce spider silk but it's not quite as good as the real thing. This method basically tries to "up" the silkwork silk to make it better. The metric they use is tensile strength. Curious to see applications.
- anu7df 4y agoThere are also genetically modified goats that produce spider silk in its milk. The protein that is, not long strands in the milk :)
- richardw 4y agoTIL spiders create different silk for draglines and eggcases.
- JumpCrisscross 4y agoSay this could be mass produced. What are the beachhead markets? What are the moneymakers?
- 6stringmerc 4y agoBulletproof backpacks for kids in the USA. Only partially kidding, as Kevlar vests are the standard I believe…
- staticassertion 4y agoIf transporting steel wiring is a major cost for you you could reduce that cost significantly by transporting far lighter, thinner strands of these fibers. That would have to assume that you can make up any increased costs of using the silk, of course.
- drewm1980 4y agoTLDR; they reprocess natural silk from silkworms to produce silk fibers with better tensile strength. This is partly achieved by doing a better job of washing out non-strong compounds from the fiber, so the yield is strictly lower than that for natural silk. This process still involves boiling silkworms alive. This contrasts from biotech based fibers, e.g. https://boltthreads.com/technology/microsilk/ https://boltthreads.com/technology/microsilk/ , which is produced by genetically modified yeast.
- jjcon 4y agoReminds me of biosteel — silk made from transgenic goats milk: https://en.wikipedia.org/wiki/BioSteel_(fiber) https://en.wikipedia.org/wiki/BioSteel_(fiber)
- dsign 4y agoIMO, fibers with very high tensile strength have only two applications worth speaking of: a) Space elevators (but the tensile strength required for that is too high and we are still not close enough), and b) Large O'Neill cylinders, in the radius of about 50 kilometers (about 30 miles). With regards to tensile strength, these would require something with the strength of graphene. This particular fiber seems to have 2 GPa of tensile strength, which is only good for a smallish O'Neill cylinder.
- thorncorona 4y agoI can think of a couple: - Durable stringy clothing items - Thinner ropes? Particularly relevant is for safety applications. - Fiber ropes are particularly advantageous when compared to steel ropes in applications that require repeated bending.
- beefield 4y agoRegarding ropes, for most practical applications I can think fro the top of my head, tensile strength is not actually that much of a limiting factor (especially with dyneema), but more the abrasion resistance and how easy it is to handle a rope. I mean, you could in theory rappel from something like 2mm dyneema line with very comfortable safety margin on tensile strength alone, but 1. keeping a say 60m long 2mm line untangled is a serious headache, and I would not be comfortable holding my weight on the 2mm rope while letting it scratch against a rock wall .
- netjiro 4y agoif the load bearing core is miniscule and light you have plenty of mass and radius available for abrasion resistance, handling properties, etc ...
- beefield 4y agoYes, but we are there already in many applications where we need to pad the core for abrasion and handling. Making the core even more smaller makes no big benefit - unless it is substantially cheaper than the competition. And to be clear, I believe there are multiple applications for higher tensile strength fibers. I just can't see that many applications where thinner ropes than current technology produces would be a game changer.
- s3ctor8 4y agoWhen I read the title, my mind went to "She sells sea shells on the sea shore".
- DonHopkins 4y ago>Unlike silkworms, spiders cannot be farmed due to their territorial and aggressive nature. They just need to breed friendly docile spiders. https://www.getsurrey.co.uk/news/uk-world-news/royal-holloway-researcher-discovered-worlds-15824383 https://www.getsurrey.co.uk/news/uk-world-news/royal-hollowa... >Has a Royal Holloway researcher discovered the world's friendliest spider?
- ncmncm 4y ago2 GPa is 2GN/m^2, or 200kN/cm^2, which supports 20Mg. Taking silk density as 1 g/cm^3, that is 20M cm, or 200,000 m, or 20km. Silk density is actually ~1.37 g/cm^3, so derate the above to 14.6 km. IOW, a silk cable can support 14.6 km of rope hanging below it. Not close to strong enough for a Space Elevator.
- telchar 4y agoYou lost a zero in there, so more like 146km.
- Gravityloss 4y agoExamples here, one can sort by breaking length: https://en.wikipedia.org/wiki/Specific_strength https://en.wikipedia.org/wiki/Specific_strength (2 GPa) / (1400 kg/m^3 x 10 m/s^2) = (2e9 N/m^2)/(1.4e4 N/m^3) = (2e5/1.4) m = 140 000 m = 140 km P = F/A, F = M x g, M = A x L x rho L = M/(A x rho) = (F/g)/(A x rho) = (F/A)/(g x rho) = P / (g x rho)
- ncmncm 4y agoOops, tx. Seemed low.
- cstross 4y agoNot enough for a space elevator on Earth, but definitely in the range you need for very long suspension bridges -- think in terms of railway bridges over the English Channel, the Straits of Gibraltar, the Irish Sea, and (with causeways/island hopping) the Bering Straits.
- dekhn 4y agoThat's still only the very first step to building a Space Elevator. And, the product, if it had those properties (when deployed in the wild) would find more profitable use in terrestrial applications. We will be burning rocket fuel to get to space for the foreseeable future. Better to launch enough to build in-space processing facilities if you're really committed to dual-homing humanity or making space travel more cost effective.
- 4y ago
- chatterhead 4y agoThis is really neat. I hope they are secretly creating a hand-based slinger for this super strong spider silk.
- Blammar 4y agoI want to see a braided rope made with this stuff...
- 14 4y agoI would imagine you could use ultra thin rope for heavy loads. I worked at a bungy jump place once and we had members of the Canadian military come to our bridge to test some very thin paracord. The rope they used did not look like it would be able to hold them but it did. But this silk is obviously way stronger then what they had I could only imagine how thin it would be and have the same strength
- shellfishgene 4y agoThere are artificial fibers that are much stronger, and you can buy rope made from them.
- JKCalhoun 4y agoI want to see a space elevator. A guy can dream?