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A research team from Tsinghua University in Beijing has developed a fibre they say is so strong it could even be used to build an elevator to space.
They say just 1 cubic centimetre of the fibre – made from carbon nanotube – would not break under the weight of 160 elephants, or more than 800 tonnes. And that tiny piece of cable would weigh just 1.6 grams.
"This is a breakthrough," said Wang Changqing, a scientist at a key space elevator research centre at Northwestern Polytechnical University in Xian who was not involved in the Tsinghua study.
The Chinese team has developed a new "ultralong" fibre from carbon nanotube that they say is stronger than anything seen before, patenting the technology and publishing part of their research in the journal Nature Nanotechnology earlier this year.
"It is evident that the tensile strength of carbon nanotube bundles is at least 9 to 45 times that of other materials," the team said in the paper.
But hey, it's China, please consume with a medium-sized boulder of salt.
(Score: 2) by CZB on Friday October 26 2018, @05:20PM (9 children)
I like how at the end of the article the mention a separate nanotube experiment where they made the world's longest so far: 70 cm.
Theoretical advances are great, but manufacturing is where its at.
(Score: 2) by Runaway1956 on Friday October 26 2018, @05:30PM (7 children)
Agreed. Just how manyy 70 cm tubes does it take to reach LEO? Of course, LEO isn't where you need to be, either. The tubes have to reach beyond that, to wherever the counterweight is positioned. That's a helluva lot of 70 cm tubes, placed end to end.
When they can spin a tube miles long, then we can talk. At that point, we can consider just how many parallel tubes it's going to take to bear the weight. 160 tonnes, or 160 tons, isn't even a decent start.
How do you join fibers at the ends, anyway? Superglue? Do we need each individual fiber to reach all the way out to our counterweight? Or, do we weave many boatloads into some kind of mat? Questions, questions, questions - and no one is offering very many answers.
Abortion is the number one killed of children in the United States.
(Score: 2) by Arik on Friday October 26 2018, @06:17PM (5 children)
As far as I understand, you simply don't - not at that level anyway. Once a bunch of strands are together in the form of a rope, you can join the ropes using knots, but doing that at the level of monofilament isn't such a great plan. One of the advantages of synthetic fibres over natural ones is the relative ease of producing extremely long filaments.
If laughter is the best medicine, who are the best doctors?
(Score: 5, Interesting) by Runaway1956 on Friday October 26 2018, @06:31PM (4 children)
With most knots, you lower the breaking point of your rope anyway.
https://scoutpioneering.com/tag/how-much-knots-weaken-rope/ [scoutpioneering.com]
Abortion is the number one killed of children in the United States.
(Score: 2) by Arik on Friday October 26 2018, @09:27PM (3 children)
If laughter is the best medicine, who are the best doctors?
(Score: 0) by Anonymous Coward on Saturday October 27 2018, @01:24AM (2 children)
In composite materials where large parts have to take tension, it's common for fibers to be bonded side-by-side (in shear) with a minimum of the adhesive (epoxy, or other).
Nothing says that the space elevator needs a flexible tether.
(Score: 2) by maxwell demon on Saturday October 27 2018, @06:55AM (1 child)
If it isn't flexible, how do you store it in a launch vehicle in order to get it up to space, in order to start building the space elevator?
The Tao of math: The numbers you can count are not the real numbers.
(Score: 3, Informative) by Runaway1956 on Saturday October 27 2018, @11:56AM
To answer *only* the question you asked: Make the fiber in space, and lower it to the ground. Thus, a rigid fiber cable need never be packed into a launch vehicle. Note that I have not attempted to explain where the materials for the fiber come from, or when or how the fiber fabrication plant came into being.
I suspect though, that the more rigid the elevator is, the more susceptible to damage it would be. It's going to have to flex. The far end, at the counterweight, won't be absolutely motionless, after all. The moon will influence it's orbit, as well as the sun, and to a far lesser degree, each of the nearer planets.
Abortion is the number one killed of children in the United States.
(Score: 2) by HiThere on Saturday October 27 2018, @04:25PM
Perhaps what you need to do is braid the nanotubes with lots of overlap in the bundle. I'm not sure what the inter-nanotube friction would be, though. Still, bundles of braided nanotubes, with each braid several miles long should work. This would need to be tested, of course. If you need to embed the stuff in a matrix you'll impair the strength vs. weight. But perhaps the outside of the nanotubes could have some molecules attached that would create sufficient friction to avoid the need for a matrix.
Javascript is what you use to allow unknown third parties to run software you have no idea about on your computer.
(Score: 2) by ikanreed on Friday October 26 2018, @06:22PM
Yeah, but this team is making bundles of nanotubes. Which, as they note in their paper, are typically far weaker than individual nanotubes due to fragmentation and van der waals interaction, but they've found a way to mitigate that weakness somewhat.
If this technique can be replicated and proven, then scaling it should be a much easier problem than scaling the nanotubes themselves.