Nanostructured metamaterials have shown a lot of promise in what they can do in the lab, but often have fatal stress concentration factors that limit their applications. Researchers have now found a strong, lightweight nanostructured carbon. [via BGR]
Using a multi-objective Bayesian optimization (MBO) algorithm trained on finite element analysis (FEA) datasets to identify the best candidate nanostructures, the researchers then brought the theoretical material to life with 2 photon polymerization (2PP) photolithography. The resulting “carbon nanolattices achieve the compressive strength of carbon steels (180–360 MPa) with the density of Styrofoam (125–215 kg m−3) which exceeds the specific strengths of equivalent low-density materials by over an order of magnitude.”
While you probably shouldn’t start getting investors for your space elevator startup just yet, lighter materials like this are promising for a lot of applications, most notably more conventional aviation where fuel (or energy) prices are a big constraint on operations. As with any lab results, more work is needed until we see this in the real world, but it is nice to know that superalloys and composites aren’t the end of the road for strong and lightweight materials.
We’ve seen AI help identify battery materials already and this seems to be one avenue where generative AI isn’t just about making embarrassing photos or making us less intelligent.
Is it compressive strength needed for a space elevator to become viable or tensile strength?
I believe I remember it being tensile strength with a counter weight being used in a slightly higher orbit than geosynchronous to provide the force needed to keep the cable taut.
you’re right, it’s entirely tensile strength you need for a space elevator in theory. My understanding is that lattice or truss structures are great for stiffness, buckling resistance, and conpressive strength, but that configuration doesn’t really do much for tensile strength. tensile strength pretty much adds, so you prrtty much just bundle a bunch of high strength fibers together to get optimal tensile. i.e. a bundle of aligned carbon fiber or carbon nanotubes or such.
very cool research, but the space elevator example is just the hackaday writer shoehorning a (probably required) article link into the article.
Both would do. But each leads to a different design. Tensile strength is usually thought of for making a kind of a “let’s pull on the rope both side”. Typically, this means that you’d need something that’s pulling the weight of the rope in space, so the tension counterbalance the its weight and the system stays in equilibrium. This seems more feasible than the other design.
In a compressive design scenario, you’re simply building a big tower that must support its own weight. No need to get very tall (like 36 000 km tall for a tensile elevator), you just need to reach high enough to counteract the atmospheric pressure, so you can launch at 11000 kph to the east to reach orbital speed. A compressive structure thus should reach ~80km high, which is currently unfeasible because of the weight it should support at its base and the lateral pressure (wind) it should counter.
100,000% tensile, and it’s doubtful that any material could possibly have strong enough atomic bonds
hey AI, I need a new roof for the shed I store my riding mower in, chop chop!
Did AI really find it, or is it just the fact that we can run simulations and speculative solutions millions of times faster and pick out the likely candidates more quickly?
A real AI might just want to play golf, or kick back by the pool, instead of being forced to work on problems that only affect meatbags.
TIL I’m actually an AI.
Yeah, I thought the same thing. This reads more like the algorithmic optimisation strategies I learnt about at university. I did learn about them alongside “AI” ideas, but it was very clearly not AI.
AI in the industry use of calling any machine learning algorithm AI. There still aren’t any generalized artificial intelligences (as far a I know?).
Man I would like to kick back by the pool instead of work on problems that only affect meatbags as well… Yet here I am
Honestly, it’s debatable if this is “AI” at all. Not just in the sense that it’s not using neural networks, but in that this kind of optimization I don’t think has EVER been called “intelligent.”
All it’s doing is a brute-force search through various possibilities, until it finds the one with the best score. No learning from previous iterations to guide the search or anything like that.
This should make a very nice buoyancy material for deep seas :D
Block of tofu
something doesn’t quite seem to pass the sniff test, surely there is a step missing – they make a carbon micro lattice but on a resin 3d printer – surely they would have to carbonize it somehow, like heating the ever living hell out of it in a vacuum?
Probably one of those things that is really neat but will just be really hard to scale.
2PP is a little different from normal lithographic resin printing. It’s like comparing a steam engine to an internal combustion engine. As for the carbon, you can pyrolyze nearly pure carbon with 2PP.
https://www.sciencedirect.com/science/article/abs/pii/S0008622322007400
Looks like they’re not doing direct pyrolization here if you check this figure from the paper. They’re building it first then doing pyrolysis afterward at 900˚C for 5h under Nitrogen. Probably could in future work though?
https://advanced.onlinelibrary.wiley.com/cms/asset/50b95379-a1c9-4643-b787-f1345098a208/adma202410651-fig-0001-m.jpg
I guess I’m not seeing direct pyrolysis in the snippets of the paper you shared. It looks like they were just optimizing things in the precursor before cooking it, but it’s not entirely clear. Seems similar to the production of xerogels and aerogels other than the precursor being produced via 2PP instead of a more conventional method?
I’ll admit they’re not fabrication techniques I’m super familiar with since I did more tape casting and spin coating of ceramics.
How difficult is it to synthesize? Will it scale(size-wise)? And what of other properties like brittleness, thermal conductivity, tension, torsion, wear resistance, hydroscopic infiltration, etc? Does it have chirality or directional properties like other carbon-based structural materials? Not much good as a structural material if it acts like a leaky sponge that crumbles when touched, despite having other extraordinary properties… (like poorly-made concrete). Would it benefit from elemental inclusions like metallic or silicate doping?
If it has poor thermal conductivity, with the strength and weight, it would be a good candidate for spacecraft tiling.