Mr McGuire: I just want to say one word to you. Just one word.Benjamin: Yes, sir.Mr McGuire: Are you listening?Benjamin: Yes, I am.Mr McGuire: Plastics.
You may recognize the above dialog from the movie “The Graduate” starring a young [Dustin Hoffman], whose character is getting advice about what line of work he should get into after university. Maybe Mr McGuire’s advice should have been “Microlattice.”
If you take a step back for a moment and survey the state of materials, you’ll see that not much has changed in the last 50 years. We’re still building homes out of dead trees, and most cars are still made out of iron(although that is starting to change.) It’s only been just recently has there been advances in batteries technology – and that only came about with the force of a trillion-dollar mobile phone industry behind it. So we’re excited by any new advance we see, and Boeing’s new “Microlattice” tickles our fancy.
Boeing isn’t giving away the recipe just yet, but here is what we know: it’s 99.99% empty space, making it extremely light. It’s so light, that if you drop it, it floats to the ground. It’s also compressible, giving it the ability to absorb energy and spring back (you can see it in action in the after the break.) It’s made by creating a sacrificial skeletal structure the shape of the final lattice, then coating that template with nickel-phosphorus alloy. The temporary inner structure is then etched away, leaving a “microlattice” of tiny interconnected hollow rods with wall thickness of about 100 nanometers. Of course it doesn’t take a rocket surgeon to figure out why Boeing is interested in such materials, they are eye it as an extremely lightweight building material for planes and spacecraft.
But…it’s squishy. Very neat, but usually metals are selected for structural applications precisely because they’re _not_ squishy…
that comes down to geometry choice. the sample material’s geometry was probably designed around compressibility
The geometry choice is what fundamentally makes this light. So it’s a trade off.
Yeah but instead of a diamond shape, you could build it into something with crosslinks, based on triangles maybe, which aren’t compressible. Most of the weight saving in this isn’t because of the geometry, it’s because it’s a hollow structure, made of hollow rods.
It would likely be skinned with a rigid metal to form a structure similar to the bones shown in the video. Some aircraft are already built that way, but the hollowed core is made of aluminum “honeycomb” sheets underneath solid aluminum sheets. The honeycomb aluminum is “rigid” in the plane normal to the solid aluminum sheet, which is beneficial. But, this new stuff doesn’t appear to be rigid in any particular direction…
I was under the impression that the core typically is made of Nomex or some other material that can be partially bonded into layers, then pulled apart to into a honeycomb. Other common skin materials I’ve seen are fabrics woven from polymers like Spectra, Kevlar, carbon fiber or fiberglass.
Have you ever heard of fiberglass over foam? You use a soft foam inner with a rigid outer shell. The soft inside adds a bit of give and the hard shell holds the shape. Its basically the same structure as a birds bones. Its used in boat-building and custom cars all the time. Pound for pound it’s a stronger material than steel.
My question is why they are so worried about it being made of metal. At this scale, may types of plastics are actually much better than metals, with better properties. Flexibility, elongation, and resistance to stress cracking would all be better handled by a material such as UHMW HDPE. I suppose the problem is in creating the structure with current production techniques.
How do I put two pieces together? Weld, rivet, sew?
if nickel-phosphorous will Wet with solder, then you could do that. it might take sewing nicely – but that depends on the strength of single strands and could be a weak point. welding might not work well, the structure probably can’t take much heating. so you’d likely have it made with attachment ‘baked in’, one possibility being to grow it on a compatible metal plate.
I doubt you’d get it “by the foot” the way you do fabric or solid sheet material – more likely you’d order it the same way you slice a model for 3D printing – a solid shell (or anchor points), then you choose your infill pattern and density
I’ll bet you could join it with staple sheets, something that would overlap both pieces and have teeth that would poke through and grip the latice.
You’ve pretty much described Velcro (hook and loop). Where the microlattice has the loops and the fastening material has many flexible hooks.
As in your example, you could butt two microlattice structures up against each other and lay a hook strip across them, or you could sandwich a single sheet of double sided hooks between them.
Electrodeposition with only the surfaces to join being uncoated could be one option, then the insulating coating would be removed in a final step, but I expect the entire part is created in one pass, skinned (given a shell) and the shells are bonded into large assemblies. Just a guess HIHNI what they really plan to do.
Honeycomb panels usually use a pre-preg glue, I don’t see why that wouldn’t work for this. Build core, apply pre-preg, apply skin, vacuum bag, bake until ready.
Can’t wait until the car’s skin is made of this. No more $3500 repair bill because someone texted and didn’t see me stopped. The dented fender will pop back normal.
Yeah, but today fenders are made this way so that you must replace whole part even after small bump.
WAKE UP SHEEPLE! Really? pressed steel fenders are a conspiracy to make you spend money on repairs???
Small bumps can be banged out, in fact it’s only vanity making anyone “fix” cosmetic damage to a vehicle. Try banging a dent out of carbon fibre or GRP or any other material. Even aluminium is a bit of a pain as it stretches and fractures.
Steel is a frickin’ amazing material, and making stuff out of anything else is both difficult and expensive and likely to perform worse. Plenty of cars have large swathes of plastic, even plastic fenders (my car has them), but that shit will only bounce so far before it shatters/splits and then you can’t bang it out, you’ve got to bin it and buy a new one just like steel.
Your repair bill would likely be more like $35,000 instead.
Your bumper can absorb more energy by deforming plastically (permanently) than it could by deforming elastically (spring-like).
As a result, you don’t actually want a bumper made purely of this stuff.
That might be true but is there an general reason that materials deforming permanently can absorb more energy? Logically an elastic material should be able to give the exact same compression characteristic. Only if the next car isn’t crashing into you while you crash into something, those materials would immediately want to return to the original form which would cause the G force on your body to last twice as long.
I guess the permanent deformation requires kinetic energy to be converted into chemical energy, and be lost as heat.
What’s going to hurt more – hitting something and stopping (energy absorbed & dissipated) or hitting something then bouncing backwards with nearly as much force?
You may be trading a less expensive automobile repair bill for a more expensive hum repair bill assuming the a live human left in need of repairs. All the energy initially absorbed will be released. The reason my protective head buckets, dash pads etc. are made of foam the deforms not cushions.
Maybe a microscopic 3D printer that could print bubbles of air starting with small bubbles near the outer surface, say 0.5mm and increasing in size the further away from the outer surface that you are say 30 mm. It could produce some very strong structures.
Couldn’t you just spray plastic foam onto a mould. with an adjustable amount of air in the foam? Denser at the surface, and dial in more air as you fill.
I wonder if the air you we pumping in could be some sort of gas that acts as an epoxy hardener.
I’m not sure if it’s really the lightest, I’ve seen some metal foams that make similar claims, and have similar properties. But it’s still impressive.
The problem with exotic materials like these is that manufacturing process is so complex and expensive, the product is too expensive to use by anyone short of NASA. And it’s unlikely to come down in any reasonable time frame. How long have aerogels been around now? I just Googled a price, $90 for a 2″ x 3″ x 0.3″ block. At that price I figure I can insulate a small Igloo chest with it for about $50K. It might as well not exist.
Now show me a process to make this cheap enough that it can find real-world uses in consumer products, and I’ll get excited. But I’m not holding my breath.
Aerogel chunks are 375 USD for 5 gallons on Nuclear United : https://unitednuclear.com/index.php?main_page=product_info&cPath=16_17_69&products_id=89
2 mm diameter grains. not chunks. useless.
Hardly useless. They work really well.
isn’t it weird to call it “metal”, when the special part is the structure?
naaa its fine
in other news I invented LIGHTEST WATER EVER!!!11
https://shellesplayschool.files.wordpress.com/2011/10/soap_bubbles_rgb.png
Don’t think so big. Air-bugs. not airplane. Integrated airframe and powerplant. 3d printed.
Great article. Needs an edit. Sorry for pointing it out.
IM SEEING BALLS!!!
“Not much has changed in 50 years”?
Hephaestus’s sweaty nuts, man.. the past fifty years have done to materials science pretty much the same thing they’ve done to electronics (a tightly interrelated field). We still build houses from wood because wood is still a lightweight and easily worked material with excellent compressive strength. We still make cars out of steel because it still has a higher specific strength and better thermal performance than any cost-competitive alternative.
Relevant fun fact: there are about 130 different kinds of ‘steel’ in a car these days.. all engineered for specific purposes and not interchangeable.
Don’t get me started on the light metals: https://en.wikipedia.org/w/index.php?title=File:Aluminium_-_world_production_trend.svg&lang=en
Titanium. Tungsten. The hardmetals. Engineered ceramics.
Thick film technologies, thin film technologies, most of solid-state physics and the entire field of surface physics, Rare-earth magnetics, and a whole category of electric motors that wouldn’t be useful without them. Liquid crystals, which have gone from nonexistent to the dominant form of display technology in the less than 50 years.
Those are just the pedestrian things you don’t bother to notice walking down the street.
Carbon fiber. Graphene. Fullerenes. Quantum dots. MEMS.. we can carve a gyroscope so small that you can’t see it without a microscope and can make it so cheap that it’s a minor feature of your cell phone. DNA sequencing.. we can design and build proteins at the molecular level and in bulk.
I know you just needed a lead, but that particular one doesn’t stand up to scrutiny.
+1… very nice overview of what has changed recently. It is easy to forget!
+1, give this man a column!
Slight correction – USA likes to use dead trees for cheap homes.
The other part of the civilized world tends to use autoclaved aerated concrete (AAC) when price is important.
It’s is veeeery slowly gaining popularity in the US, but has been in use in Europe for nearly 70 years now…
That’s because trees grow well in the US, and are an infinitely renewable and inexpensive resource, and properly cared for it can last for literally hundreds of years (I grew up in a house built in 1811 which was itself built out of a home constructed in the late 1700s, square nails and all). There’s nothing wrong whatsoever with using wood as a construction material.
True, but most American wooden house will absolutely not last hundreds of years as they’re designed to as cheap as legally possible. A drastically superior solution is rammed earth construction, the materials for which are locally available almost everywhere and can cheaply be built to last for centuries. If only the building codes even considered earth as a building material.
Well civilization as we know it will have been wiped out before the planet creates the raw materials use in concreate when the current supply is consumed. the natural gas that heats th rock to manufacture Porland cement. The iron ore used to reinforce the concret structure. Not to mention res recycle the fixed amount of water, concrete consumes that water Concrete and dead trees have the usefulness, but trees should be around until the end days , and they are mankind will get what mankind deserves.
Wood is extremely cheap and plentiful in the US, and as a building material it’s got some exceptional compressive strength and some very light weight. Not only that, but wood deals better with fatigue, making it actually better in situations like earthquakes than steel. Wood support structures for concrete start to encounter damage at the same amount of force as steel support structures and the wood deforms less than the steel. In earthquakes, wood withstands more force than steel before structural failure. It absorbs vibration better and doesn’t work harden from repeated flexing.
Wood lasts better in long term stress applications, take similar forces to steel deformation to deform it, it handles vibration better, it weighs less, and it’s both cheap and easily renewable, and you can get large quantities of it as a byproduct of required forest management. That also ignores the simply massive amount of other products that are derived from wood, from press logs of sawdust that would otherwise be wasted for use as home heating to pharmaceuticals to even rayon.
The city I officially live in is full of houses in effectively flawless condition built of wood back in 1840’s to 1850’s.
I live further out from the city proper, and I could walk into my backyard, cut down enough oak trees to make a modestly sized house and still have enough of a forest around that nobody would really spot the difference.
It’s a strange attitude that seems to be popping up, both the “it’s older fashioned and this other method is much newer and therefore better in all applications and should be used exclusively” along with “Europe does it, so it’s automatically better and everyone else should do it”.
Go check some civil engineering, people use wood where it’s the best answer and concrete where that’s the best answer, same for every other material.
if you are surrounded by trees then you’re unlikely to build a brick house (visit Finland, Germany, etc.) but that doesn’t hold true for everyone. Sweeping generalisations are never correct.
maybe that could eliminate the fire hazards of the lithium batteries because if the total weight of the plane could be brought down to below what the 787 dreamliner is then they could go back to using lead acid batteries and the total weight would still be less than the dream liner.
or if the dream liner could change to lifepo4 batteries or limno2 batteries it would be safer
I do not really understand the hype about it. The original work is from 2011 Schaedler et al, DOI: 10.1126/science.1211649 (read it here: http://kni.caltech.edu/news/greer-science-2011.pdf) no further advance is shown, if it could be large scale 3d printed would be nice, but as the hollow structures are achieved by chemical resolving of the plastic pre-structure, that may not work well for large structures.
Cheers.
Orgiginal work Schaedler et al DOI: 10.1126/science.1211649 (pdf here http://kni.caltech.edu/news/greer-science-2011.pdf), no further advances shown. Same plot as 4 years ago. Cheers.
I don’t know how I feel about calling this a material. Where do we draw the line what’s a material vs whats a structure? Burj Khalifa is officially the tallest material in the world! It’s a giant macromaterial made out of a steel and concrete lattice.
obviously we should not look to you to draw the line.
A material is a thing you make stuff out of, but isn’t useful for anything by itself. A material comes in a measured quantity, it’s not counted individually.
It’s interesting how this material is made though. By shining UV light through a mask into a bath of resin at the angles they want the lattice to grow
Probably easily reproducible at the DIY level.
> it’s 99.99% empty space
So? Your granddad’s iron rod is more than 99.99% empty space.
So this is 99.999999% empty space.
Very similar to other hollow nanoframeworks.
Of course the metal used to make this sort of structural component if the same metal was used to make tubing sheet goods etc.. As the video indicates this is mimicking what is found in nature(bone) does that mean this material may not patentable even the construction process they use may be.
Nah, you’re allowed to rip off nature all you like, it’s only when someone notices it that it becomes patentable. Indeed there’s controversy over drug companies patenting chemicals found naturally in plants, in jungles and rainforests. The company just discovers it, and patents it’s use for a particular thing. They’re also currently allowed to patent genes, including naturally-occurring ones, including from humans.
They blur the line between inventing something, the idea of patents, and finding a use for something that already existed. Not quite in the spirit, some people think.
I see a lot of comments on this, but nobody seems to be hitting the mark I see.
It looks to me like this could be EASILY reproduced with a 3D printer, using either a conductive filament(?) or conductivity modified plastic (search HaD for graphite painting 3D prints), electroplating, and then solvent dissolution of the underlying structure.?
I’d try it, but I don’t have my 3D printer yet. I’m thinking a carbon (graphite?) filled, HDPE modified paraffin filament, for easier removal.
Any thoughts, or someone willing to give it a go?