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‘99.99 percent air’: Boeing releases video of revolutionary lightweight metal (rt.com)
245 points by signa11 on Oct 12, 2015 | hide | past | web | favorite | 91 comments

The headline "Boeing releases ...." led me to believe that this research had been done at Boeing. Is my assumption unreasonable or is the reporting disingenuous?

The work was done at HRL, which Boeing owns a large part of (source: I worked at HRL).

Also, from my understanding, the most interesting thing about this material isn't the weight but the manufacturing process. To build the lattice they used a specialized 3D printer which combines the beams from a few directions, cf https://en.m.wikipedia.org/wiki/Metallic_microlattice

HRL is jointly owned by Boeing, Raytheon and General Motors. The parent companies commit to spending a certain amount on research every year, and researchers compete internally for those funds. This must have been a Boeing-funded project.

That unlikely ownership is an historical accident: those megacorps each acquired pieces of Hughes Aircraft, which built Hughes Research Labs, now HRL.

Maybe this is what she was getting at when making the comparison to bone structures, but from seeing how it deforms under load in the video, it seems that to realise its potential for serious structural applications this needs to be bonded between two sheets of material to form a composite structure that works like a 'space frame'.[0]

This would allow the fabrication of large stiff arbitrarily shaped panels to form monocoque structures. I would imagine that you could even replace large parts of the conventional rib and skin structure of an aircraft with this eventually. The trickiest problem will be transmitting loads through panel joints.


Also it would be be cool if the density of the lattice could be varied. Bone structure is a great example of this, it's a 3D Voroni diagram where areas of smaller cells are indicative of stress concentrations.

I'm still failing to see how this material would provide strength. In a composite structure like you suggested, the two sheets could still crush the microlattice on the inside.

It doesn't seem stronger than foam during compression, so the fact that it returns to its original shape seem pointless. What am I not seeing?

I agree completely. Without knowing the spring constant it is tough to say. Although, if they could increase it using thicker tubes it could have applications as shock absorbers in landing gear. I would not be too surprised if they just went as light as they could for the press release. In the end, without a list of mechanical properties it is impossible to say. On the other hand, it could be completely useless and they just wanted to get some good PR out of a failed idea.

I think the egg-drop challenge example is terrible. If the egg + protection impacts the ground at a fixed velocity, the most relevant factor is the /distance/ the egg moves before coming to a stop. So if it requires "three feet of bubblewrap" (nonsense number, per the video), then it will also require three feet of microlattice, unless the microlattice applies a more constant force on the egg as it compresses.

Bad examples like that make it difficult for me to trust such videos.

A secret of the egg drop is actually that the egg doesn't really need much cushion to spread the impact over time. If you can spread the pressure evenly and hold it still, you can get away with quite a small crumple zone.

Carve a perfectly egg-shaped hole into a pair of styrofoam bricks, then tape them together with the egg inside. You'll beat 99% of the other kids who were trying to protect their egg with soft materials.

Source: I tried using wet sponges and carpet underlay, but was soundly beaten by a kid who carved a hole in a pair of styrofoam bricks.

I won my physics class egg drop challenge and three years of California MESA competitions in high school using spray insulation foam to make molds of specific eggs.

The MESA rules were 14" diameter max, no liquids, no parachutes, dropped from 60'. I cut a pattern of holes in cardboard and sprayed the foam over the eggs (lubricated with PAM), pulled the cardboard off, lubed them up on that side, and sprayed the other side. I trimmed the whole container to a sphere a little over 14" diameter and then compressed it as much as I could (Literally having someone stand on top of it) and wrapped it tightly in tape.

My best record using this method was 32 eggs with 100% survival.

We had a egg toss challenge. And were handily beaten by the group that duct-taped their egg inside a Nerf™ football and thrown by their team's quarterback. It was the uniform support of the shell by the Nerf material that did it.

With my first kid we used a small coontainer filled with a non-newtonian fluid. Worked like a charm. The following year we went for a paper cone with impeller blades fabricated along the top edge to make it spin and slow it down a bit.

What about suspending the egg in a jar of water?

I dropped an egg in a shoe box full of sand and it worked fine. Unfortunately, that design wasn't allowed at my school.

Water doesn't compress as far as I know, so it would be like the egg hitting concrete...

water also distributes pressure uniformly, so it will be like trying to crush the egg pressing all the surface points of it with the same force. Which is not easy to do.

I once did the egg drop with a plastic container of honey. The container shattered and got honey everywhere, but the egg survived.

We should do this for egg drops on the moon. One time containers filled with honey.

So it is a good idea?

It's still a fluid though, so applying a force doesn't necessarily compress it. Think about dropping an egg into water.

I wonder if you could convert all the deceleration into compression using water though.

Same principle - putting egg in a plastic jar of peanut butter works too. Provided the plastic jar is lightly padded. It takes a lot less padding to project the plastic jar than a naked egg and the viscosity of the peanut butter means that the egg won't drift from the center of jar.

I thought the canonical solution was also the cone-onical solution har har har.


Just did some back of the envelope Wolfram Alpha calculations, and it seems to me that the Eiffel Tower is about 99.999% air. Does that constitute an even lighter material?

Edit - Just trying to understand the moral distinction between a light 'material' and a light 'structure' here. This seems more like a structure to me?

It's all about the scale. Grossly speaking, on an average, Eiffel Tower is perhaps 99.999% air. But is this true at every scale? Does every cubic meter of the Eiffel Tower have 99.999% air? Or does every cubic micrometer? If we were to build a megastructure of size 1,000,000s X Eiffel-size with Eiffels as the building blocks being replicated, then perhaps the Boeing material is not super-useful. But most applications are 1,000,000s X the Boeing lattice sized.

So it's very light, and it's very elastic. It's also not at all rigid. What would you use it for?

As another top-level comment mentioned, depending on the sheer strength, it could be used in composite structures.

Take a 2'x2' 1" thick piece of foam. Laminate some fiberglass onto both sides of it. This is basically how modern boat hulls are constructed. Extremely light, rigid, insulated and durable.

WAG, but if it would allow you to replace 1 ton of foam on a 40' yacht, that's one ton of extra cargo/amenities you could carry instead and maintain the same water line. Or alternatively you could produce a faster boat with less wetted area.

I'm sure a real engineer has a better idea of practical applications. But I like cruising yachts so. :-)

1 ton of foam? Foam used in boating is usually in the 2-4lb range, which means 2-4lb per cubic foot. There's not much chance a 40' yacht has 1000 cubic ft of foam in it - far more likely it's got 20-30 cu ft, which is under 100lbs of foam. Not enough to move the needle a bit.

Plus, foam provides displacement in case of breaches as a matter of it's nature. This lattice wouldn't provide any displacement, so a small breach would mean you're 2" thick composite hull would fill with water, which would be bad.

Just by looking at it, I doubt there is enough shear strength to make it a useful sandwich panel web. Then again, I've been wrong before. But metallic/composite honeycomb is pretty well optimized stuff as it is.

A bicycle helmet made out of this material sounds perfect to me. Good protection, light weight, and great ventilation.

Doesn't seem a good protection against your head hitting a sharp edge - due to its elasticity.

Well you'd still pair it with a shell.

Even so, I don't see how this could replace the foam in a conventional helmet. It seems like it has its strength in its elasticity, but not much else. The video did a poor job at explaining good applications.

Wings. One fairly recent experimental plane [1] used aeroelasticity to control a plane instead of the normal surfaces. A wing made out of a material that can flex and bend would be able to much better take advantage of this effect.

[1] https://en.wikipedia.org/wiki/Boeing_X-53_Active_Aeroelastic...

Crash helmets? (a layer inside, not the whole thing, obviously..)

Beds. I can imagine this would be awesome as a bedspring. Or on planes, seats.

yeah from the way it compress and bends I's hard to see how it's going to replace structural elements as the video implies.

maybe fuel tanks shells? having the tank collapse as it's used instead of being filled with vapors would also reduce flammability in general.

Motorcycle fairings

I wonder how flamable this is? Metal dust and shavings have a tendency to go FWOOSH! and burn really hot and fast; I imagine this would be the same, no?

It's okay: they're going to make the micro-latice out of aluminum and iron oxide. And fill the interior with hydrogen because it's lighter and cheaper than helium. /deadpan

Imagine if it was put in a plane and the plane caught on fire. The whole plane just goes FWOOSH and disappears completely. Well, atleast you get to skydive before you die.

>atleast you get to skydive before you die.

But, you're on fire!

The 500 mph wind should put it out soon!

hows she gonna say her material would crush the egg drop challenge and then not actually do it? Wasn't that the whole point of it in school?

Also the perpetual winner for egg drop challenge is jello with uncooked rice mixed.

As namechecked in the article. One of the differences is Aerogel "have random cellular structure, so they are less energy absorptive and strong."

Am I the only one annoyed by videos with very short cuts that barely let you see the properties of the material?

I felt that this video was particularly bad; not only did they stitch together very short video clips, but they also stitched together short audio clips to form sentences. It makes me feel like they could be making the lady say something completely different than what she was actually saying, even though I know this probably isn't the case. See 0:41 for an example: https://youtu.be/k6N_4jGJADY?t=41 ("so they... <obnoxious cut> aren't easily crushed.")

It's more likely that the cuts were to remove umms, ahhs, and digressions.

Yeah kinda bizarre. Do another take.

what a terrible video ! the sound cuts everywhere make the whole thing sound like a political parody where you stitch together words from different meetings... Seriously, Boeing, you couldn't afford more than a single shot on this. Or actors, or something ?

"It's really exciting to work with things that we make that eventually go into real product that lots of people use". It's sad on so many accounts bu it sounds like a political debate to me. might as well say "It's cool to do stuff with some stuff that could be used to create stuff for people to to stuff with", and it's going to cointain just as much info.

This is neat stuff yet I am having trouble with the use of the term "material", somebody help me.

To me this isn't a new material any more than aluminum honeycomb is a new material. The material is aluminum or steel. They are then fabricated into honeycomb sheets or lattices.

I don't see it as discovering a new material but rather fabricating an existing material in a different way.

Other examples of this might be aluminum truss used in staging and the use of trussed steel in bridge building.

What is a material?

Does it help if you think of it as an alloy of metal and air?

When you make steel all you are doing is forming various crystal structures, and grains. Martensite, Ferrite Austenite, Cementite, etc. They are all the "same" material (iron and oxygen and carbon), yet if you figure out a new way of arranging their shapes "just so" you can say you invented a new type of steel.

This is the same way - they figured out a new way of arranging the atoms, so it's a more or less a new material.

(I do see your point of course, and this is more macroscopic than grains in steel, but I think it's not unreasonable to call it a new material.)

Thanks for all the input. I think I found something to quiet my mind:

Raw Material vs. Fabricated Material.

To me this distinction makes the universe come back into alignment. Honeycomb Aluminum is a fabricated material made from aluminum. Denim, a fabricated material made from cotton. A lighting truss, fabricated material from aluminum. The microlattice product from the article is a fabricated material from steel.

Works for me.


You don't need to be so literal. When you look at honeycomb, for example, the manufacturers provide strength data in much the same way you'd see it for a solid metal. When you model it with finite element software, you treat it as an monolithic material - you don't model every fold of metal. In that sense, honeycomb (and this stuff) is a material in that it's used the same way. The properties of the "material" already account for its micro-structure.

Material includes the characteristics that the given shape/configuration provides. For example, denim and gingham are both made of woven cotton. However, they're different materials due to their differences in properties -- gingham's light and airy and loosely woven, while denim is rugged and more tightly woven. Composition is just half of what makes a material a material.

When I Google around, it seems that sites explaining what aluminum honeycomb is pretty consistently follow the pattern "Aluminum honeycomb is a [adjectives] material with [characteristics]."

I get what you're saying about trussed steel, but I think that's really just getting at the point that categorical distinctions are rarely cut-and-dry.

This will be awesome for airships.

Fill it with hydrogen and seal it.

Putting problems with containing hydrogen aside, it seems this would actually work. A structure made with 99.99% hydrogen (0.09 kg/m3) and 0.01% aluminum (2700 kg/m3) by volume would have an average density of 0.36 kg/m3. This is lower than air (1.29 kg/m3) and bit more than twice the density of helium.

if you need to seal it, might as well not use anything in between, right?

Why not remove everything and go for vacuum spheres... https://en.wikipedia.org/wiki/Francesco_Lana_de_Terzi#Airshi...

Unfortunately the resulting air pressure difference crushes the structure which is what makes vacuum spheres impractical as well.

Wrapping it with carbon fiber and filling it with Hydrogen seems like a better option.

It depends. This is the first material I have heard of that would allow you to have structural elements lighter than air. Just an empty envelope is not very rigid.

The most stable airship would be with a floating foam. Even if some part of it is damaged - the rest will float.

A foam structure could yield lower release speed in case of puncture, and possibly prevent explosive fire propagation in hydrogen, thus allowing its safe use in airships (modern "cold air" airships use the rarer and more expensive helium instead)

Yes. The only reason I can think of that you would do this is to build some kind of hybrid airship that generated some lift from wings to increase MTOW (lifting capacity) but still has all the energy efficiency of low speed and therefore low drag.

So did they actually do the egg eggsperiment with this micro lattice material?

Hmm.. That let me think.. "Eggsperiment"!

Is the metal light or just the structure?

It's the structure. This claim is easy to beat. I have a wrench here on my desk and taking the wrench and the house as the system, it's 99.999% air. Boom!

There's nothing interesting here except the manufacturing process used to make such a thing.

If you built a scale model of a good egg drop rig for the size of a person would it protect them from jumping off a building without breaking anything?

Here's a med student's two cents: I doubt it simply because you can't realistically prevent deceleration injury to the internal organs.

With an egg drop, you pretty much just have to worry about the integrity of the shell, but with a person there are a lot more factors at play. The first example I can think of off the top of my head is in MVAs. Modern cars are designed to absorb a lot of the momentum from collisions and minimize injury to passengers, but that isn't always enough to save lives.

You're not a solid body. You are basically a big blob of salt water that happens to contain some hard bones and ligaments mixed in with vulnerable organs. Even if you can protect the blob, those organs can still move around inside it.

Let's say you slam into another car head-on. The frame of your car absorbs a good bit of the energy, but your body still "wants" to keep going forward. Then your seat belt stops your thorax, but your heart and major vessels keep going and slam into your ribs, sternum, etc. Best case scenario, you'll walk away with a minor myocardial contusion and possibly develop a dysrhythmia, but if you're not so lucky, your descending aorta may actually be ripped by your ligamentum arteriosum and you'll mostly likely bleed out.

Your head isn't as restrained as your thorax in a car, but even if it were your brain can still move around and slam into your skull (which can lead to traumatic brain injuries like concussion, diffuse axonal injury, cerebral laceration, etc.).

Thanks, that was informative.

It would need to be fairly ridiculously sized. Far easier to just cushion the ground and have the 'rig' waiting at the impact site. e.g. skydiving into a bunch of cardboard boxes with no parachute. https://www.youtube.com/watch?v=jLDSg8B4Cxo

Mythbusters tried this, wrapping a person in bubblewrap, and could drop Adam from 15 ft. But the limit they hit was that the weight of the bubblewrap they were putting around him was becoming uncomfortably high.

Part of the reason why you can't just take the egg result and scale it up is called the square-cube-law.

Check out these guys: http://ntopology.com/index.html/

They make some awesome software that let's you create wither flat or volumetric lattice structures from existing 3D models.

Do not forget about Aerographite https://en.wikipedia.org/wiki/Aerographite (only ~180g/m3, much lower than a topicthing - 0.9kg/m3)

So is the material itself 99.99% air, or just the net structure?

If you take the convex hull of a piece of this material, the volume is occupied by mostly air, same as for aerogel, foam and the like.

The structure. A thing to note is that the tubes themselves are hollow, a very slim metal cylinder.

"each strut is about 100 micrometres in diameter, with a wall 100 nanometres thick"

- https://en.wikipedia.org/wiki/Metallic_microlattice

"100 times lighter than Styrofoam." What? “thickness 1,000 times thinner than a human hair.” Huh?

I sense an alternation between pop and technical language, i.e. "lighter" and "denser," and “thickness and “thinner.”

It looks like we are looking at a composite material here. Scales, densities, and thermodynamics typical to the nano world do not easily apply to the STP world where 25C and 1Bar reign king.

Since the microcosm denizen is a tube, what are median wall thicknesses and tube diameters?

Did the redacter here also work for Apple to measure their new products as “thin?” If so, they may qualify to be an Apple genius.

By volume or mass?

Yeah, wouldn't an empty soda can be 99+% air by volume?

Surprisingly no, google claims cans have been getting lighter but 15 grams empty is realistic, lets assume water at a gram per mL, 12 oz water is about 350 grams, that is about 5%, I don't remember the exact specific gravity of aluminum but its less than 3 (not a very dense metal...) so 5/3% by volume, roughly? This is all engineering estimates done in my head so exact numbers will be different but its not going to be orders of magnitude off.

A significant source of error beyond 1 sig fig is going to be the weight of ink/paint and the weight of the pop tab on the top. Also cans are not filled 100% with liquid, so there is air space (it has 12 ounces of liquid, but its a 12.something volume tank)

Something interesting to think about is fluid dynamics, a foam like this would stop sloshing at almost no weight penalty. If you like the idea of tin foil thickness gas and water tanks, then this would seem to be a requirement for that technology.

Well, the volume of a regular aluminum soda can is 375 cm^3 [1]. A modern can is about 15 grams of aluminum.[2] Just a really quick plugging it into Wolfram Alpha, the volume of 15 grams of aluminum is about 5.6 cm^3. [3]

So, that's about 1.5% aluminum by volume. So a soda can is about 98.5% air by volume.

[1]: http://jwilson.coe.uga.edu/emt668/emat6680.folders/howard/vo...

[2]: http://aluminium.org.au/FAQRetrieve.aspx?ID=45688

[3] : http://www.wolframalpha.com/input/?i=15+grams+of+aluminum+to...

> a foam like this would stop sloshing at almost no weight penalty

So would filling your gas tank with sponges; however, with that much surface area exposed to the liquid, I suspect it would be really hard to get the majority of the liquid back out.

Russia Today on Hacker News? Really?

So what? The topic is non-political, and even if it were, you are free to skip it.

I personally like seeing non-mainstream or controversial topics on HN, even if I don't agree with them.

HN's focus is on the content. If the content is good, it doesn't much matter what the source is.


Future MacBook?

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