Scientists Develop Thermal Camouflage That Can Dupe Infrared Cameras (cosmosmagazine.com)

Writing in the journal Nano Letters, scientists from Turkey, the U.S. and U.K. describe a material that acts as thermal camouflage. Cosmos reports: Coskun Kocabas and colleagues created a film comprising multiple ultra-thin layers of graphene and a bottom layer of gold, with non-volatile ionic liquid in between them. When a small current is applied, the ions move up into the graphene layer, cutting down the infrared radiation the surface would normally emit. Because it's thin, light and flexible the film can be applied to any number of surfaces, including clothing. Tests have successfully camouflaged a hand owned by a subject wearing a covering of the material, and others have shown it to be indistinguishable from its surroundings in a variety of ambient temperatures.

Comments

Where does it go?

[Anonymous Coward]

You radiate IR for some very good reason. If you are wearing a suit of this stuff I imagine you won't be wearing it a long time.

Re:Where does it go?

[Meneth]

The article doesn't say, but I suspect the material changes the frequency of the emitted radiation, not the effect. So if the frequency goes down, the amount would have to go up.

Re:Where does it go?

[Smidge204]

Nah, it increases the wavelength. You become invisible to thermal imaging cameras but you glow like a lightbulb. ...the technology isn't quite perfected yet.
=Smidge=

Re:Where does it go?

[sysstemlord]

In this case, it decreases the wavelength, or increases the frequency.

Re:Where does it go?

[jellomizer]

Like decreasing the wavelength into the microwave? Or you become a radio broadcast? Boost it up so you are emitting Gamma Rays.
To the main point, where does that energy go? Perhaps it will take the body heat and turn it into electricity to power your phones.

Re:Where does it go?

[AHuxley]

The air around the user as not a hot spot of a heated human on the move/standing still that most computer guided detectors expect to find.
When the devices are set to scan vast areas, that is human shape has to be expected and well documented. So the human using the detection is not needed to respond to every slight change in heat over hours and hours.
That sets a detection level to an expected "hot" human, moving, not moving, trying to hide, using a blanket. Everything that is expected and calculated for.
Move the heat is a different way around the human, and not in the shape of human and the computer supported detection system might just not alert.
The "AI' only knows about all the hot humans it has seen. Not very different shapes that are not as hot as human.
The computer system human use have to have a hot human walking, running, sitting to show up. The heat is still moving, just not in the big bight look at me pattern expected over the past decade.

Re:Where does it go?

[careysub]

The summary and the article abstract do no make this clear but what that this device does is change the emissivity of the surface in the thermal IR band, which is around 10 microns. This means it simply alters the thermal emission - it makes is "white" or "black" (or shades of grey) in the IR band, which is far below normal optical bands, to match whatever the emission of the background is.

The optical band appearance of an object tells you nothing about its thermal IR band appearance. Two common materials that are pitch black in the thermal IR band: pure water and regular glass. Clean polished metal surfaces are reflective in both, but if it was could covered with an IR band black paint, and you would be none the wiser visually.

What effect would it have on body temperature regulation? Thermal radiation is only one of three ways your body disposes of metabolic heat under normal circumstances - the other two are convection and evaporation (which also works with convection but is a separate mechanism). The first two (radiation, convection) work both ways - you can gain heat, not lose it in a hot environment. There is also conduction but you have to be in physical contact with a surface for this to happen, so it is not the usual case for a camouflaged soldier unless wading (it is also in principle a two way process).

So modulating thermal emission changes only one of three (or four) ways of controlling core temperatures, requiring the others to take up the slack.The contribution of thermal emission to body temperature regulation varies with the environmental temperature. At about 33 C it is zero, since this is skin temperature. At higher environment temperatures you can only gain heat this way, not lose it - so being IR white is better. At low temperatures you can lose a lot, and if this bad being IR white is again helpful. But if you need to lose heat to keep from overheating, and the environment is below body temperature then being IR black is good. In general thermal radiation is the least important of the three (or four) processes, becoming dominant only when its cold and you will be snug in your parka anyway.

Is this is a new development, or a same old-same old story with a tweak?

This is looks like a genuine breakthrough of an amazingly cyberpunky kind, the sort of thing science fiction has been famous for "predicting" before it became available. The essential point is that thermal IR emissions are from the true surface of the material. You can't have a "layer of something" on top of the material with the variable emissivity, because then that would be the surface doing the emitting. You must genuinely change the surface properties with something behind the surface. This is a genuine IR optical "paint" that changes color electronically!

And the fact that it uses graphene, nanotubes, and ionic liquids combines buzz-word tech to the nth degree!

You can get the article using Sci-hub.

Re:Where does it go?

[Anonymous Coward]

The summary and the article abstract do no make this clear but what that this device does is change the emissivity of the surface in the thermal IR band, which is around 10 microns. This means it simply alters the thermal emission - it makes is "white" or "black" (or shades of grey) in the IR band, which is far below normal optical bands, to match whatever the emission of the background is.

Long Wave is in the 8-12 um range, but typically between the 8-10. Mid Wave is in the 3-5 range. Both would be thermal, but it's more often a concern for long wave because it does not need to be actively cooled right now.

Re:Where does it go?

[RespekMyAthorati]

I suppose if you were wearing a radiator on your head that
funnelled the IR straight up, that might make you a tad less visible.
Of course, that wouldn't work if you were short.

*switchable* camouflage is the novelty

[DrYak]

The novelty is that this camouflage is switchable. It can be turned on and off.

Otherwise, IR camouflage has been use for quite a long time in the military. (Basically, in an over simplified manner, it boils down to very well insulating clothes). In most country, most of the "green" stuff military wear is well isolated and doesn't radiate much heat.
Even the emergency bandage comes with an extra IR-isolating (also painted green) over-laying band that can mask part of the IR radiation that the underlying wound and bloodied wound derssing could be giving of.

But all this is static (basically, well isolating cloths).

TFA's camo is switchable (between isolation and transmission).

Might have also some non-strategic application (sport clothes to adapt to external temperature ?)

Thick clothes

[DrYak]

You radiate IR for some very good reason.

Yup, you're losing thermal energy.

For years, "thermal camo" has basically boiled down to "a layer of very well insulating clothes" (and face paint, and gloves).

The thing is, in a very hot climate, wearing insulating clothes will make you feel hot.
You would need to undress a bit, which might not be practical in every situation.

If you are wearing a suit of this stuff I imagine you won't be wearing it a long time.

The whole point of this tech is that it's switchable between isolating and radiating mode.
At a single button you can basically transform it from a wool sweater to sport T-shirt and back, without need to remove any layer of clothes (unlike classical thermo camo).
You only turn it on where thermal camouflaging is necessary, instead of wearing an isolating layer for the whole time.

Re:Thick clothes

[Joce640k]

The whole point of this tech is that it's switchable between isolating and radiating mode.
At a single button you can basically transform it....

This will be perfect for burglars trying to get past PIR sensors.

(and freedom-protecting government agents, obviously)

Re:Thick clothes

[arglebargle_xiv]

The thing is, in a very hot climate, wearing insulating clothes will make you feel hot. You would need to undress a bit, which might not be practical in every situation.

The Israeli army have got that sorted.

(Alternative link in case of 404).

Re:Thick clothes

[bluefoxlucid]

PIR sensors don't look for absolute IR; they look for a change in IR image. If you move, it sees you.

Re:Thick clothes

[arth1]

The thing is, in a very hot climate, wearing insulating clothes will make you feel hot.

No, this is only the case for mildly hot climates. In very hot climates, people generally dress in several layers of insulating clothing to keep the heat out.

You would need to undress a bit, which might not be practical in every situation.

Ask a Bedouin whether undressing in the heat of the desert is smart.

Re:Thick clothes

[javaman235]

Why is it so easy to make a hot electric blanket, but not a cold one? Something to do with entropy?

Re:Thick clothes

[drinkypoo]

In very hot climates, people generally dress in several layers of insulating clothing to keep the heat out.

They actually dress in multiple layers of loose fabric to keep the sun off, while still letting the heat out. And they make the women wear black while they wear white, because you can see through sweaty, light-colored clothing and better to cook them than to let someone see the outline of their tits.

Re:Thick clothes

[gnick]

Ask a Bedouin whether undressing in the heat of the desert is smart.

Arrakis can be hostile without your stillsuit.

Re:Thick clothes

[arth1]

I'm disappointed, I thought better of you.
Plenty of desert dwellers have women who wear non-black clothing, often quite colourful. And men who wear black.

It's when you start adding religion (spit!) into the mix that the utility of layered clothing takes back seat to norms and oppression. But when there's no religious concern, desert people still dress in many layers to keep the heat out. When wearing many layers of clothing, the albedo becomes less important, and the colour is of their own choosing.

Re:Thick clothes

[MightyYar]

If your typical burglar has this technology, they would probably have pawned it long before they started breaking into homes.

Re:Thick clothes

[drinkypoo]

I'm disappointed, I thought better of you.

Right back at you.

Plenty of desert dwellers have women who wear non-black clothing, often quite colourful. And men who wear black.

Men who wear black are drastically in the minority.

So are desert-dwelling cultures that wear a lot of cloth and also don't oppress women, by population.

Re:Thick clothes

[MightyYar]

This seems like a throwaway comment but it actually has me thinking. Exciting things hotter than ambient is very easy, as almost any energy input gets converted to heat. You can jiggle something physically or excite it with electromagnetism and it will get excited and slowly lose energy until it returns to ambient. Getting something to cool down requires creating moving energy from one place to another. It's not as "easy" technology-wise but actually it can be more efficient. So an electric blanket that warms via heat pump can be made a lot more efficient than an electric blanket that just pumps electricity into resistive heaters, but that blanket will be very complicated. Entropy plays a role in both a cooler-than-surroundings object and a hotter-than-surroundings object, so I'm not sure if that is the culprit here - the energy used is similar to cool 10 degrees or to warm 10 degrees.

So I think it just comes down to technology - in the absence of a tool of some sort, any activity will generate heat... that's the default. Once you start using technology, cooling and heating are the same problem (moving heat around) and it doesn't really matter. In other words, there are actually two problem sets here, and cooling is in one but not the other. An electric blanket using resistive heaters is not in the same problem set as an electric cooling blanket - that's a different class of problem that includes an electric heating blanket using a heat pump.

This is just me talking out my ass over coffee, so don't be too harsh :)

Re:Thick clothes

[Joce640k]

If the whole room is at ambient temperature you can simply hold up a sheet and walk past one.

https://www.youtube.com/watch?...

A suit made of this would do the same thing.

The only time it would fail is if there was something hot in the room and you walked in front of it.

Re:Thick clothes

[bluefoxlucid]

True. My rooms are usually not ambient due to air circulation, electronic gyzmos, and coupled walls.

Re:Thick clothes

[godel_56]

The thing is, in a very hot climate, wearing insulating clothes will make you feel hot.

No, this is only the case for mildly hot climates. In very hot climates, people generally dress in several layers of insulating clothing to keep the heat out.

Ask a Bedouin whether undressing in the heat of the desert is smart.

The desert environment combines very hot temperatures with very low humidity, so the evaporation of sweat has a profound cooling effect. The air inside their robes is substantially cooler than the air outside. This tactic will NOT work in a climate with high heat and high humidity. Try wearing Bedouin robes in the amazon jungle and see how long you last.

Re:Thick clothes

[arth1]

The desert environment combines very hot temperatures with very low humidity, so the evaporation of sweat has a profound cooling effect. The air inside their robes is substantially cooler than the air outside. This tactic will NOT work in a climate with high heat and high humidity. Try wearing Bedouin robes in the amazon jungle and see how long you last.

True. I also suspect that risk of snagging is much higher in rain forests than in deserts, making large robes and loose clothing less functional.
But if it's just heat and not humidity (or branches or norms), I'd layer with as much air as possible between me and the environment. And a hat, even when the sun isn't hitting me.

Arnie did it in "Predator"

[Anonymous Coward]

Useless "scientists".

Arnold Schwarzenegger did just that in Predator.

Probably served him well when he was Duh Governator and wanted to slip out and pork his maid...

Re:"Camouflaged a hand owned by a subject"

[Anonymous Coward]

Yeah, I know. Who the hell is rich enough to own a hand? I've been renting my hands but I'm saving up to be able to afford to buy a nice set of used hands by next year.

I don't want everyone to know about this.

[sabbede]

It just sounds like the sort of thing that would have military applications, and perhaps be the key to many more. So why didn't DARPA snap it up before it was published somewhere China would see it?

Re:I don't want everyone to know about this.

[afidel]

MIT has solved industrial production already. Not sure what the cost is but it's definitely far below lab sample $10,000/g levels.

Re:I don't want everyone to know about this.

[AHuxley]

The spies in every US university ship all results back to their own nations every year. The USA has no secrets as the spies learn at the same rate the best in the USA are educated at.

Re:"Camouflaged a hand owned by a subject"

[The Fat Bastard]

Ex-military personnel who lost a hand while serving may own several different prosthetic hands. Military camo is a popular option.

I always wanted to check out the world of

[H3lldr0p]

Ghost in the Shell.

This stuff. Themoptical camo. It's a few story points throughout the book and how it's used to evade and so forth. It's also very Cyberpunk. Computer brain interfaces. The world's data at the tips of my thoughts. It's all cool.

Until you look at the poverty, the political situations, the fact that you can brainwash people and implant memories...reality is kinda fucked up there.

So, yeah. If we could get everyone to stop going down this direction in history, I think we might all end up happier in the long run.

Re:Very expensive camouflage ...

[jellomizer]

For the most part (there are exceptions that will always happen) the simple solutions have been already been found that often solve the big problem. Then as advancements go on the smaller problems become the big problem, which then needs more complex solutions.

Proto-man: I don't want to freeze to death, solution hide in a hole.
Early man: I want to move around and not freeze to death, solution Take the fur of other animals and wear them.
early human: I want greater movement and not having it fall off, solution cut the fur into shapes and tie them together to cover the body better. ...
To today we are trying to make clothing that will block a wavelength of light we only discovered to exist a little over 200 years ago, to prevent detection from a device invented less then a hundred years ago, which only has been in active use for military reasons for over a generation.
We need high tech and complex solutions to fight off counter high-tech and complex solutions.

Civilian Application

[Zorro]

Thinner and warmer coats.

Same way GORE-TEX was adopted by hikers and fisherman.

Been here, done that

[thunderclees]

The Taliban were using space blankets to try a defeat IR and it worked sometimes

Re:Hardly new

[freeze128]

...And the Romulans figured it out 25 years before that.

Re:"Camouflaged a hand owned by a subject"

[cyberchondriac]

Perhaps the article is actually referring to the "Hand of Glory", which purportedly conferred some level of camouflage (darkness) to the burglar schooled enough in the arcane arts to use one.
The new and improved models block IR now too.

Re:Mandatory predator reference

[Tough Love]

Mandatory predator reference.

Redundant, what? Some dunce with mod points?

Is this expensive styrofoam?

[cyn1c77]

Seriously, what is the advantage of this over a removable insulating jacket? ... or the mud that Arnold uses in the Predator?

Also, what are the relevant time constants? Once switched on, surely this material cannot maintain low thermal emmisivity forever when strapped to a hot object?

I have a need ... a need for ...

[Tjp($)pjT]

I need some of this for my car... lol