nunu

[fig. 1: carbon nanotubes]

From the frontiers of human knowledge:

A group of nanotechnology researchers at Rensselaer Polytechnic have succeeded in creating “the blackest material known to science”. By shaping a whole bunch of carbon nanotubes into a light-sucking ‘forest’ of darkness, the Rensselaer group came up with a hockey puck of extremely black, extremely chic metal which absorbs 99.6 percent of all the light hitting it. “When we were trying to do some experiments with, you know, light and laser beams,” said one of the inventors, “We couldn’t find the beam for a while because [the hell-of black disc] is absorbing so much.”

Guest nunu contributor Ryan Saylor talked to Dr. Jessica Thomas, an editor at the monthly research journal Nature Nanotechnology, about just how black the future looks for fashion.

the nunu: What are the implications for using this substance as a garment?

Dr: Thomas: This is just a guess here, but I think that one limitation would be how flexible one could make these materials. The authors of the study grew carbon nanotubes, which are cylinders of a single layer of carbon (one atom thick), on a flat substrate. I have seen such things before and they look like a furry, black carpet (it might remind you of the soft side of a Velcro snap). They didn’t say in the paper what this substrate was – likely some sort of metal or semiconductor. I don’t know that it would be so practical to grow these nanotubes on a large scale surface; rather, you could maybe have to ‘plate’ together a bunch of these miniature substrates. By the way, the touted applications at the end of this article are solar cells and detectors.

Yeah, those will be awesome probably. So, can we make nano-thin, nano-black tops/stockings?

The nanotubes are only about 10 nanometers in diameter [Ed. note: very small], but they are almost 1 millimeter long. I gathered from the paper that the thickness is important here because light gets trapped in the thick carbon nanotube carpet. I have never measured the thickness of my stockings, but I am pretty sure they are much less than a mm thick!

If this new material gets any blacker, how will scientists know it’s there?

It’s true that this material doesn’t reflect any light, so you can’t ‘see’ it (where seeing is defined as perceiving the light that arrives from an object). However, if it is surrounded by things that you can see, you will see its silhouette. In terms of ‘covert operations’ I could see it being used at night – in a pitch black sky, you wouldn’t see it at all.

That said, I am not sure that I know how sensitive the human eye is once the reflectance gets so low. For example, I don’t know if you would be able to tell the difference between a black cloak made of felt or this stuff. In this sense, what may be more important is that electronic detectors cannot see it.

Will scientists be able to create an all-white, perfectly reflective nano-material? What would the garment implications be?

Well, a mirror is more what I would call perfectly reflecting because it is perfectly smooth (at least on the length scale of the wavelength of light). You don’t really need nanotechnology to do that: the wavelength of light is about 400-700 nm so if the surface is smooth on the scale of 1-10 nm or so and it is made from a reflecting material (like silver) it will be perfectly reflecting. I think the limit here for garments is how to stitch together, seamlessly, reflecting units. Anywhere you have a seam, you will see a break in the reflection. I have heard of the military developing armor that projects on the front an image of what one would see if the person wearing the armor were not there, in effect, making a person invisible against his surroundings. Now that is amazing.

Will this black go with anything? –Will it get dirty?

I think someone who touches it will get dirty! It’s made of carbon nanotubes, which is a byproduct that forms in carbon arc melters. It might be a little bit like running your hand on the inside of a chimney! Of course, I think the carbon nanotubes are pretty well attached to the substrate in this case, so this might not be such a problem. Another thing to keep in mind is that the medical implications of breathing carbon nanotubes are not completely known.

Sometimes looking good means flirting with danger. What has nanotechnology contributed so far to fashion? -Because this might be the best thing.

I think the stain resistant materials that you can get out there are supposed to be based on nanotechnology.

What about a pair of nano-scale earrings? Wouldn’t that be cool?

And how would you find those in the morning? It’s an interesting gift idea from a lazy or cheap boyfriend. He tells the woman he bought her the state of the art in nano jewelry and she doesn’t know whether he is a genius or a loser…

Yeah, she would probably make a ‘nano’-joke about something else.