No fewer than two separate companies are now working on manufacturing techniques for high grade transparent aluminum. For a while, they were dancing around using the term “transparent aluminum”, because the various means of producing a transparent metal so far all use aluminum but not as the primary element. The idea of using the already popularized term “transparent aluminum” was too seductive to be ignored; transparent aluminum it is.
According to Star Trek canon, transparent aluminum is used on everything on a starship that has to be exposed to space and still pass light. Portals and windows would all be made of it. The whole idea started with this iconic scene from Star Trek IV: The Voyage Home, in which Scotty teaches a plastics expert from 1986 how to make the now legendary metal.
Star Trek is used so much as the inspiration for new technology that having a scene like this in a Star Trek movie is the rough equivalent of grabbing every geeky engineer on the planet by the ears, aiming their noses at the problem and saying “here, look at this”. By 2005 we heard the first announcement that somebody was working on it, and today two different organizations have working production methods that allow them to manufacture something each is casually referring to as transparent aluminum.
The first is the one you might expect to be working it: the United States Navy. They’re working on something they call Spinel, which is created by thermoforming a powdered form of magnesium aluminate. It’s not as transparent as glass, but it is transparent. Though somewhat less transparent than traditional bulletproof glass, it does do something bulletproof glass cannot do: it can pass infrared. This means it’s possible to make protective housings for sensors on things like industrial robots and flying drones that need to be able to use infrared to see targets or find their way around.
The other organization isn’t the military. It’s Surmet Corporation, and their version of the idea is based on a material called aluminum oxynitride, or ALON for short. ALON isn’t quite true transparent aluminum either. It’s actually more like a strange hybrid of aluminum and ceramic, but it has better clarity than the Navy version. It’s also the only one being manufactured by a private company, and Surmet currently is the only company on the planet that makes it.
Like the Navy’s method, ALON can be formed in molds to virtually any shape. The down side is that it must then be subjected to temperatures hot enough to melt aluminum, or a little over 1,200 degrees (660 degrees Celsius). The ability to do that is the limiting factor, and means that so far they can only make small pieces. The Navy’s version and Surmet’s version both suffer from this problem. ALON as a bulletproof glass replacement is made in three layers: the bulletproof outer layer of aluminum oxynitride, then a layer of glass, then a polymer backing. It can stop a bullet in half the distance regular bulletproof glass can, is far more resistant to the elements, and does not ablate the way glass does. It’s also half the weight of traditional transparent armor. While it does cost more, between three and five times what normal bulletproof glass does, not having to replace it so often makes it the better bargain.
Here’s a demonstration video comparing traditional bulletproof glass to Surmet’s optical ceramic product:
ALON can be made, so far, into flat panels as big as 18″ by 35″ and windows with engineered seams as large as 24″ by 27″ to the US Defense market. (Yes, so far only the military is using this. You can’t just buy a piece and mount it in your car so far as we know.)
That’s two ways to get transparent aluminum, but there’s a third way that actually makes real, honest to gosh transparent aluminum – bombard a small area of a piece of aluminum with the world’s most powerful soft X-Ray laser. This works by blowing one electron off each atom in the metal at the target point and produces a new state of matter, and yes, the aluminum becomes completely transparent. There are, however, a couple of catches, apart from requiring a stupidly powerful and expensive laser to produce the effect: when you turn off the laser, the electrons jump back into place, and the transparent aluminum becomes normal metal again – and it’s only transparent over the diameter of about a human hair, the width of the beam itself. In other words, close, but no cigar.
We used to watch Star Trek and marvel at what the future could hold for us. Generations of scientists and engineers have been inspired in their career choices by Star Trek – with the result that nowadays, we look at Star Trek more as an early bird shopping guide for the stuff that’ll be out next year. Say hello to commercially available transparent aluminum.
So, dear reader – if you could make anything you’ve seen on Star Trek that hasn’t been made already, what would you make? I mean, besides the new Bluetooth Star Trek Communicator that ships in January?
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President of Krypton Media Group, Inc., radio personality and station manager of SCIFI.radio. Part writer, part animator, part musician, part illustrator, part programmer, part entrepreneur – all geek.