MIT foamed aluminum research (Gibson)

Ordinarily you're trying to get rid of the gas. Here's an example where you go the exact opposite direction. A lot of times you come up with some pretty clever things if you do the opposite of whatever the conventional wisdom is. Here's foamed aluminum, made by a similar process to styrofoam. With styrofoam you take molten plastic and inject gas — they used to use Freon, probably some hydrocarbon now. You don't inject oxygen or air into molten plastic, it tends to burn, so you inject something that won't cause burning. In this case I think they foamed it with nitrogen. Very light. It has all the strength of a piece of styrofoam too — so don't push on it too hard.