Toronto-based Cymat makes the foam by mixing ceramic particles with molten aluminum and blowing gas into the mix. The bubbles that form remain until the metal cools, leaving behind a foam-like structure. "It's like blowing bubbles into chocolate milk," explains Michael Liik, CEO of Cymat. "If you blow bubbles into regular milk, they disappear when you stop blowing. But when you do the same with the chocolate variety, they stick around." That's because the chocolate particles shore up bubble walls and keep the milk contained.