Pikul’s method starts with tiny plastic spheres, a few hundred nanometers in diameter, suspended in water. When the water is slowly evaporated, the spheres settle and stack like cannonballs, providing an orderly, crystalline framework. Using electroplating, the same technique that adds a thin layer of chrome to a hubcap, the researchers then infiltrate the plastic spheres with nickel. Once the nickel is in place, the plastic spheres are dissolved with a solvent, leaving an open network of metallic struts.
“We’ve made foils of this metallic wood that are on the order of a square centimeter, or about the size of a playing die side,” Pikul says. “To give you a sense of scale, there are about 1 billion nickel struts in a piece that size.”
https://medium.com/penn-engineering/penn-engineers-metallic-wood-has-the-strength-of-titanium-and-the-density-of-water-a8d8573c6bcIt's basically just metal foam (
https://en.wikipedia.org/wiki/Metal_foam ) except massively small, so it's more like wood. In addition it's far, far, stronger and lighter than real metal as there is less room for unordered atoms in the metal's crystalline structure.
Producing it seems to be a challenge, but one that I imagine should be easily overcome once engineering techniques are developed.
