Growing “Metallic Wood” to New Heights: Radically Decreasing a Material’s Density Without Sacrificing Strength
2nd July 2021
For the past three years, engineers at the University of Pennsylvania’s School of Engineering and Applied Science have been developing a type of material they’ve dubbed “metallic wood.” Their material gets its useful properties and name from a key structural feature of its natural counterpart: porosity. As a lattice of nanoscale nickel struts, metallic wood is full of regularly spaced cell-sized pores that radically decrease its density without sacrificing the material’s strength.
The precise spacing of these gaps not only gives metallic wood the strength of titanium at a fraction of the weight, but unique optical properties. Because the spaces between gaps are the same size as the wavelengths of visible light, the light reflecting off of metallic wood interferes to enhance specific colors. The enhanced color changes are based on the angle that light reflects off of the surface, giving it a dazzling appearance and the potential to be used as a sensor.