SciTech

Metallic wood as strong as titanium

Titanium is a highly commercialized metal with a broad range of applications, from golf clubs to airplane wings. With the same strength as steel but half the density, titanium also boasts a high resistance to corrosion, making it ideal for withstanding extreme conditions that other metals cannot. However, with rampant technological growth comes the need for more advanced materials — ones that do not occur naturally.

Enter metallic wood.

In a new study published in Nature’s Scientific Reports, researchers at the University of Pennsylvania, the University of Illinois at Urbana-Champaign, and the University of Cambridge have succeeded in creating “metallic wood," something that has the same strength as titanium but is four to five times lighter. As the name suggests, the secret is in the assembly process: composed of nickel in porous sheets, the structure mimics that of wood without compromising any integrity. What’s more, because the material is still metallic in nature, the internal cavities can help with storing and propagating energy, thus allowing the creation of mechanisms that can serve a functional purpose while also acting as capacitors. These properties open a broad range of possibilities, especially for devices that are energetically independent without a reliance on bulky battery packs.

The motivation for this study came from the fact that materials, no matter how crystalline or perfect, still have defects that compromise performance. This issue is especially common when raw metals are not strong enough for commercial uses; hence, the process of alloying was devised to combine different metals and create interstitial combinations, a whole that exceeds the sum of its parts. But even this process has its limits, and by taking control of material design at the nanoscale level, these defects can be mitigated.

So does this mean that metallic wood will soon replace titanium? Probably not, especially since the global demand for titanium continues to grow thanks to the automotive and construction industries. Currently, the process of creating metallic wood is fairly involved and not nearly efficient enough to yield the gargantuan outputs that would be required, though it will surely improve in the future. Research is ongoing, and we will likely see this new material expand beyond its niche uses into everyday life.

Perhaps even more exciting is what this new approach to material synthesis entails. Could this same method be used for biological materials? Is there a limit to improving mechanical efficiency? Might this new approach help our ailing environment? Only time will tell.