In the latest issue of the materials science journal Matter, the UMD scientists detail their process. First they put the natural wood through a chemical process called delignification, in which the lignin (a polymer that lends rigidity to wood and bark) is removed from the material. This makes the wood flexible and squishy, which may sound backwards at first, but is vital to the next step in the process. The scientists then densify the wood by putting it in a hot press, in which both heat and pressure are applied. The result? Hardened wood, or HW, which is 23 times harder than the starter material.
The strength found in HW relies on the cellulose packed inside, which makes up nearly half of wood’s natural components. The cellulose offers more structural integrity than certain man-made ceramics and metals, making wood a viable option for construction and cooking.
From here, it’s just a matter of turning the HW into a usable product by carving the material and polishing it with mineral oil (an essential agent in making the HW water-resistant and long-lasting). The team at UMD used their fresh-pressed HW to create nails and knives, both of which stood up to their more traditional metal counterparts. As it turns out, HW nails are as strong as steel nails, but come with the added bonus of being rust-resistant. HW dinner knives boast triple the strength of steel dinner knives—and yes, they can be thrown in the dishwasher after a nice steak dinner.
Much of the team’s motivation for creating HW tools appears to be environmentally-focused. “Widely used hard materials, e.g. alloys and ceramics, are often nonrenewable and expensive. Their production requires high energy consumption and often leads to negative environmental impacts,” the study reads. Steel, for instance, is particularly susceptible to supply chain issues and must be forged under extremely high temperatures. Finding ways to turn bulk natural wood into HW allows scientists to create the potential for sustainable and low-cost alternatives to current manufacturing methods.
Plus, there’s something to be said about the elegance of a wooden knife on the dining table.
Source From Extremetech
Author: Adrianna Nine