Researchers demonstrated a new process that makes wood stronger than steel. According to the University of Maryland mechanical engineers, their novel process could lead to a greener alternative to metal in automobiles, airplanes, or buildings. "This could be a competitor to steel or even titanium alloys, it is so strong and durable," says researcher Liangbing Hu. "It's also comparable to carbon fiber, but much less expensive." From the University of Maryland:
The team's process begins by removing the wood's lignin, the part of the wood that makes it both rigid and brown in color. Then it is compressed under mild heat, at about 150 F. This causes the cellulose fibers to become very tightly packed. Any defects like holes or knots are crushed together. The treatment process was extended a little further with a coat of paint.
The scientists found that the wood's fibers are pressed together so tightly that they can form strong hydrogen bonds, like a crowd of people who can't budge – who are also holding hands. The compression makes the wood five times thinner than its original size.
The team tested their new wood material and natural wood by shooting bullet-like projectiles at it. The projectile blew straight through the natural wood. The fully treated wood stopped the projectile partway through.
More: "Crushed wood is stronger than steel" (Nature)