Cars Made from an Almost Bullet-Proof, "Tougher-Than-Steel" Wood? Why Not.

Which is stronger? Wood or steel? If you say steel, then you're wrong--that is, if you're talking to  Liangbing Hu, head of the research team at the University of Maryland, James Clark School of Engineering.

According to Liangbing Hu, the material can be stronger than steel or titanium. "This could be a competitor to steel or even titanium alloys, it is so strong and durable," says researcher Liangbing Hu.

He also adds that the processed wood is similar to carbon fiber, although less expensive. "This kind of wood could be used in cars, airplanes, buildings--any application where steel is used," Hu added.

How It Works

Wood can actually be stronger than steel that involves a chemical bath and a hot -press. According to Li Teng, a mechanical engineer at the University of Maryland in College Park and co-author of an article about these "super woods" in Nature (February 8),  this process can revolutionize an often underrated, renewable resource into something that can change car manufacture in the world.

Wood, which contains a substance called lignin, gives it the rigidity and brown color that it's known to have. Taking it out and compressing the entire wood at 150 degrees Fahrenheit the entire day causes the cellulose fibers to become extremely packed. The result is an extremely tough wood.

How strong is it? According to a press release by James Clark School of Engineering: "This new way to treat wood makes it 12 times stronger than natural wood and 10 times tougher."

And despite being only five times thinner, it was three times the density and six times lighter compared to natural wood.

How They Tested the Material

They tested the material's toughness by using a similar method used to test the durability of military vehicles

The researchers had put together five layers, or around 3mm thick, of this wood, and shot pellets at it using a ballistic air gun

The results reveal that the projectile went straight through the natural wood, while the "super wood" was able to stop a 46-gram steel projectile that traveled around 30 meters per second partway through. And while the resulting projectile was not as fast as a bullet, its speed was as fast as a moving vehicle before a collision.

Other Alternatives Methods

According to Fred Kamquaw of Oregon State University, creating a "super wood" is still possible even if you don't remove lignin. In fact, there are other cheaper methods that can be used to create it.

According the Kamquaw, resins and using higher temperatures through steaming can also achieve the same result.

“These other methods are probably much less expensive than a 7-hour boil in a caustic solution,” Kamquaw said. According to him, he was able to stop a 9 mm bullet from a handgun just by creating 24-layers of densified wood.

Still, taking out even a portion of lignin can make a difference. Co-researcher Fu Ling Bian added: "By removing moderate lignin, it is possible to bring out the best strength of wood. We also know that too low lignin will result in low density and fragile material."