Scientists have engineered a new “super wood” that is reportedly stronger than both spider silk and steel. Researchers said because the material is lightweight and biodegradable, it could be “an eco-friendly alternative” to materials used to make cars, furniture, airplanes and other products.
The new material is “the strongest bio-material that has ever been made,” according to the team of researchers at KTH Royal Institute of Technology in Stockholm who developed it. Their work was published last week in the journal ACS Nano.
The team used cellulose nanofibres, which are a crucial building block for wood and other plant life. These fibres coat the cell walls of wood and are more than five times stronger than steel, but only a fifth of the weight.
Using a process called hydrodynamic focussing, the team aligned the fibres into a tightly packed, macroscopic thread held together by supramolecular forces. In doing so, they transferred the remarkable mechanical properties of these fibres to a larger, lightweight material with a tensile strength nearly four times greater than that of steel.
“The bio-based nanocellulose fibres fabricated here are eight times stiffer and have strengths higher than natural dragline spider silk fibres,” lead researcher Daniel Söderberg said in a statement. “If you are looking for a bio-based material, there is nothing quite like it.”
Söderberg noted that the new material is “stronger than steel and any other metal or alloy as well as glass fibres and most other synthetic materials. Our new material even has potential for biomedicine since cellulose is not rejected by your body.”
The artificial cellulose fibres can be woven together to create a fabric or other materials for various purposes. Producing the new material would be cost effective – the team said they expect production costs to compete with those of strong synthetic fabrics.
Material scientists have been trying to reproduce the properties of spider silk at the industrial level for decades, reports Wired.
Söderberg said the study could open up new opportunities to develop nanofibre material that can be used for larger structures while maintaining the nanofibres’ properties, including tensile strength and ability to withstand mechanical load. The process can be applied, for example, to assemble carbon tubes and other nano-sized fibres.
“We can now transform the super performance from the nanoscale to the macroscale,” Söderberg explained. “This discovery is made possible by understanding and controlling the key fundamental parameters essential for perfect nanostructuring, such as particle size, interactions, alignment, diffusion, network formation and assembly.”
The new material is the second super-strong, wood-based material to be developed in recent months. Earlier this year, a team of scientists at the University of Maryland in the United States developed a wood-based material that is more than ten times stronger than regular wood. The scientists who created it say it is just as strong as steel, but six times lighter and five times thinner.
What applications could have the discovery of this super wood for carpentry? Is it as aesthetic as the other noble woods?
Nature, indeed, is a great teacher.