Spiderman and Superman move over… the world’s next superhero could well be The Woodsman – a fearless fighter who battles evil while clad in armour woven from a nanofibre biomaterial derived from wood.
Spider silk has long held the title of strongest natural biomaterial, however scientists have been trying for years to harness it, mimic it and even improve on the substance. Now, researchers at Sweden’s KTH Royal Institute of Technology have developed a new biomaterial that steals the strength record.
The ultrastrong material is made of cellulose nanofibres (CNF), the essential building blocks of wood and other plant life.
Dr Daniel Söderberg, Director of Treesearch and a member of the research team at KTH, said the bio-based nanocellulose fibres they fabricated were eight times stiffer and several times stronger than natural dragline spider silk fibre. He added the CNFs also had strength exceeding that of metals, alloys, ceramics and E-glass fibres.
The researchers used a process called hydrodynamic focusing to align the nanofibres in the right direction and into a well-packed macroscopic thread. The technique involved suspending nanofibres in de-ionised and low pH water set in 1mm-wide channels. As the water flowed through, it helped align the CNFs to self-organise into tightly-packed bundles.
This novel production method allowed the researchers to successfully transfer the unique mechanical properties of these nanofibres to a lightweight material that doesn’t require glue or any other component. This is due to the tight threads of nanofibres being held together by the supramolecular forces (for example electrostatic and Van der Waals forces) between the fibres.
Dr Söderberg suggested the new material has potential for biomedicine, since cellulose is not rejected by the human body.
It could also be used as an eco-friendly alternative for plastic in airplanes, cars, furniture and other products. Superhero armour, however, is still just a fantasy.
Photo Credit: Nitesh Mittal, KTH Stockholm
Source: KTH Royal Institute of Technology, American Chemical Society (via EurekAlert). The research was published in the journal ACS Nano
