Knots are known to increase the strength of materials, from the tiniest twists in DNA to (potentially) the very structure of the universe. Now, engineers at Caltech have developed a new material composed of microscale knots and shown it to be much stronger than versions of the same material made without knots.
The material is made of polymer and consists of a series of basic overhand knots with an extra twist to absorb more energy. However, the fibers are not physically attached to these knots. Instead, it’s easier to manufacture and 3D printed to its shape to prevent unraveling. The height and width of each knot is approximately 70 micrometers, a first for a material composed of knots of this scale.
The knotty material was stress tested and stretched to the breaking point. This was compared to a version of the material made of the same material, but with an interwoven structure instead of a knot. It was able to absorb, sustain more than double the strain, and burst.
caltech
The team says the durability and deformability of these types of knotted materials could ultimately prove useful in biomedical and aerospace applications. We plan to investigate materials made with complex knots.
“The ability to overcome the common trade-off between material deformability and tensile strength [the ability to be stretched without breaking] This research provides a new way to design devices that are highly flexible, durable and capable of operating in extreme conditions,” said Widianto P. Moestopo, lead author of the study.
A study was published in a journal scientific progress.
Source: California Institute of Technology
