Microscale knots double tensile strength of new material

Knots are known for boosting the tensile strength of materials, including the tiniest twists of DNA. The California Institute of Technology (Caltech) in Pasadena reports that engineers there have developed a new material consisting of microscale knots and shown that it’s far tougher than a version of the material without knots.

The material is made of polymers arranged in a series of basic overhand knots, with an extra twist to absorb more energy. The fibers aren’t physically tied into these knots; rather, they’re 3D-printed into that shape, which is simpler to produce and keeps them from coming undone. Each knot measures about 70 micrometers high and wide, making this the first time a material has been composed of knots of this scale. The knots allow the material to absorb 92% more energy and sustain more than twice the amount of strain before breaking than the other architecture. 

The team says that the durability and deformability of these kinds of knotted materials could eventually make them useful for biomedicine and aerospace applications. In future work, the researchers plan to investigate materials made with more complex knots. The research was published in Science Advances. Image: Caltech