Behold: The Tightest Knot Ever

By Holly Brockwell on at

A team of scientists from the University of Manchester has successfully created a 192-atom, eight-crossing knot that paves the way for exciting new materials. Measuring 20 millionths of a millimetre across, the knot braids molecular strands together in a tighter formation than ever before, as reported today in the journal Science.

The team was led by Professor David Leigh from the university's School of Chemistry, and adds to Manchester's proud research heritage - 25 Nobel laureates have worked or studied there to date.

Professor Leigh, presumably a former Scout, explains: "We ‘tied’ the molecular knot using a technique called ‘self-assembly’, in which molecular strands are woven around metal ions, forming crossing points in the right places just like in knitting - and the ends of the strands were then fused together by a chemical catalyst to close the loop and form the complete knot."

Leigh expects the new knot to have exciting applications for fabric technology: "Tying knots is a similar process to weaving so the techniques being developed to tie knots in molecules should also be applicable to the weaving of molecular strands.

"For example, bullet-proof vests and body armour are made of kevlar, a plastic that consists of rigid molecular rods aligned in a parallel structure - however, interweaving polymer strands have the potential to create much tougher, lighter and more flexible materials in the same way that weaving threads does in our everyday world.

"Some polymers, such as spider silk, can be twice as strong as steel so braiding polymer strands may lead to new generations of light, super-strong and flexible materials for fabrication and construction."

The new discovery puts paid to the theory that nothing can be more knotted than tights in a washing machine, but sadly offers no help with untangling them.

Photos: Robert W. McGregor/University of Manchester