Rings and Bells

Looking a bit like annoying logic puzzles, these rotaxane shapes could change the world of medicine – and electronics, too, for that matter. Each tiny device has a rotating ring (coloured gold here) that is free to slide up and down a dumbbell shape (blue). It might not sound like much, but rotaxanes can be slotted into machines as rotors or ratchets. Now the really clever part – these rotaxanes are made from folded strands of DNA, 100,000 times smaller than those fiddly metal puzzles. DNA origami uses the DNA’s code to create edges and ends that stick together automatically; making millions of these devices is a matter of a few chemical reactions. So if you’re looking to make a tiny motor to fit inside a cell, or a molecular bomb that releases drugs inside a tumour, this might be a vital piece in your design.

Written by John Ankers

John Ankers

Writer

A former researcher in systems biology, John is now an online biology tutor and professional coach supporting the wellbeing of scientists and NHS professionals. He's writing, too, of course.

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• Image from work by Jonathan List and colleagues
• TUM Department of Physics Technical University of Munich, Germany
• Image originally published under a Creative Commons Licence (BY 4.0)
• Research published in Nature Communications, August 2016