Synthetic flagella spin and contract at the expense of chemical fuel

New mechanisms that transduce chemical potential into work are needed to advance the field of nanotechnology, with the ATP-fueled archaeal flagellar rotational motor being the ultimate inspiration. We describe microns-long ribbons assembled from small peptides that catalyze the conversion of a nanometer-sized molecular fuel. This conversion drives a morphological transition of the flat nanoribbons into helical ones and eventually into tubes, which makes the ribbons spin. Remarkably, the spinning speed and directionality can be tuned by molecular design. Moreover, the nanoribbons exert pN forces on their surroundings, allowing them to push micron-sized objects or even crawl. Our work demonstrates a new mechanism by which chemical energy at the nanometer level is used to power micron-sized machinery. We envision such new mechanisms opening the door to micro- and nanoscale autonomous machines.