In a major step towards developing miniature machines that could one day move through the body to deliver drugs or administer insulin for diabetics when needed, researchers have built the smallest, fastest and longest-running synthetic motor to date.

With all its dimensions under one micrometre in size, the nanomotor could fit inside a human cell and is capable of rotating for 15 continuous hours at a speed of 18,000 RPMs - the speed of a motor in a jet airplane engine.