Improvements to Boston Dynamics' Cheetah robot have allowed it to set a new speed record, running at 28.3 mph — faster than Usain Bolt's top speed of 27.78 mph. Engineers have optimized the algorithms controlling the robot's legs, which mimic those of its biological namesake, far outstripping the robot's previous record of 18 mph, though it still runs on a treadmill with a supporting arm.

Funded by the Defense Advanced Research Projects Agency (DARPA), Boston Dynamics is most famous for building the BigDog, an eerily lifelike robot designed for the US military. As well as the Cheetah, the company is also working on a freestanding, outdoor variant known as the WildCat, which is expected to be demonstrated early next year.