Robotic big cat

A robotic cat designed by Boston Dynamics of Waltham, Masachusetts (with funding from the US Defence Advanced Research Projects Agency) has broken the speed limit for four legged robots by running at over 30 kilometres per hour.   At present the big cat is tethered to a treadmill but there are plans to let this metal feline run free later this year.    It  runs just like a real cheetah by using a short gait at low speed and increasing its  stride by flexing and unflexing its back with every step as it goes faster.   Yes, but can it purr?