This robot runs, climbs, and opens doors -- without a gearbox

Ghost Robotics, a new R&D firm founded by University of Pennsylvania PhD candidates, has unveiled a dog-like robot that runs, climbs, leaps, and even uses its legs to open doors. While other research groups have already created similar adorable and functional robots (MIT's cheetah, for example), this one is different because it is completely gearless. In technical terms, Ghost Minitaur is the first direct-drive legged robot using conventional rotary electric motors. What that translates to in real life is the patent-pending design eliminates the gearbox, which is a part that is expensive, complicated, and fragile. Direct drive also gives the motors the ability to act like springs, since the legs are adjusted and controlled via software instead of hardware.