This robot dog has learned to open doors with its leg 🤖🦿 This robot dog can use a leg to open doors, press buttons and pick up rucksacks while balancing on its other three legs. Four-legged robots like Spot, the star of Boston Dynamics’ viral videos, normally require an extra arm attached to their body to open doors or pick up objects, but this can add significant weight and make it harder for the robot to squeeze through narrow spaces. Philip Arm at ETH Zurich in Switzerland and his colleague