The idea of building a robotic third arm is nothing new. We have seen plenty of attempts at that. Mechanical engineers at Rice University’s George R. Brown School of Engineering have built a handy extra limb that can grasp objects. It is powered by compressed air. As the researchers explain:
The system requires two components: textile pumps embedded in the soles of walking shoes that harvest air pressure and pneumatic actuators that make use of that pressure where needed.
The pumps have open-cell polyurethane foam to recover their shape after every step.