No joke. Some researchers are working on the development of a new prosthetic arm that is powered by steam! The article, HERE, explains how the arm uses a catalyst to burn hydrogen peroxide and create pure steam to power it for up to 18 hours of normal use. The steam system produces ten times as much power as other prosthetics but still won't make anyone into a superhuman steampunk robot-arm having hero. Still, it's one of the coolest devices ever to run on hot water-vapor that I've ever seen. Think it will come in copper and brass finish?