Scientists at University of Nevada, has discovered a method that enabled them to produce hydrogen muscles, which run so silently that in the long run could be the answer to the noise problem of today’s robot actuators. Through certain chemical procedures, the researchers were able to store and release hydrogen that are being used in these new type of artificial muscles. Most importantly, the system is able to give enough power that is needed in many robots that will be expected to do everyday tasks in the near future. This may be considered another major method of moving the robot mechanical parts once fully developed. For more details on the working mechanism of this new method, see the article referenced below.

Reference: www.newscientist.com/article/mg20427305.600-hydrogen-muscle-silences-the-domestic-robot.html