Kwang Kim’s hydrogen muscle (Image: Kwang Kim)

IF ROBOTS are ever going to be welcome in the home they will need to become a lot quieter. Building them with artificial muscles that run on hydrogen, instead of noisy compressed-air pumps or electric motors, could be the answer.

Kwang Kim, a materials engineer at the University of Nevada in Reno, came up with the idea after realising that hydrogen can be supplied silently by metal hydride compounds.

Metal hydrides can undergo a process called reversible chemisorption, allowing them to store and release extra hydrogen held by weak chemical bonds. It’s this …