After several attempts, the researchers found a level which "inactivates both viruses and bacteria while leaving sensitive materials such as mammalian cells unharmed".

BBC: Cell infected with HIV

But Mr Moynahan uses Russian archive materials to chronicle Rasputin's life in exhausting detail, leaving few of its peculiarities unexplained.

ECONOMIST: Russian history

Since the robocasting machine allows the researchers to manipulate several inks at once, they are able to make new kinds of composite materials this way interlacing the filigrees, and even leaving holes in the material if that helps to arrive at the desired properties.

ECONOMIST: A new way to build complicated materials, micron by micron