The new technique is straightforward. The magic sauce is a liquid metal: an alloy of gallium and indium which is liquid at room temperature. They simply pump it through an inkjet printer to create a fine spray of liquid metal droplets that settle onto the substrate.
The droplets rapidly oxidise as the travel through the air and this oxide forms a surface layer on each drop that prevents further oxidisation. Thatâ€™s handy because the liquid metal itself does not easily adhere to the substrates. But the metal oxides do and this is the reason, say Jing and co, that the circuits adhere so well to a wide range of surfaces.
Combined with 3D printing a liquid metal circuit printer would take electronics prototyping to a whole new level.