Robot millipede printed by 3D printer that can spew out multiple materials

It's historically been tough and slow-going to 3D print objects made from multiple materials. Now, Harvard researchers developed an ingenious nozzle that enables the 3D printer to spew out eight different materials at the resolution of a human hair. To demonstrate the system, they printed fantastic flexible origami structures and even a "soft" robotic millipede from a variety of epoxy and silicone elastomer inks. Mark A. Skylar-Scott, Jochen Mueller, and their colleagues from Harvard's Wyss Institute for Biologically Inspired Engineering presented their work in the scientific journal Nature: "Voxelated soft matter via multimaterial multinozzle 3D printing"