The researchers at the Massachusetts Institute of Technology have succeeded in producing tiny robots directly from a 3D printer that respond to magnetic fields. The trick is on the one hand in the material (a mixture of silicone rubber and tiny magnetic microparticles), on the other hand in the extrusion. An electromagnet is grouped around the printer nozzle, aligning the microparticles as desired. The result is structures whose response to electromagnetic fields can be precisely planned. “Unlike previous methods, we can generate magnetic polarities directly in complex 3D structures,” says Prof. Xuanhe Zhao of the Department of Mechanical Engineering and Department of Civil and Environmental Engineering .

The YouTube video features prototypes that can perform amazing moves and even move forward. Although the printed material is not very resilient but soft, many areas of application are conceivable, for example for flexibly movable electronic modules or sensitive robotic gripper arms. The scientific report appeared in Nature 558 (2018): Printing ferromagnetic domains for untethered fast-transforming soft materials .