Magnetically Activated Micromachines

"Magnetically Activated Micromachines to Operate Remotely Inside Body":

Engineers at MIT have created a class of magnetically activated bug-like microdevices that may foreshadow remote-controlled surgical tools and externally powered heart-assist pumps. These interesting devices have an origami-like look and a variety of them have been built that crawl, jump, grasp, and do other things. They’re actually printed from soft materials that have ferromagnetic nanoparticles within their interior, allowing a magnet to manipulate them.