Tiny robots have the potential to do things like deliver targeted drugs inside the body, but controlling their position and movements remotely has been a challenge. Now, a team of researchers has come up with a new way to use magnets to fold tiny robots into different shapes–allowing these remote-controlled micro-machines to do things like grasp objects and crawl around. Magnets have been used to control bots before but these other magnetic minions were stiff because of the materials used to build them. To create a millimeter-scale robot capable of feats of flexibility, the researchers embedded magnetic particles of the element neodymium in pliable material. The researchers then used a pair of powerful magnets to flip the polarity of the neodymium particles in different sections of the robot and UV light to lock them into place. By creating segments of the mini-robots that were attracted or repelled in different directions, the researchers could create complex 3D movements like grasping, crawling, and swimming. Researchers designed a few different robots, each with different abilities This robot is built for gripping objects– when the magnetic field is activated, the robot’s arms fold up, like a hand closing around an apple. It can even curl up into a ball and roll around, taking wireless commands from a scientist using a video game controller. This robot is built like an accordion, and moves around like an inchworm. This robot is robot has a number of paddles, which allows it to crawl across surfaces like an insect. The most obvious applications for these tiny magnetic robots are medical, but they could also be used to staff miniaturized factories building even smaller goods. Researchers are hoping to replace neodymium in future versions of these robots. Like lead or mercury, neodymium is a toxic heavy metal that would need to be removed from inside the body if the bots were being used to assist a surgery or deliver drugs. Researchers believe less toxic metals can still work, but may require stronger magnets to be manipulated. The speedy, low-cost manufacturing process researchers developed for these robots could position them for widespread success in the medical world.