Researchers at the University of Pennsylvania have developed prototype teeth-cleaning devices that use microrobots made of iron oxide nanoparticles. With the push of a button, magnets guide the microrobot swarms to form bristles for brushing or an elongated thread for flossing. Notably, the nanoparticles are approved for human consumption by the U.S. Food and Drug Administration.

Two distinct devices are being tested: a mouthguard and a toothbrush. Upon activation, the device distributes a solution of microrobots and hydrogen peroxide into the mouth. The iron oxide nanoparticles kill bacteria and break down plaque more effectively than the disinfectant alone. In testing, researchers have removed 100 percent of plaque from a 3D printed model of human teeth and gums, and achieved an 80 percent success rate in animal testing. Work continues to increase the system’s effectiveness and shorten the cleaning time, which currently ranges from five to 10 minutes.