Tiny Robots Could One Day Replace Your Toothbrush

Researchers from the University of Pennsylvania's School of Dental Medicine and School of Engineering and Applied Science have released a proof-of-concept study detailing a novel approach to hands-free oral care. The microbots can change shape to form bristles for brushing or slide between the teeth for flossing while releasing an antimicrobial substance to eliminate harmful bacteria. It’s an automated system that could help the disabled and those with limited mobility.

“Routine oral care is cumbersome and can pose challenges for many people, especially those who have a hard time cleaning their teeth,” explains Professor Hyun Koo at Penn’s School of Dental Medicine. “You have to brush your teeth, then floss your teeth, then rinse your mouth; it’s a manual, multistep process. The big innovation here is that the robotics system can do all three in a single, hands-free, automated way.”

Prototypes of the microbots were designed using iron oxide nanoparticles that exhibit both catalytic and magnetic properties. The tiny robots function using a magnetic field to direct their motion and configuration to form either bristle-like structures that brush away dental plaque from the broad surfaces of teeth or long strings that can slip between teeth like floss. In both examples, a catalytic reaction drives the nanoparticles to produce antimicrobials that kill harmful oral bacteria.

The microbot system is also fully programmable, allowing the researchers to use variations in the magnetic field to tune the motions of the robots as well as control bristle stiffness and length. They even found that the tips of the bristles could be made firm enough to remove biofilms but soft enough to avoid damaging the gums. The research team is currently optimizing the robots’ motions and looking at ways to deliver the microbots via mouth-fitting devices.