“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.”

“Nanoparticles can be shaped and controlled with magnetic fields in surprising ways,” added Edward Steager, a senior research investigator in Penn’s School of Engineering and Applied Science and co-corresponding author.

“We form bristles that can extend, sweep, and even transfer back and forth across a space, much like flossing. The way it works is similar to how a robotic arm might reach out and clean a surface. The system can be programmed to do the nanoparticle assembly and motion control automatically.”

The team is set to revolutionize the traditional but old-fashioned toothbrush. “The design of the toothbrush has remained relatively unchanged for millennia,” explained Koo.

While adding electric motors elevated the basic “bristle-on-a-stick format,” the fundamental concept has remained the same. “It’s a technology that has not been disrupted in decades.”

The new development consists of microrobots that are iron oxide nanoparticles that have both catalytic and magnetic activity. The team would use a magnetic field to direct their motion and configuration of these nanoparticles to form either bristlelike structures that sweep away dental plaque or elongated strings that can slip between teeth like a length of floss. In both cases, a catalytic reaction drives the nanoparticles to produce antimicrobials that kill harmful oral bacteria on site.