Shapeshifting Microrobots Can Brush and Floss Teeth

by Katherine Unger Baillie

In a proof-of-concept study, researchers from the School of Dental Medicine and School of Engineering and Applied Science shows that a hands-free system could effectively automate the treatment and removal of tooth-decay-causing bacteria and dental plaque. (Illustration: Melissa Pappas)

A shapeshifting robotic microswarm may one day act as a toothbrush, rinse, and dental floss in one.

The technology, developed by a multidisciplinary team at the University of Pennsylvania, is poised to offer a new and automated way to perform the mundane but critical daily tasks of brushing and flossing. It’s a system that could be particularly valuable for those who lack the manual dexterity to clean their teeth effectively themselves.

The building blocks of these microrobots are iron oxide nanoparticles that have both catalytic and magnetic activity. Using a magnetic field, researchers could direct their motion and configuration to form either bristlelike structures that sweep away dental plaque from the broad surfaces of teeth, or elongated strings that can slip between teeth like a length of floss. In both instances, a catalytic reaction drives the nanoparticles to produce antimicrobials that kill harmful oral bacteria on site.

Experiments using this system on mock and real human teeth showed that the robotic assemblies can conform to a variety of shapes to nearly eliminate the sticky biofilms that lead to cavities and gum disease. The Penn team shared their findings establishing a proof-of-concept for the robotic system in the journal ACS Nano.

“Routine oral care is cumbersome and can pose challenges for many people, especially those who have hard time cleaning their teeth” says Hyun (Michel) Koo, a professor in the Department of Orthodontics and divisions of Community Oral Health and Pediatric Dentistry in Penn’s School of Dental Medicine and co-corresponding author on the study. “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.”

Read the full story in Penn Engineering Today.

Hyun (Michel) Koo is a professor in the Department of Orthodontics and divisions of Community Oral Health and Pediatric Dentistry in the School of Dental Medicine, co-director of the Center for Innovation & Precision Dentistry, and member of the Penn Bioengineering Graduate Group at the University of Pennsylvania.

Edward Steager is a senior research investigator in Penn’s School of Engineering and Applied Science.

Koo and Steager’s coauthors on the paper are Penn Dental Medicine’s Min Jun Oh, Alaa Babeer, Yuan Liu, and Zhi Ren and Penn Engineering’s Jingyu Wu, David A. Issadore, Kathleen J. Stebe, and Daeyeon Lee.

This work was supported in part by the National Institute for Dental and Craniofacial Research (grants DE025848 and DE029985), Procter & Gamble, and the Postdoctoral Research Program of Sungkyunkwan University.