Shapeshifting microrobots may one day act as a toothbrush, rinse, and dental floss in one. The technology, developed by a multidisciplinary team, including Penn Dental Medicine’s Michel Koo, 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 shapeshifting 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, which is part of the Center for Innovation and Precision Dentistry (CiPD), 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 Koo, a professor in the Department of Orthodontics and divisions of Community Oral Health and Pediatric Dentistry at Penn Dental Medicine, Co-Director of the CiPD, 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.”
“Nanoparticles can be shaped and controlled with magnetic fields in surprising ways,” says 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.”
