Shapeshifting microrobots can brush and floss teeth
Arranged in bristle-like structures, a robotic microswarm of iron oxide nanoparticles developed by a team from the University of Pennsylvania effectively cleaned plaque from teeth. The nanoparticles have both magnetic and catalytic properties; catalyzed hydrogen peroxide produced free radicals that eliminated tooth decay-causing pathogens as well. Credit: Minjun Oh/Penn Dental Medicine

One day a shapewarm robotic microswarm will act as a toothbrush, rinse, and dental floss. The technology developed by the University of Pennsylvania is poised to offer a new and automated way to perform the mundane but important tasks of brushing and flossing. It's a system that could be useful for people who don't have a lot of manual dexterity.

Iron oxide particles have both magnetic and catalytic activity. Researchers could use a magnetic field to create bristle-like structures that sweep away dental plaque from the broad surfaces of teeth or strings that can slip between teeth. There are two instances in which a catalyst drives the nanoparticles to kill harmful oralbacteria.

Experiments using this system on mock and real human teeth show that the robotic assembly can conform to a variety of shapes to eliminate sticky biofilms. A proof-of-concept for the robotic system was created by the Penn team.

"Routine oral care is cumbersome and can pose challenges for many people, especially those who have hard time cleaning their teeth," says a professor in Penn's School of Dental Medicine and co-cor. It's a multi-step process, and you have to brush your teeth, floss, and rinse your mouth. The robotic system can do all three in a single way.

Edward Steager is a senior research investigator in Penn's School of Engineering and Applied Science and co-corresponding author. Like flossing, we form bristles that can extend, sweep, and even transfer across a space. It's similar to how a robotic arm might clean a surface. The system can beprogrammed to do certain tasks.

Shapeshifting microrobots can brush and floss teeth
An infographic explains the magnetic and catalytic properties of the iron oxide nanoparticles and their assembly into bristle and floss-like forms. Credit: Melissa Pappas/Penn Engineering

Oral care technology is being disrupted.

The design of the toothbrush hasn't changed for thousands of years.

The fundamental concept of the 'bristle-on-a-stick format' has not changed. It's a technology that has been around for a long time.

Several years ago, Penn researchers within the Center for Innovation & Precision Dentistry took steps toward a major disruption using this microrobotics system.

They came up with their innovation by chance. Both Penn Engineering and Penn Dental Medicine had research groups interested in iron oxide particles. The group was interested in the activity of the particles. They can kill tooth-decay-causingbacteria and degrade dental plaque by releasing hydrogen peroxide. Dean Kumar and Professor Kathleen Stebe were working on building blocks of magnetically controlled microrobots.

The current work was supported by Penn Health Tech and the National Institute of Dental and Craniofacial Research.

If you have straight teeth, it will adapt to different surfaces. The system can adjust to all the nooks andTrademarkias

The researchers were able to improve the motions of the microrobots. They used 3-D printed tooth models from the dental clinic to test the performance of the microrobots. They tried the microrobots on real human teeth that were mounted in such a way as to mimic the position of teeth in the mouth.

The researchers found that the microrobotics system could clear all the pathogens from the surfaces. Testing of the bristle formations on an animal model showed that they did not harm the gum tissue.

The team's roboticists and engineers used variations in the magnetic field to tune the motions of the microrobots. The researchers found that the tips of the bristles were soft enough to not hurt the gums.

The researchers say that the system is gentle enough for clinical use, but also personalized, able to adapt to a patient's unique topographies.

The Penn team is looking at different ways to deliver the microrobots through mouth-fitting devices.

They want to help patients.

"We have technology that is as effective as brushing and flossing your teeth, but doesn't require manual dexterity." We would love to see this help the elderly and people with disabilities. Current oral health care will be disrupted by it.

More information: Min Jun Oh et al, Surface Topography-Adaptive Robotic Superstructures for Biofilm Removal and Pathogen Detection on Human Teeth, ACS Nano (2022). DOI: 10.1021/acsnano.2c01950 Journal information: ACS Nano