Shapeshifting microbots may be the future of oral hygiene

By Danny Halpin via SWNS

People may one day abandon their toothbrush and clean their teeth with a shapeshifting robotic microswarm which scrubs, rinses and flosses all in one.

Scientists have developed the technology as a way to automate the necessary chore of daily life to make it easier for older people and those with disabilities to keep their teeth clean.

The microrobots are made of iron oxide nanoparticles that create a chemical reaction in the mouth, releasing antimicrobials that kill off plaque.

They are directed using a magnetic field and can shift into various shapes, forming bristle-like structures that can sweep away plaque from the broad surfaces of the teeth or elongated strings that can slip between the gaps like floss.

Experiments on fake and real human teeth saw the robots eliminate nearly all of the biofilms that lead to cavities and gum disease.

The system is fully programmable in that the magnetic field can be tuned to control the motions of the microbots and the stiffness and length of the bristles.

Researchers say it can be adapted to fit the shape of each person’s mouth, cleaning the plaque without damaging the gums.

Professor Hyun Koo, an orthodontist from the University of Pennsylvania and co-corresponding author on the study, said: “Routine oral care is cumbersome and can pose challenges for many people, especially those who have hard time cleaning their teeth.

“You have to brush your teeth, then floss your teeth, then rinse your mouth; it’s a manual, multi-step process.

“The big innovation here is that the robotics system can do all three in a single, hands-free automated way.

“It doesn’t matter if you have straight teeth or misaligned teeth, it will adapt to different surfaces. The system can adjust to all the nooks and crannies in the oral cavity.”

Dr. Edward Steager, senior research engineer also at University of Pennsylvania, said: “Nanoparticles can be shaped and controlled with magnetic fields in surprising ways.

“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 research, published in the journal ACS Nano, arose from a serendipitous collaboration between the engineering and dental departments at the university, who were interested in the iron oxide nanoparticles for different reasons.

Prof Koo’s team were interested in the ability of the nanoparticles to create chemical reactions whereas Steager’s group were exploring their use as building blocks for magnetically controlled microbots.

The collaborators combined their work to create electromagnetically-controlled microbots that change shape and release antimicrobials that clean teeth.

It is a radical departure from the tried and tested bristle-on-a-stick format people have used for millennia, the researchers say.

In tests, they first used 3D-printed models before trying the robots on real teeth. They also used an animal model and found the bristles formations did not harm the gum tissue.

The scientists are eager to see their technology help patients and are moving their invention towards the clinic by optimizing the robots’ motions and considering different ways of delivering them to the mouth through various devices.

Prof Koo said: “We have this technology that’s as or more effective as brushing and flossing your teeth but doesn’t require manual dexterity.

“We’d love to see this helping the geriatric population and people with disabilities. We believe it will disrupt and majorly advance oral health care.”