Global Sources
EE Times-Asia
Stay in touch with EE Times Asia
?
EE Times-Asia > Sensors/MEMS
?
?
Sensors/MEMS??

Tooth tattoo sensor able to measure bacteria levels in mouth

Posted: 20 Nov 2012 ?? ?Print Version ?Bookmark and Share

Keywords:oral sensor? grapheme? clinical testing?

Nanoscientist Michael McAlpine from Princeton University and bioengineer Fiorenzo Omenetto, David Kaplan and Hu Tao from Tufts University have developed a new ultra-thin, flexible oral sensor.

Attached temporarily to a tooth, the sensor dubbed the "tooth tattoo" can measure bacteria levels in the mouth and could one day help dentists fine-tune treatments for patients with chronic periodontitis, for example, or even provide a window on a patient's overall health.

The sensor is relatively simple in its construction, says McAlpine. It's made up of just three layers: a sheet of thin gold foil electrodes, an atom-thick layer of graphite known as graphene and a layer of specially engineered peptides, chemical structures that "sense" bacteria by binding to parts of their cell membranes.

Tooth Tattoo

A diagram for the Tooth Tattoo Oral Sensor.

"We created a new type of peptide that can serve as an intermediary between bacteria and the sensor," says McAlpine. "At one end is a molecule that can bond with the graphene, and at the other is a molecule that bonds with bacteria," allowing the sensor to register the presence of bacteria, he says. Because the layers of the device are so thin and fragile, they need to be mounted atop a tough but flexible backing in order to transfer them to a tooth. The ideal foundation, McAlpine says, turns out to be silk!a substance with which Kaplan and Omenetto have been working for years.

By manipulating the proteins that make up a single strand of silk, it's possible to create silk structures in just about any shape, says Omenetto, a professor of biomedical engineering at Tufts. Since 2005, he's created dozens of different structures out of silk, from optical lenses to orthopedic implants. Silk is "kind of like plastic, in that we can make (it) do almost anything," he says. "We have a lot of control over the material. It can be rigid. It can be flexible. We can make it dissolve in water, stay solid, become a gel!whatever we need."

Omenetto, Kaplan and Tao created a thin, water-soluble silk backing for McAlpine's bacterial sensor!a film that's strong enough to hold the sensor components in place, but soft and pliable enough to wrap easily around the irregular contours of a tooth. To apply the sensor, McAlpine says, you need only to wet the surface of the entire assembly!silk, sensor and all!and then press it onto the tooth. Once there, the silk backing will dissolve within 15 or 20 minutes, leaving behind the sensor, a rectangle of interwoven gold and black electrodes about half the size of a postage stamp and about as thick as a sheet of paper. The advantage of being attached directly to a tooth means that the sensor is in direct contact with bacteria in the mouth!an ideal way to monitor oral health.

Because the sensor doesn't carry any onboard batteries, it must be both read and powered simultaneously through a built-in antenna. Using a custom-made handheld device about the size of a TV remote, McAlpine's team can "ping" that antenna with radio waves, causing it to resonate electronically and send back information that the device then uses to determine if bacteria are present.

Right now the sensor can only detect gram-negative bacteria, the general class of bacteria responsible for periodontal disease. Once its detection ability is honed, it eventually might help dentists track exactly when and where certain bacteria are present in the mouth so that they can develop customised treatment plans for patients with chronic periodontal disease.


1???2?Next Page?Last Page



Article Comments - Tooth tattoo sensor able to measure ...
Comments:??
*? You can enter [0] more charecters.
*Verify code:
?
?
Webinars

Seminars

Visit Asia Webinars to learn about the latest in technology and get practical design tips.

?
?
Back to Top