Penn State has announced that a prototype subcutaneous glucose sensor, developed by the electrical engineering and materials science group of professor Craig A. Grimes, will be featured at the Museum of Modern Art’s “SAFE: Design Takes on Risk” exhibit in October in NYC. Some details about the technology behind the device:
The device, which measures about a centimeter by half a centimeter and is about the depth of a thin hair, is composed of an I-shaped backbone crossed by a series of 10 slightly decreasing bars. The shape vaguely resembles a miniature harp.
The backbone and crossbars are made of a magnetorestrictive metallic glass – a material that changes shape with application of a magnetic field and generates a magnetic field when it changes shape – coated with a polymer that reacts to changes in acidity. This coating is then topped with glucose oxidase, the enzyme that reacts with glucose.
The acid sensitive coating makes the device swell or shrink, changing mass depending on the surrounding acidity. The acid that causes the changes comes from the reaction of glucose with glucose oxidase, which produces gluconic acid.
When a magnetic field from the outside is placed near the sensor, the sensor vibrates at a frequency dependent on the mass of the sensor. A magnetic coil can read the magnetic flux of the sensor and determine the amount of glucose in the blood.
The detector, now the size of a modern cell phone, could eventually be packaged in something the size of a wristwatch and the biosensor could be implanted beneath the skin for bloodless monitoring, however, the device is currently not commercially available.