Through a new technology developed in Oregon State University, those who are suffering from type 1 diabetes may later monitor their blood glucose levels without the need of puncturing the skin. All it takes is a small transparent blood glucose sensor embedded in the patient’s contact lens.
The sensor is built around the IGZO FET, which is short for indium gallium oxide field effect transistor. It is an amorphous nanostructured transistor that is capable of sensing small variations in glucose levels in bodily fluids such as tears.
Juvenile diabetes, for which type 1 diabetes was once known, is a disease associated with glucose levels in the blood which may lead to complications such as kidney failure, blindness and even heart diseases. Patients with type 1 diabetes need their blood glucose levels monitored and maintained at the right levels.
The IGZO FET sensor will be able to send information regarding the patient’s glucose levels in real-time. The data will be sent to ta wearable pump which will be in-charged of supplying insulin and glucagon – the hormones that regulate blood glucose levels. These hormones are regularly released by the pancreas of people without diabetes.
Greg Herman, author of this research study, is confident that their transparent sensors are truly working. Their next step is to improve on the communication side of the project. “We [also] want to use the entire contact lens as real estate for sensing and communications electronics,” he adds.
Herman is a professor of chemical engineering at OSU. In the future, he wants to detect not only glucose levels but other chemicals present in human tears such as stress hormones and uric acid. “We can monitor many compounds in tears – and since the sensor is transparent, it doesn’t obstruct vision; more real estate is available for sensing on the contact lens.”
The IGZO FET was Herman’s choice because of its closely packed, hexagonal, nanostructured network. This results from complimentary patterning techniques such as colloidal nanolithography and electrohydrodynamic printing which may lead to cheaper production.
Herman sees several issues with Google’s glucose-monitoring contact lens. One is that the amperometric sensor must be planted on the side of the contact lens. “Another issue is that the signal is dependent on the size of the sensor and you can only make it so small or you won’t be able to get a usable signal. With an FET sensor, you can actually make it smaller and enhance the output signal by doing this.”
With this new technology, Herman sees a new and improved way in managing glucose levels. Instead of using blood droplets on glucose strips to monitor blood sugar, the patient would only look at their phones since the device directly communicates via radio.
Cancer detection would be the next step for the transparent FET sensors. The high sensitivity of the sensor enables it to measure biomarkers of cancer risk. Other health monitoring aspects that can be sensed are oxygen levels and pulse rate.
More information can be found at: Oregan State University.