Wearable sensor collects glucose from cells between hair follicles

Scientists from the University of Bath in the U.K. have developed a non-invasive, adhesive patch capable of accurately measuring glucose levels through the skin without a blood test, according to a study published April 9 in Nature Nanotechnology.

Diabetic patients face a routine of finger pricks to measure blood glucose levels, but researchers have developed this low-cost wearable sensor to measure glucose levels. In the study, researchers explained the development of the wearable and its accuracy in tracking glucose levels.

"A non-invasive—that is, needle-less—method to monitor blood sugar has proven a difficult goal to attain,” said Richard Guy. “The closest that has been achieved has required either at least a single-point calibration with a classic 'finger-stick,’ or the implantation of a pre-calibrated sensor via a single needle insertion. The monitor developed at Bath promises a truly calibration-free approach, an essential contribution in the fight to combat the ever-increasing global incidence of diabetes."

The wearable patch sits on the skin and collects glucose in reservoirs from the fluid from the cells between hair follicles. The fluid is then examined on the patch’s sensor using a small electric current. Results are compiled within 15 minutes and sent to a mobile phone or smartwatch for easy viewing.

“The specific architecture of our array permits calibration-free operation, and it has the further benefit of allowing realization with a variety of materials in combination,” said Adelina Ilie, from the Department of Physics. “We utilized graphene as one of the components as it brings important advantages: specifically, it is strong, conductive, flexible, and potentially low-cost and environmentally friendly. In addition, our design can be implemented using high-throughput fabrication techniques like screen printing, which we hope will ultimately support a disposable, widely affordable device."

In the study, researchers evaluated the accuracy of the device on both pig skin and healthy human participants. The wearable showed it could accurately track glucose levels in ranges seen in diabetic human patients on the pig skin while also showing its capability to track blood glucose long-term in healthy human participants.