Under my skin

A US researcher has developed a microscopic colour-changing sensor that can be placed just under the skin to allow a user to visibly monitor glucose levels.

Miklos Gratzl, the associate professor of biomedical engineering and researcher at the Case School of Engineering, has developed a microscopic colour-changing sensor that can be placed just under the skin to allow a user to visibly monitor glucose levels and other bodily fluid levels.

The colour of the tiny sensor, which is smaller than the tip of a pencil, gradually changes from orange (low glucose levels) to green and then to dark blue as levels increase. A deep, dark blue signifies the highest glucose level that can occur in diabetics.

Gratzl and his colleague Koji Tohda, a biomedical engineering researcher at Case, believe the sensor could improve the quality of life of diabetics.

“Many diabetics could greatly benefit from this technology, freeing them from having to take samples from their fingers several times a day to monitor blood sugar levels,” Gratzl said.

“The sensor could also help doctors with close monitoring of electrolytes, metabolites and other vital biochemicals in the body, primarily those of critically ill patients.”

The sensor, which is one to two millimetres long and 100 to 200 micrometers wide, penetrates the skin easily and painlessly so users may insert or reinsert it themselves when needed. It can be monitored by eyesight and by electronic telemetry using a watchlike device worn by the person for data processing.

Gratzl says lab testing and in vivo testing of the sensor in laboratory animals has been going well. He also reports the sliver sensor could be ready for human testing within six months.

“So far, the sensor is performing beyond expectation in preliminary laboratory tests,” Gratzl said.

“Over the years, there has been a lack of good, quality devices for diabetics to monitor glucose – something they must do every day of their lives – devices that are reliable, relatively low-cost and minimally invasive.”