Blood sugar-monitoring implant for diabetics is powered by glucose

For a person with diabetes, monitoring blood glucose levels is an everyday hassle, usually involving finger pricks. An emerging alternative might be implantable devices that can automatically monitor levels and alert the patient when attention is needed, but powering these devices is tricky. A new prototype glucose monitor has been designed to power itself from that same glucose in bodily fluids.

Powering implantable devices has long been a challenge – after all, you can’t exactly take it out and pop it on the charger at night like you would your phone. Long-lasting batteries are the main method, but even if they last years surgery is often still required to replace them eventually. Other teams have experimented with wearable devices that charge implants wirelessly from outside the body, or disposable skin patches that monitor blood glucose without needing extra power.

Researchers at King Abdullah University of Science and Technology (KAUST) have now developed a new device that can essentially absorb energy from its environment in the human body. Not only does that remove the charging issue, but it means potentially-toxic materials used in batteries won’t need to be put into the body.

The new device is made entirely of biocompatible polymers, and it not only senses glucose but is powered by it. To do so, it’s made up of an n-type semiconducting polymer coupled to an enzyme called glucose oxidase. When this enzyme reacts with glucose in its surroundings, it extracts electrons from it and then shuttles them through the connected polymer. This can be used to sense glucose levels in fluids such as saliva.