Powering medical implants with blood sugar

Researchers have developed a thin-film fuel cell made from ceramics that could power medical implants using the body’s own supply of glucose

Spotted: Glucose is the body’s main source of energy. It comes from the food we eat and is carried to all of the cells in the body. Now, a group of engineers at MIT’s Department of Materials Science and Engineering (DSME) and the Technical University of Munich have designed a new type of fuel cell that can convert glucose directly into electricity. In the future, the device could be incorporated into medical implants, allowing these implants to be powered directly from the body itself.

The fuel cell uses an electrolyte made from ceria, a ceramic material with high ion conductivity and biocompatibility. It also retains electrochemical properties at both high temperatures and at small scale. It will work at the scale of just 400 nanometres thick, around one-hundredth the diameter of a human hair. The researchers envision using the ceramic in the form of a film or coating that could be wrapped around implants.

The team created the cells by sandwiching the electrolyte between an anode and cathode made of platinum. The cell will generate between 43 and 80 microwatts per square centimetre – the highest power density of any glucose fuel cell to date. This is also high enough to power implantable medical devices.

Jennifer L.M. Rupp, a DMSE visiting professor and associate professor of solid-state electrolyte chemistry at Technical University Munich in Germany explains that, “It is the first time that proton conduction in electroceramic materials can be used for glucose-to-power conversion, defining a new type of electrochemistry. It extends the material use-cases from hydrogen fuel cells to new, exciting glucose-conversion modes.” 

Medical implants have come a long way, powered by some astounding innovations. Other recent advances in powering implants include a bio-friendly supercapacitor system that charges up using electrolytes from biological fluids such as blood and urine, and a smart tattoo that can track electrical activity in the body.