Ultrathin fuel cell uses the body's own sugar to generate electricity

Glucose is the sugar we absorb from the foods we eat. It is the fuel
that powers every cell in our bodies. Could glucose also power
tomorrow’s medical implants?
Engineers at MIT and the Technical University of Munich think so
(https://bit.ly/3szNk72). They have designed a new kind of glucose
fuel cell that converts glucose directly into electricity. The device
is smaller than other proposed glucose fuel cells, measuring just
400 nanometers thick, or about 1/100 the diameter of a human hair.
The sugary power source generates about 43 microwatts per square
centimeter of electricity, achieving the highest power density of
any glucose fuel cell to date under ambient conditions.
The new device is also resilient, able to withstand temperatures up
to 600 degrees Celsius. If incorporated into a medical implant, the
fuel cell could remain stable through the high-temperature
sterilization process required for all implantable devices.
The heart of the new device is made from ceramic, a material that
retains its electrochemical properties even at high temperatures and
miniature scales. The researchers envision the new design could be
made into ultrathin films or coatings and wrapped around implants
to passively power electronics, using the body’s abundant glucose
supply.
“Glucose is everywhere in the body, and the idea is to harvest this
readily available energy and use it to power implantable devices,”
says Philipp Simons, who developed the design as part of his PhD
thesis in MIT’s Department of Materials Science and Engineering
(DMSE). “In our work we show a new glucose fuel cell
electrochemistry.”
“Instead of using a battery, which can take up 90 percent of an
implant’s volume, you could make a device with a thin film, and
you’d have a power source with no volumetric footprint,” says
Jennifer L.M. Rupp, Simons’ thesis supervisor and a DMSE visiting
professor, who is also an associate professor of solid-state
electrolyte chemistry at Technical University Munich in Germany.
Simons and his colleagues detail their design today in the journal
Advanced Materials. Co-authors of the study include Rupp, Steven
Schenk, Marco Gysel, and Lorenz Olbrich.