The ultrathin device relies on a ceramic material as an electrolyte and platinum anodes/cathodes. The researchers were able to place just over 150 fuel cells onto a chip and the individual fuel cells produce a peak voltage of approximately 80 millivolts when a glucose solution was passed over them, placing them in range of the power requirements for many implanted devices.
Implantable medical technologies beckon us towards a whole new world of real-time health monitoring and advanced treatment. From diabetes to neuromodulation, the potential applications are near endless. However, there is always the pesky question of powering such implants.
Batteries eventually run out of charge, requiring removal and replacement, whereas wires that pierce the skin are cumbersome and pose an obvious infection risk. Wireless charging technologies are an alternative, but are largely in their infancy, and would likely still require an external charging device worn on the skin.
This latest technology aims to obtain power from our own bodies, and specifically from the glucose in our blood, avoiding the need for batteries, wires, or external chargers. “Glucose is everywhere in the body, and the idea is to harvest this readily available energy and use it to power implantable devices,” said Philipp Simons, a researcher involved in the study. “In our work we show a new glucose fuel cell electrochemistry.”
The new devices are incredibly thin at 400 nanometers, which is approximately 1/100th the diameter of a human hair. Interestingly, the fuel cells are also highly temperature resistant, and can withstand up to 600 degrees Celsius without being damaged, allowing them to be sterilized using heat before implantation.
The electrolyte within the new fuels cells is ceramic and is made using a material called ceria, which has the advantages of mechanical stability, biocompatibility, and ion conductivity, and it is already widely used in hydrogen fuel cells. “Ceria is actively studied in the cancer research community,” said Simons. “It’s also similar to zirconia, which is used in tooth implants, and is biocompatible and safe.”
According to medgadget.com