Implantable Ultra-Thin Fuel Cell Runs on the Body’s Own Glucose

The sugar we absorb via the food we eat gets converted into glucose and provides fuel to power the cells in our bodies. Engineers from MIT and the Technical University of Munich have developed an ultra-thin fuel cell that can tap into that energy to power implants and sensors inside the human body. According to the researchers, the fuel cell is smaller than other proposed cells, measuring 400 nanometers thick, and can generate around 43 microwatts per square centimeter of electricity. Moreover, it can withstand temperatures up to 600 degrees Celsius, allowing them to handle the sterilization process before being implanted.

The device is made from ceramic, enabling it to retain its electrochemical properties even at high temperatures and miniature scales. The engineers feel the new design could be made into ultra-thin films or coatings and wrapped around implants to passively power electronics using the body’s abundant supply of glucose.

“Glucose is everywhere in the body, and the idea is to harvest this readily available energy and use it to power implantable devices,” states Philipp Simons, who developed the design as part of his PhD thesis in MIT’s Department of Materials Science and Engineering. “In our work, we show a new glucose fuel cell electrochemistry.

The cell was created using three layers: an anode, an electrolyte, and a cathode. The anode reacts with the sugar in bodily fluids, releasing a pair of protons and a pair of electrons during the process. The electrolyte then takes the electrons to an external circuit, where it’s used to power an electronic device. Meanwhile, the protons go through the cathode, where it reacts with oxygen to form a harmless water byproduct in much the same fashion as a hydrogen fuel cell, minus the high heat. The ceramics used in the design are non-toxic, cheap to manufacture, and inert to the body’s internal chemistry, which helps mitigate rejection after being implanted inside the body.