Power from the people
October 18, 2011 | Source: BBC News
Scientists at Joseph Fourier University of Grenoble have built a biofuel cell that uses glucose and oxygen at concentrations found in the body to generate electricity.
They are the first group in the world to demonstrate their device working while implanted in a living animal. Within a decade or two, biofuel cells may be used to power a range of medical implants, from sensors and drug delivery devices to entire artificial organs.
Glucose and oxygen are both freely available in the human body, so hypothetically, a biofuel cell could keep working indefinitely.
The electrodes are made by compressing a paste of carbon nanotubes mixed with glucose oxidase for one electrode, and glucose and polyphenol oxidase for the other. The electrodes have a platinum wire inserted in them to carry the current to the circuit. Then the electrodes are wrapped in a special material that prevents any nanotubes or enzymes from escaping into the body.
Finally, the whole package is wrapped in a mesh that protects the electrodes from the body’s immune system, while still allowing the free flow of glucose and oxygen to the electrodes. The whole package is then implanted in the rat.