Medical implants will soon be autonomous in terms of energy

Researchers have developed a miniature enzymatic bio-battery capable of driving an electronic chip. The perspective of being able to operate miniaturized medical sensors using our own body fluids seems to be within reach.

Drawing on the energy of physiological fluids to feed bio-medical sensors is the challenge that an international team1Paul Pascal Research Center (CNRS), Institute of Molecular Sciences (CNRS/Université de Bordeaux/Bordeaux INP Aquitaine), Max-Planck Institute for Intelligent Systems, Institute for Microelectronics has managed to meet, using a miniaturized enzymatic bio-battery. In such a device, the battery is composed of two electrodes modified using enzymes: the first electrode plays the role of the anode by oxidizing glucose, while the second serves as a cathode and reduces oxygen. Researchers integrated their miniature bio-battery into an electronic chip especially designed to be driven by this source of energy. The functioning of this integrated system was then tested under conditions of temperature and pH similar to those that prevail in the human body. The electronic chip could be kept active for several hours by a single drop of glucose.

Experiments carried out in parallel in human blood and in an animal model also demonstrated the biocompatibility of this autonomous sensor. These studies open new perspectives for multiple applications in the medical sector. For example, implanted under the skin of diabetics, this type of device could allow the level of blood glucose to be measured constantly, which would make the daily control of their glycaemia much less constraining.

Lab on Chip, April 2017