Implantable autonomous battery
Researchers at Joseph Fourier University in Grenoble (France) for the first time implanted a glucose-powered power supply element into an animal's body. In a living organism, glucose is an almost inexhaustible source of energy, therefore, unlike existing power sources for implants, a new battery does not need to be surgically removed in order to be replaced.
The principle of operation of the device is based on enzymatic catalysis of the reaction of interaction of glucose and oxygen contained in the tissues of the body. Earlier attempts to implant such elements in animals ended in failure due to the fact that an acidic environment was required for the functioning of enzymes, or their activity was suppressed by charged particles contained in the extracellular fluid. The authors overcame this problem by fixing the enzymes inside the electrodes, which are discs made of pressed graphite and located inside dialysis bags. Such a device provides access of glucose and oxygen to enzymes that catalyze the glucose oxidation reaction accompanied by the release of electricity.
The authors implanted such batteries into the abdominal cavity of two rats. The maximum power of the device in the body reached 6.5 microvatts, which is slightly less than the 10 microvatts needed to maintain the heart rate drivers. After 11 days, the battery in the abdominal cavity of one of the rats still maintained a voltage of about two microwatts, while the byproducts of glucose metabolism were recorded in the urine of the second rat for three months, indicating partial preservation of the device's operability, at least during this time. Experts believe that the work done by the authors is a breakthrough in the development of implantable biological power sources.
The battery developed by the authors can be used to provide power to a wide range of devices, such as nerve and bone growth stimulators, devices for controlled drug delivery and biosensors. However, to do this, it is necessary to increase the efficiency of electron transfer between enzymes and electrodes.
In the near future, the developers plan to address this problem. After that, they will work on improving the design of the device, replacing the materials used in its manufacture with biocompatible ones and testing a new version of the nutrient element on larger animals for a longer time. Experts believe that if the industry shows interest in the technological development of biological nutrition elements, they can be brought to the production stage in the near future.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on the materials of TechnologyReview: Power from Glucose.
20.05.2010