Carbon-14 is one of the naturally occurring radioactive isotopes and is widely used for radiocarbon dating. Its half-life is 5700 years. An atomic battery based on it, which was invented by scientists from the UK, can last approximately this long and even longer.
Image source: University of Bristol
During the radioactive decay of 14C, electrons and positrons are formed – this is the so-called betavoltaic. This phenomenon has long been widely used in the manufacture of radioisotope batteries. The electrons are captured by semiconductor junctions adjacent to the zone boundary next to the radioactive material, and then everything is like in conventional solar panels, only without photons – electric current begins to flow through the junctions.
Such batteries provide microwatts of power, but this is also needed in many areas. Conditionally eternal batteries will be able to power implants, which will no longer bother patients in terms of the need to periodically replace power sources, as well as maintenance-free electronics – beacons, radio tags, sensors and microprobes in space. In short, there is a demand for nuclear batteries and it is growing.
The innovation of scientists from the University of Bristol and the UK Atomic Energy Authority (UKAEA) was the development of a technology for artificially creating a diamond shell around an isotope, for which plasma spraying was used. Diamond is neutral, which is necessary for installing such batteries in the human body to power implants.
For humans, radiation from the 14C isotope will be safe, since this element is the second source of residual radiation in the body after potassium-40. Actually, the accumulation of 14C by all organic matter existing on Earth allows it to be used for radiocarbon dating of antiquities. But that’s another story.