Unmanned Systems Technology 012 | AutoNaut USV | Connectors | Unmanned Ground Vehicles | Cobra Aero A33i | Intel Falcon 8+ UAV | Propellers | CES Show report

Power source with no flaws Researchers at the University of Bristol have developed a way to use nuclear waste to generate electricity in a battery (writes Nick Flaherty). The team, led by Prof Tom Scott at the university’s Interface Analysis Centre, has grown a man-made diamond that, when placed in a radioactive field, is able to generate a small electrical current. The diamond can produce a charge simply by being placed close to, or around, a radioactive source. “There are no moving parts involved, no emissions generated and no maintenance required, just direct electricity generation,” said Prof Scott.  “By encapsulating radioactive material inside diamonds, we turn a long-term problem of nuclear waste into a nuclear- powered battery and a long-term supply of clean energy.” The team has demonstrated a prototype battery using nickel-63 as the radiation source but is now working to significantly improve the efficiency of the battery by using radioactive carbon-14. This comes from the graphite blocks used to moderate the reaction in nuclear power plants, and was chosen as a source material because it emits short-range radiation, which is quickly absorbed by any solid material. The actual amount of carbon-14 in each battery has yet to be decided, but one battery with only 1 g of carbon-14 would deliver 15 Joules per day. While this compares with 14,000 J in a day from a 20 g AA battery, the carbon-14 battery would take 5730 years to reach 50% power. “We see these batteries used in situations where it is not feasible to charge or replace conventional batteries,” said Prof Scott. “Obvious applications would be in low-power electrical devices where long life of the energy source is needed, such as pacemakers, satellites, high-altitude drones or even spacecraft.” Other potential applications that have been suggested are for powering GNSS receivers and data recorders. As it is lightweight and robust, the battery could be used to power a GNSS receiver in a UAV separately from its main power supply so that it can be located if it runs out of power. Similarly it could power a ‘black box’ storing flight data for forensic analysis even if the rest of the power system fails. Power supplies