Unmanned Systems Technology 005 | Selex ES Falco UAV | Sense and avoid systems | RCV Engines DF70 | DSEI show report | Fuel cells | CUAV Expo, InterDrone and CUAV Show reports | SLAM

64 U nmanned systems are being deployed in a range of applications that appears to be growing almost exponentially – from the depths of the world’s oceans to the reaches of outer space. A critical challenge with all of these systems though is to supply them with enough fuel energy to give them the payload-carrying capability and endurance to carry out their assigned tasks, and to do so within an overall vehicle design that of necessity has to feature a range of compromises. Although petroleum-based fuels are popular because of their high energy density compared with batteries and other power sources, oil is a material that will ultimately run out and will therefore become increasingly unaffordable for all but the most efficient propulsion systems. This generally means a highly industrialised product, unlike the unmanned vehicles of today. Renewable energy sources such as biomass and solar have yet to prove their reliability in providing uninterrupted (or readily replenished) energy for unmanned use. There is also the issue of energy per unit vehicle mass, which is critical in the design of aerial vehicles in particular, where weight is at a premium. These issues signal the growing importance of using fuel cells to power unmanned systems. In its simplest form, a fuel cell consists of three basic elements – the anode, cathode and the electrolyte (a substance that ionises when dissolved in a suitable Will Roney reports on developments in fuel cell technologies, and the promise they hold for unmanned systems Dec 2015/Jan 2016 | Unmanned Systems Technology Chemistry lessons