Uncrewed Systems Technology 047 l Aergility ATLIS l AI focus l Clevon 1 UGV l Geospatial insight l Intergeo 2022 report l AUSA 2022 report I Infinity fuel cell l BeeX A.IKANBILIS l Propellers focus I Phoenix Wings Orca

78 A s PEM fuel cell solutions mature, so interest turns increasingly towards optimising their efficiency and minimising the amount of heat wasted. While considerable r&d has gone into countering heat wastage, with advances in that following on, breakthroughs on the side of waste water management have been fewer and farther between. Conventional fuel cells will most often remove water by blowing air through the cell layers, extracting the water via entrainment. In many cases, there are few problems with this – UGVs, USVs and low-altitude UAVs for instance can simply take in the air around them and expel the water through an exhaust with no harmful effect on the vehicle or its surroundings. That is impossible for many other types of uncrewed vehicle though. UUVs and spacecraft for example have to keep much of their componentry pressurised, and HALE or HAPS-type UAVs cannot depend on ambient air owing to altitudes they fly at, while autonomous rovers and rotorcraft operating on other worlds would suffer from a mixture of these issues. Solutions to these issues have been tried. For example, some fuel cells have used artificial air – combinations of oxygen and nitrogen – to remove the water. But such approaches are energy- inefficient and often require additional fans, blowers and complex venting systems for the blending, delivery and expulsion of the nitrogen-oxygen gas. An alternative approach uses stores of hydrogen and oxygen to remove the water produced by the fuel cell. This requires circulation systems for the gases, and an external means A fuel cell that needs no ambient air to remove its water makes it ideal for underwater and space applications, a point not lost on this company. Rory Jackson reports No-air power December/January 2023 | Uncrewed Systems Technology For many years, Infinity Fuel Cell and Hydrogen has developed highly customised PEMFC systems in small quantities for uncrewed space and naval systems, and is now transitioning towards batch production of families of its products (Images courtesy of Infinity Fuel Cell and Hydrogen)