In recent years, hydrogen (H2) has emerged as the best
option for clean energy in our pursuit of an alternative fuel for
mitigating environmental problems such as global warming. Hailed as
‘batteries of the future,’ H2 fuel cells are touted as the fuel for
the future generation. While this is all well and good, there is
one major problem with H2: like every other gas fuel, it is highly
explosive. A minor spark can set off an explosion in the presence
of as low as 4% of H2 leaked into the air, as happened in May 2019
in Gangneung, Korea, and June of the same year at the Uno-X fueling
station in Norway. Therefore, safety is a major concern with
handling of H2 gas; this warrants the sensing of even the smallest
H2 leaks to avoid accidents.