Researchers have made a miniature device that can quickly detect hydrogen leaks.
Such a device might be useful in future cars powered by fuel cells since hydrogen
concentrations above a few percent can be explosive. The same device also could be
useful for regulating hydrogen concentrations in the cars' engines.
Most hydrogen sensors rely on thin palladium wires, which decrease their
conductivity within seconds or minutes after adsorbing molecules of the gas.
Reginald M. Penner of the University of California at Irvine and his colleagues
suspected that sensors made with much smaller wires would operate in the same way
but more quickly.