High-Sensitivity Hydrogen Detection: Hydrogen-Induced Swelling of Multiple Cracked Palladium Films on Compliant Substrates

Hydrogen sponge: The reversible swelling of palladium–nickel alloys upon hydrogen absorption mechanically closes nanogaps in multiple cracked Pd–Ni films on elastomeric substrate allowing for the electric current to flow across (see picture). When the hydrogen is removed the elastomer elastically returns to its original state reopening numerous potential break junctions along each crack