The effects of various tensile velocities on nanocrack formation were studied.
A tunable nanocrack was created by mechanical stretching/compression cycles.
The tensile velocity was found to have a significant effect on the crack density.
A low detection limit of 500 ppm of H2 in air was demonstrated.
Narrow nanocracks (w: 55–100 nm) and high crack density provides enhanced sensing properties in air.