The effect of dislocations on crack propagation in wrinkled gold film deposited on polydimethylsiloxane.

Crack propagation in a wrinkled thin film of gold deposited on polydimethylsiloxane (PDMS) was affected by the presence of folding defects—the ripple dislocations. The ripple pattern, ripple dislocations, and the crack were simultaneously formed after the tensile load applied on the PDMS substrate was removed. The crack, however, was unstable and propagated forward. The propagation rate increased when the crack passed by the ripple dislocations, but less significantly when it advanced near a ripple dislocation dipole. Such crack dislocation interaction implies that the ripple dislocation has an internal stress field. The measured data of the rate process were analyzed based on the theory of fracture mechanics, and an empirical relationship between the crack velocity and the crack extension force was presented. [ABSTRACT FROM AUTHOR]