Formation and mechanism for stress induced micropattern of polydimethylsiloxane

A compressively stressed poly (dimethylsiloxane) (PDMS) film with a sputtered gold film can buckle owing to the difference between the Young’s modulus of the PDMS film and that of the gold film. The instability of stress is observed at the interface between materials with different Young’s modulus. The experiment conducted in this study revealed the important factors that affect the evolution of strips at certain angles at which tensile stress is applied to the elastomer with a ripple pattern. Strips cannot withstand shear stress applied in two different directions simultaneously, resulting in the formation of grids at other angles. Therefore, a dislocation-like movement was observed, proving that Y type dislocations-like exist as well as the displacement of the earth’s crust. The fractured surfaces on top of the gold film helped form a pyramid-like pattern. The movement of the dislocation-like and herringbone patterns was recorded using an optical microscope.