Buckling configurations of stiff thin films tuned by micro-patterns on soft substrate

Wrinkling and buckling of stiff film/soft substrate system has great potential applications in many areas, especially in stretchable electronics. Inspired by the micro-patterns to tune the interfacial adhesion strength, a novel way to tune three buckling configurations (i.e., wrinkling, upward and downward buckling) by using the micro-patterns on the soft substrate was found experimentally. The established governing equations to distinguish the three buckling configurations are consistent with the experimental observations. Results show that the geometries of the micro-patterns, the material properties and the interfacial adhesion between the stiff film and the micro-patterned soft substrate can tremendously influence the final buckling configurations. The proposed analytical governing equations can not only clarify the mechanism of the micro-patterns on the tuning of different buckling configurations, but also be used to design the buckling configurations as desired. (C) 2018 Elsevier Ltd. All rights reserved.