Post Buckling Analysis of Thin Membrane for the Flexible Electronics

This paper presents the experiment work and numerical solution to investigate wrinkle formation and evolution in thin membranes at elevated temperatures. The specimens consist of Kapton circular membranes supported on steel substrate. The membranes were heated from room temperature to 100°C. The DIC (digital image correlation) was used to monitor the profiles of membranes at discrete temperatures. The nonlinear post buckling analysis was used for numerical study of membrane wrinkling. The nonlinear post buckling solution shows that the global buckling of membrane significantly reduces bending stiffness thus to create localized buckling modes accounting for the wrinkle generation. The wrinkle evolution is stable until the temperature reaches the next critical value. After this critical temperature, the wrinkle evolution is accelerated until the final temperature. The finite element simulation results are consistent with experimental observations.