BUCKLING ANALYSIS OF ELASTIC FILM BONDED ON SMP SUBSTRATE¹⁾

The shape memory polymer (SMP) can restore its shape under certain conditions after its shape deformation. Therefore, as a soft substrate material, it is widely used in flexible electronic devices. For a two-layer structure made of the shape memory polymer (SMP) substrate and the elastic thin film, the elastic film on the surface can form wrinkling patterns when the SMP substrate contracts. Due to the shape memory characteristics of the SMP, the shape of the flexible electronic device is related to the time and the temperature. In this paper, the wavelength and the amplitude of the wrinkling patterns are analyzed, and the mechanical properties of the SMP at different temperatures are measured by experiments. With one-dimensional strain recovery function of the SMP and the buckling characteristics of the elastic film bonded to a soft substrate, the variations of the wave length and the amplitude of the wrinkling patterns against the time and the temperature are obtained, with good agreement with the experimental results.