Controllable wrinkle configurations by soft micro-patterns to enhance the stretchability of Si ribbons

Wrinkle configurations can provide brittle Si ribbons with excellent stretchability via mechanical buckling. We propose a strategy using micro-patterns to control the wrinkle configurations in 'pop-up' and 'pop-down' styles, as well as the wrinkle's wavelength. After the wrinkle configuration is stretched flat, the micro-patterns will deform to buffer the Si ribbons, which enhances the additional stretchability of such structures. The experimental results show that the micro-patterns determine the wrinkle configurations of Si ribbons and their stretchability can reach 51.2%. The analytical modeling and FEM simulation reveal the mechanism of such a phenomenon.