Buckling instabilities in periodic composite polymeric materials†

Although buckling instabilities in elastic solids have been known for a long time, high interest in this phenomenon is relatively recent. The current and prospective applications in flexible electronics, materials with tunable surface properties (adhesion and wettability), responsive photonic and phononic structures, and reinforced nanocomposites led to a surge in the interest in buckling instabilities. In fact, some of the applications, such as flexible electronics and metrology, have advanced at a tremendous pace only within the past few years. In this review, we discuss some of the most recent progress in the fundamental understanding of buckling instabilities in periodic multi-component polymer materials and porous polymer structures. We also discuss how the buckling can be localized to predetermined regions and hence form periodic instability patterns. Finally, we present several recent examples where buckling instabilities have been employed as a patterning tool to realize complex surface arrays of various materials.