Cooperative buckling of parallel nanowires on elastomeric substrates

The cooperative buckling behaviors of parallel nanowires on an elastomeric substrate are investigated based on a finite element framework. Under compression of the elastomeric substrate, an especial helical buckling mode of nanowires and buckling evolution with effective compressive strain are observed. It is revealed that typical buckling characteristics of two parallel nanowires strongly depend on the distance between them. When the distance is smaller than a critical value h_S/2 (half of a representative buckling spacing of a single nanowire on an elastomeric substrate), with decreasing of the separation distance, the buckling spacing, displacement amplitudes and the ratio between the in-/out-of-plane amplitudes all increase significantly. For parallel nanowire assembles, when the nanowires are closely arrayed, the buckling spacing notably increases with the number of nanowires. This study contributes to controllable buckling of stiff elements on a soft substrate and may shed some light on the design and optimization of flexible electronics.