A stiff thin film on a heated compliant substrate may buckle when the system is cooled due to the thermal expansion mismatch between the film and substrate. Highly ordered and disordered herringbone patterns (wavy structures) then emerge as the system continues to cool. We have established an analytic approach to study one-dimensional, checkerboard, and ordered herringbone buckling patterns. The analytical approach gives the buckle wave length and amplitude in terms of the thin film and substrate elastic properties, thin film thickness, and the thermal strain. It is shown that the herringbone mode has the lowest energy, which explains why this mode is frequently observed in experiments. These classes of materials might be interesting as a route to high performance electronics with full, two-dimensional stretchability.
ASJC Scopus subject areas
- Physics and Astronomy(all)