Appl. Phys. Lett. 90, 133119 (2007)
Mechanics of Precisely Controlled Thin Film Buckling on Elastomeric Substrate
Hanqing Jiang, YUgang Sun, John A. Rogers, Young Huang

Stretchable electronics has many important and emerging applications. we (Nature Nanotechnology, 1, 201-207, 2006) recently demonstrated stretchable electronics based on precisely controlled buckle geometries in GaAs and Si nanoribbons on elastomeric substrates. A nonlinear buckling model is presented in this paper to study the mechanics of this type of thin film/substrate system. An analytical solution is obtained for the buckling geometry (wavelength and amplitude) and the maximum strain in buckled thin film. This solution agrees very well with the experiments, and shows explicitly how buckling can significantly reduce the thin film strain to achieve the system stretchability.

The precisely controlled thin film buckling is achieved by chemically patterning the substrate (e.g., PDMS) with periodic strong bonding (Wact) and weak bonding (Win). For example, a 0.3 um thin GaAs film buckled on a patterned PDMS substrate with Wact = 10 um, Win = 400 um, and prestrain = 60% , the maximum strain is only 0.6%, two orders of magnitude smaller than the 60% prestrain.