Stressed triangular lattices on microsized spherical surfaces and their defect management

Abstract

Triangular lattices were assembled on spherical surfaces and caps via thermal stress engineering on core/shell microstructures. The lattices on a complete spherical surface, when the total number is small, contain uniquely fivefold disclinations, whereas scars consisting of pentamer-heptamer chains emerged when more vertices are available (360). Disclination-free pattern were obtained on caps, revealing the defect management strategy in nature. All the experimental observations can be explained by numerical studies to Thomson's problem [J. J. Thomson, Philos. Mag. 7, 237 (1904)]. These results can help understand the various patterns assembled on curved surfaces, and be of essential importance for the en masse fabrication of nanostructures on pliable substrates. © 2008 American Institute of Physics.