157nm_w=11.1mm_130dpi_28
Pictured is a thin polymer film floating on a bath of water and draped over a metal sphere, giving rise to radial wrinkles. The sheet is 157 nm thick and 22.2 mm wide.

“Curvature-induced stiffness and the spatial variation of wavelength in wrinkled sheets” appeared in PNAS (link). This work proposes and experimentally tests a basic framework for predicting wrinkle wavelengths in curved and/or non-uniform topographies. Wrinkle patterns are ubiquitous in nature and technology, occurring in biological tissues, textiles, and polymer films. Observing the wavelength of these patterns offers a non-invasive way to measure film properties or the mechanical environment.

Curvature-induced stiffness and the spatial variation of wavelength in wrinkled sheets. J. D. Paulsen, E. Hohlfeld, H. King, J. Huang, Z. Qiu, T. P. Russell, N. Menon, D. Vella, and B. Davidovitch. Proceedings of the National Academy of Sciences, USA (2016).  pdf  link  bibtex

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