Elastocapillary coalescence in wet hair


We investigated why wet hair clumps into bundles by dunking a model brush of parallel elastic lamellae into a perfectly wetting liquid. As the brush is withdrawn, pairs of bundles aggregate successively, forming complex hierarchical patterns that depend on a balance between capillary forces and the elasticity of the lamellae. This capillary-driven self-assembly of flexible structures, which occurs in the tarsi of insects1 and in biomimetic adhesives2 but which can also damage micro-electromechanical structures3,4,5,6 or carbon nanotube ‘carpets’6,7,8, represents a new type of coalescence process.

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Figure 1: Flexible lamellae stick together after wetting.


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Correspondence to José Bico.

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Bico, J., Roman, B., Moulin, L. et al. Elastocapillary coalescence in wet hair. Nature 432, 690 (2004).

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