From three-dimensional weavings to swollen corneocytes.

A novel technique to generate three-dimensional Euclidean weavings, composed of close-packed, periodic arrays of one-dimensional fibres, is described. Some of these weavings are shown to dilate by simple shape changes of the constituent fibres (such as fibre straightening). The free volume within a chiral cubic example of a dilatant weaving, the ideal conformation of the G(129) weaving related to the Σ(+) rod packing, expands more than fivefold on filament straightening. This remarkable three-dimensional weaving, therefore, allows an unprecedented variation of packing density without loss of structural rigidity and is an attractive design target for materials. We propose that the G(129) weaving (ideal Σ(+) weaving) is formed by keratin fibres in the outermost layer of mammalian skin, probably templated by a folded membrane.