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 G129 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 G129 weaving (ideal Σ+ weaving) is formed by keratin fibres in the outermost layer of mammalian skin, probably templated by a folded membrane.