Mathematicians declare a new class of shape

Not like your typical circle or square, the flexible 'soft cell' is seen throughout nature

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Mathematicians have declared a new class of shape: the 'soft cell', which can take different forms so long as it has rounded edges and fits together in a tessellated grid-known as 'tiling' in maths.

Tessellating fully rounded shapes isn't possible in 2D, unless there are 'cusps' the sharp points between curves (like the top of a teardrop).

An example of this in 2D is the crosssection of an onion.