Nature inspires new methods of making porous materials

The phenomenon of porosity gradation — where materials show variations in their underlying structural cavities — is found throughout nature in tree trunks, bones and beehives among other structures.

It allows for maximum strength-to-weight ratio and the efficient transferring of forces in order to minimise stresses and avoid whole structure failure.

For instance, a crack in the branch of a tree will not lead to the felling of the tree in the same way that a broken ankle will not lead to collapse of the whole leg.

Dr Carmen Torres-Sanchez of the Department of Mechanical Engineering at Heriot-Watt University, seeks to study these instances of porosity gradation in nature in order to develop better artificial materials.

‘We mechanical engineers are obsessed with how solid, homogenous materials behave, using concepts such as Young’s modulus and bulk modulus — but when you look at nature, there’s nothing that is really homogenous out there,’ Torres-Sanchez told The Engineer.