Concept
Tunability — where it appears
The ability to change a structure's properties by changing a parameter rather than a material. A folded corrugation's ratio moves across its design space, which is what makes the word apply and what stops it being a material property.
Named by 2 essays across one field — each of them below, with the objects they name alongside it.
A material made of creases
A folded sheet has a Poisson's ratio, a stiffness and a packing behaviour that the flat sheet did not. None of them belong to the paper — they belong to the pattern, and changing the pattern changes them without changing the material at all.
A property you can dial
Steel has one Poisson's ratio. A Miura-folded sheet has a surface of them, and where on that surface it sits is set by the panel shape and by how far it happens to be folded — which is why it is a mechanism rather than a material.
Named alongside it
The objects these essays reach for when they reach for this one.
AuxeticMetamaterialPoisson's ratioDesign spaceGeometric propertyKinematics