Multi-stable cylindrical lattices

We present a cylindrical lattice structure that mimics the behaviour of the virus bacteriophage T4 in having two (or more) stable states which differ in their radii and length. While the virus achieves bistability through molecular mechanisms we use composite materials to exploit the interplay between pre-stress, material properties and structural geometry. We demonstrate (computationally) that multi-stability is a robust phenomenon. We also show (analytically) that it is possible to choose the design variables so that the energy is independent of the radius, thus resulting in every state of the structure being stable.