Lattice Materials with Reversible Foldability

The authors introduce a new class of lattice materials, where a controlled simultaneous folding of the lattice walls results in a significant size reduction while preserving the overall shape of the original lattice. This reversible folding scheme results in 67 and 50% reduction in size at each level for lattices with triangular and square grid topologies, respectively, while the design enables multiple levels of folding to achieve a desired final size. The authors study the elastic properties and the phononic band structure of the lattice at different stages of folding, using analytical and finite element methods. The proposed concept provides new opportunities for the development of multifunctional deployable structures through significant changes in the size and properties of lattice materials by folding.