Origami Metamaterials for Tunable Thermal Expansion

Materials with engineered thermal expansion, capable of achieving targeted area/volume changes in response to variations in temperature, are important for a number of aerospace, optical, energy, and microelectronic applications. While most of the proposed structures with engineered coefficient of thermal expansion consist of bi‐material 2D or 3D lattices, here it is shown that origami metamaterials also provide a platform for the design of systems with a wide range of thermal expansion coefficients. Experiments and simulations are combined to demonstrate that by tuning the geometrical parameters of the origami structure and the arrangement of plates and creases, an extremely broad range of thermal expansion coefficients can be obtained. Differently from all previously reported systems, the proposed structure is tunable in situ and nonporous. Materials with a wide range of thermal‐expansion coefficients are designed using origami principles. Folding of the origami structures enables in situ tunability of the coefficient of thermal expansion, opening avenues for the design of a new class of nonporous systems whose thermal properties can adapt to the surrounding environment.