Controllable thermal expansion of large magnitude in chiral negative Poisson's ratio lattices

Abstract

Abstract Lattices of controlled thermal expansion are presented based on planar chiral lattice structure with Poisson's ratio approaching . Thermal expansion values can be arbitrarily large positive or negative. A lattice was fabricated from bimetallic strips and the properties analyzed and studied experimentally. The effective thermal expansion coefficient of the lattice is about K . This is much larger in magnitude than that of constituent metals. Nodes were observed to rotate as temperature was changed corresponding to a Cosserat thermoelastic solid.