Adjustable and negative thermal expansion from multilayered systems

Abstract

A construct in the form of a multi-layered system built from conventional materials having different mechanical and thermal properties is proposed. This construct can exhibit pre-determined values of thermal expansion which could also be negative. It is shown that for maximising negative thermal expansion (NTE) there should be a combination of thin layers of stiff materials having a high positive coefficient of thermal expansion (CTE) bonded with thicker layers of a soft material having low CTE values and, more importantly, having Poisson's ratio as high as possible.