Lightweight Mechanical Metamaterials with Tunable Negative Thermal Expansion

Abstract

Ice floating on water is a great manifestation of negative thermal expansion (NTE) in nature. The limited examples of natural materials possessing NTE have stimulated research on engineered structures. Previous studies on NTE structures were mostly focused on theoretical design with limited experimental demonstration in two-dimensional planar geometries. In this work, aided with multimaterial projection microstereolithography, we experimentally fabricate lightweight multimaterial lattices that exhibit significant negative thermal expansion in three directions and over a temperature range of 170 degrees. Such NTE is induced by the structural interaction of material components with distinct thermal expansion coefficients. The NTE can be tuned over a large range by varying the thermal expansion coefficient difference between constituent beams and geometrical arrangements. Our experimental results match qualitatively with a simple scaling law and quantitatively with computational models.

Progress of Research in Negative Thermal Expansion Materials: Paradigm Shift in the Control of Thermal Expansion

“…Control of thermal expansion using specific characteristics of materials, particularly in a negative α region, are highly limited in an operating temperature and/or a magnitude of α because of the severe constraints of available materials. To overcome these difficulties, designated structures consisting of two materials having different (positive) thermal expansions and voids are proposed as an artificial materials showing NTE (Takezawa et al, 2015; Wang et al, 2016). The present result is expected to stimulate those activities as a “natural” counterpart of the artificial structures.…”

Elastic properties of superconductors and materials with weakly correlated spins

“…They further include magnetocaloric, elastocaloric, and barocaloric phenomena with modern cooling applications, and encompass new frontiers in the design of artificial materials 8–18 . Recently, microarchitectures with effective negative thermal expansion have been designed through structural integration of constituents with dissimilar but positive thermal expansion coefficients 19 . Combining the reported advances in microarchitecture with thermal properties of materials such as Invar and anti-Invar alloys may broaden the spectrum of applications 20 .…”

Origami Metamaterials for Tunable Thermal Expansion

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materials, which include 2D [6][7][8][9][10] and 3D [11][12][13][14][15] multimaterials lattices as well as bi-materials microstructures, [16,17] are all porous and characterized by a response that is very difficult to be tuned after manufacturing.Origami-the ancient art of paper folding-not only leads to aesthetically pleasant structures but also enables the design of materials with novel mechanical properties, including negative and adjustable Poisson's ratio, [18][19][20][21] programmable curvature [22] and mechanical response, [23] and multistability. [24] Here, we focus on a simple origami tessellation, the Miuraori, [25] and combine experiments with simulations to demonstrate that this system can also provide a platform for the design of materials with a wide range of coefficients of thermal expansion.

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“…materials, which include 2D [6][7][8][9][10] and 3D [11][12][13][14][15] multimaterials lattices as well as bi-materials microstructures, [16,17] are all porous and characterized by a response that is very difficult to be tuned after manufacturing.…”