Related papers: Isotropic Negative Thermal Expansion Metamaterials
Hyperbolic (or indefinite) materials have attracted significant attention due to their unique capabilities for engineering electromagnetic space and controlling light propagation. A current challenge is to find a hyperbolic material with…
The control of magnetic fields, essential for our science and technology, is currently achieved by magnetic materials with positive permeability, including ferromagnetic, paramagnetic, and diamagnetic types. Here we introduce materials with…
Extrusion 3D-printing of biopolymers and natural fiber-based biocomposites allows for the fabrication of complex structures, ranging from gels for healthcare applications to eco-friendly structural materials. However, traditional polymer…
The concept of superscattering is extended to the thermal field through the design of a thermal superscatterer based on transformation thermodynamics. A small thermal scatterer of arbitrary shape and conductivity is encapsulated with an…
We demonstrate thin-film metamaterials with resonances in the mid-infrared wavelength range. Our structures are numerically modeled and experimentally characterized by reflection and angularly-resolved thermal emission spectroscopy. We…
A definition of the Gr\"uneisen parameters for anisotropic materials is derived based on the response of phonon frequencies to uniaxial stress perturbations. This Gr\"uneisen model relates the thermal expansion in a given direction…
The thermal expansion of polycrystalline MgB2 from 5-300 K is studied using high-resolution capacitance dilatometry. The thermal expansivity exhibits a small jump of -5.8x10-8 K-1 at Tc (in accord with expectations from the Ehrenfest…
Thermoelectric (TE) generators can directly convert heat into electricity, but their performance is often constrained by limited temperature gradients. Here it is shown that width-modulated metamaterials with constrictions and expansions…
Metamaterials are composite structures whose properties arise from a mesoscale organization of their constituents. Provided this organization occurs on scales smaller than the characteristic lengths associated with their response, it is…
The thermal management have been widely focused due to broad applications. Generally, the deformation can largely tune the thermal transport. The main challenge of flexible electronics/ materials is to maintain thermal conductance under…
Compacted unsaturated swelling clay is often considered as a possible buffer material for deep nuclear waste disposal. An isotropic cell permitting simultaneous control of suction, temperature and pressure was used to study the…
Magnetic materials are crucial in nonreciprocal electromagnetic devices, such as isolators, circulators, and nonreciprocal phase shifters. However, their use is often limited by the need for a uniform bias magnetic field and nonuniform…
Many materials have anisotropic thermal conductivity, with diverse applications such as transistors, thermoelectrics, and laser gain media. Yet measuring the thermal conductivity tensor of such materials remains a challenge, particularly…
We report on highly tunable radio frequency (rf) characteristics of a low-loss and compact three dimensional (3D) metamaterial made of superconducting thin film spiral resonators. The rf transmission spectrum of a single element of the…
The thermal conductivity of Functionally Graded Materials (FGMs) can be efficiently designed through topology optimization to obtain thermal meta-structures that actively steer the heat flow. Compared to conventional analytical design…
A metamaterial with frequency dependent double negative effective properties is constructed from a sub-wavelength periodic array of coated rods. Explicit power series are developed for the dispersion relation and associated Bloch wave…
A robust wedge setup is proposed to unambiguously demonstrate negative refraction for negative index metamaterials. We applied our setup to several optical metamaterials from the literature and distinctly observed the phenomena of negative…
We use first-principles theory to show that the ingredients assumed to be essential to the occurrence of negative thermal expansion (NTE) -- rigid unit phonon modes with negative Gr\"{u}neisen parameters -- are neither sufficient nor…
We present experimental and theoretical results on an acoustic metamaterial that exhibits negative effective modulus in a frequency range from 0 to 450 Hz. One-dimensional acoustic metamaterial with an array of side holes on a tube was…
The rapidly increasing number of 2-dimensional (2D) materials that have been isolated or synthesized provides an enormous opportunity to realize new device functionalities. Whereas their optical and electrical characterization have been…