Thermal cloak-concentrator

Shen, Xiangying; Li, Ying; Jiang, Chaoran; Ni, Yushan; Huang, Jiping

doi:10.1063/1.4959251

Cited by 127 publications

(92 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The heat transfer process for such thermal harvesting devices [11][12][13][14][15][16][17][18][19][20][21][22][23] can be presented by the rigorous theoretical model 8,9,16,24 as shown in Fig. 1.…”

Section: Geometrical Profile and Theoretical Analysismentioning

confidence: 99%

“…κ 0 is the thermal conductivity of the surrounding. The profile of a thermal harvesting device [14][15][16][17][18][19][20][21][22][23][24][25] based on a spatial transformation can be separated into three parts including the background (Part I), concentrating region (Part II), and central region (Part III). In this view, heat transfer properties in the entire system can be deduced by rigorously solving the conduction function of the three parts under certain boundary conditions.…”

Section: Geometrical Profile and Theoretical Analysismentioning

confidence: 99%

“…The form invariance of the heat diffusion equation after coordinate transformation led to the extension of TO to the thermal field to guide the design and experiments of thermal TO devices including thermal cloaks, [7][8][9][10][11][12][13] concentrators, [14][15][16][17][18][19][20][21][22][23][24][25] rotators, 26 camouflage, 27 and diodes. 28 With thermal TO devices, an active and efficient control of thermal energy can be achieved with a pre-designed profile and reasonable arrangement of metamaterials.…”

Section: Introductionmentioning

confidence: 99%

“…To realize local heat harvesting, alternative composite materials with a wedge-like structure (e.g., spoke, fan, and sensu) were widely adopted in previous studies. [14][15][16][17][18][19][21][22][23] The feasible method for fabricating a thermal concentrator is reversing the conductivity components 15 in the transformational domain, i.e., keeping the radial component considerably larger than the azimuthal component. Based on this concept, theoretical 3D thermal harvesting cells 16 have been demonstrated by employing naturally available materials with tunable anisotropy.…”

Section: Introductionmentioning

confidence: 99%

“…Furthermore, a type of dual-function thermal metamaterial was proposed by employing homogeneous isotropic materials and shape-memory alloys for realizing automatic switching between a thermal cloak and concentrator. 19 In recent years, TO-based thermal harvesting devices were extended to attain convergent heat transfer 33 via rotation and compression transformations, to design multifunctional metamaterials, [20][21][22][23] which manipulated Laplace fields (thermal and electric) 22 simultaneously, and to fabricate tunable unit-cell thermal shifters 34 by considering the heat flux bending 35,36 in the material layers. To concentrate the heat flux more effectively, the influence of conductivities 24 was investigated, and it showed that a larger conductivity ratio of the radial and azimuthal components ensured a better harvesting performance.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Geometrical effects on the concentrated behavior of heat flux in metamaterials thermal harvesting devices

Zhang

Xie

et al. 2017

AIP Advances

View full text Add to dashboard Cite

Thermal harvesting devices based on transformation optics, which can manipulate the heat flux concentration significantly through rational arrangements of the conductivities, have attracted considerable interest owing to several great potential applications of the technique for high-efficiency thermal conversion and collection. However, quantitative studies on the geometrical effects, particularly wedge angles, on the harvesting behaviors are rare. In this paper, we adopt wedge structure-based thermal harvesting schemes, and focus on the effects of the geometrical parameters including the radii ratios and wedge angles on the harvesting performance. The temperature deformations at the boundaries of the compressional region and temperature gradients for the different schemes with varying design parameters are investigated. Moreover, a concept for temperature stabilization was derived to evaluate the fluctuation in the energy distributions. In addition, the effects of interface thermal resistances have been investigated. Considering the changes in the radii ratios and wedge angles, we proposed a modification of the harvesting efficiency to quantitatively assess the concentration performance, which was verified through random tests and previously fabricated devices. In general, this study indicates that a smaller radii ratio contributes to a better harvesting behavior, but causes larger perturbations in the thermal profiles owing to a larger heat loss. We also find that a smaller wedge angle is beneficial to ensuring a higher concentration efficiency with less energy perturbations. These findings can be used to guide the improvement of a thermal concentrator with a high efficiency in reference to its potential applications as novel heat storage, thermal sensors, solar cells, and thermoelectric devices.

show abstract

Section: Geometrical Profile and Theoretical Analysismentioning

confidence: 99%

Section: Geometrical Profile and Theoretical Analysismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Geometrical effects on the concentrated behavior of heat flux in metamaterials thermal harvesting devices

Zhang

Xie

et al. 2017

AIP Advances

View full text Add to dashboard Cite

show abstract

A Brief Review on Thermal Metamaterials for Cloaking and Heat Flux Manipulation

2019

View full text Add to dashboard Cite

Progress in material science has allowed the control of different physical fields in a manner that would be unachievable with ordinary materials. The development of engineered materials (the so‐called metamaterials) to control the conductive heat flux has revolutionized the manner of manipulating thermal energy and allowed the possibility of guiding the heat flux in ways difficult to accept for human intuition. Herein, a brief review regarding the recent progress and developments in thermal metamaterials conceived to perform several conductive heat flux manipulation tasks is provided. Deeply theoretical discussions concerning design methodologies are left a side, and the focus is made on the design and manufacturing feasibility of metamaterials for thermal cloaking and camouflage, heat flux concentration, and inversion, among other applications that lead to the next generation of thermal devices.

show abstract

Path‐Dependent Thermal Metadevice beyond Janus Functionalities

Liu

Yang

et al. 2020

Advanced Materials

Self Cite

View full text Add to dashboard Cite

Many intriguing electromagnetic (EM) effects have been realized by these materials and devices. For example, the Janus monolayer of transition metal dichalcogenides with inherent structural asymmetry enables the bandgap tenability and distinctive optical properties in two opposite directions. [6] Meanwhile, Janus metasurfaces realize switchable optical functions on the incident visible light from different angles. [7,8] All these kinds of effects are accomplished by employing intrinsic asymmetry or orientations of the constituent materials or meta-atoms, which interplay with the directionality of the electromagnetic waves. Considering their broad applicability and great potential in photonics, it is desirable to extend the concept of Janus metadevice to other fields, such as heat transfer. Using those thermal metadevices, it would be possible to shield heat flux [9] from one direction, while at the same time accumulating from another. To date, various thermal metadevices [10,11] with individual functionalities such as thermal cloaking, [12-24] concentrating, [25,26] or transparency [27,28] have already been demonstrated thanks to the development of transformation thermotics inspired by the transformation Janus metamaterials, metasurfaces, and monolayers have received intensive attention in nanophotonics and 2D materials. Their core concept is to introduce asymmetry along the wave propagation direction, by stacking different materials or layers of meta-atoms, or breaking out-of-plane mirror asymmetry with external biases. Nevertheless, it has been hitherto elusive to realize a diffusive Janus metadevice, since scalar diffusion systems such as heat conduction normally operate in the absence of polarization control, spin manipulation, or electric-field stimuli, which all are widely used in achieving optical Janus devices. It is even more challenging, if not impossible, for a single diffusive metadevice to exhibit more than two thermal functions. Here a path-dependent thermal metadevice beyond Janus characteristics is proposed, which can exhibit three distinct thermal behaviors (cloaking, concentrating, and transparency) under different directions of heat flow. The rotation transformation mechanism of thermal conductivity provides a robust platform to assign a specific thermal behavior in any direction. The proof-of-concept experiment of anisotropic in-plane conduction successfully validates such a path-dependent trifunction thermal metamaterial device. It is anticipated that this path-dependent strategy can provide a new dimension for multifunctional metamaterial devices in the thermal field, as well as for a more general diffusion process. Inspired by the two-faced god in Roman mythology, Janus metamaterials or metadevices refer to artificial devices that integrate two direction-dependent functionalities in a single

show abstract

Thermal cloak-concentrator

Cited by 127 publications

References 39 publications

Geometrical effects on the concentrated behavior of heat flux in metamaterials thermal harvesting devices

Geometrical effects on the concentrated behavior of heat flux in metamaterials thermal harvesting devices

A Brief Review on Thermal Metamaterials for Cloaking and Heat Flux Manipulation

Path‐Dependent Thermal Metadevice beyond Janus Functionalities

Contact Info

Product

Resources

About