Heat Flux Manipulation with Engineered Thermal Materials

Abstract

Utilizing a multilayered composite approach, we have designed and constructed a new class of artificial materials for thermal conduction. We show that an engineered material can be utilized to control the diffusive heat flow in ways inconceivable with naturally occurring materials. By shielding, concentrating, and inverting heat current, we experimentally demonstrate the unique potential and the utility of guiding heat flux.

Manipulating DC Currents with Bilayer Bulk Natural Materials

“…Besides making objects invisible [1][2][3][4] , many other novel devices are rapidly emerging, with a representative one being a concentrator [5,6] that can enhance the energy density of incident waves in a given area. In addition to manipulation of EM waves [1][2][3][4][5][6] , the theoretical tool of coordinate transformation has been extended to other areas of physics (such as acoustic waves [7] , matter waves [8] and elastic waves [9] ).Recently, many significant achievements have been made in the manipulation of magnetostatic field [10][11][12][13][14][15] , thermal conduction [16][17][18][19] , and electrostatic field [20][21][22][23][24] . In 2007, Wood and Pendry proposed a dc metamaterial that pointed the way towards the design of static magnetic cloak [10] , and the dc metamaterial was experimentally verified soon afterwards [11] .…”

“…On the basis of form invariance of the heat conduction equation, transformation thermodynamics is investigated to manipulate diffusive heat flow [16] ; through tailoring inhomogeneity and anisotropy of conductivities, transient thermal cloaking has been experimentally demonstrated [17] . In addition, manipulation of heat flux with only two kinds of materials (by utilizing a multilayered composite approach) has been reported [18,19] . Recently, a transformation-optics based dc electric cloak, composed of inhomogeneous and anisotropic conductivities, has been implemented using anisotropic and spatially-varying network of resistors [20] .…”

“…Recently, many significant achievements have been made in the manipulation of magnetostatic field [10][11][12][13][14][15] , thermal conduction [16][17][18][19] , and electrostatic field [20][21][22][23][24] . In 2007, Wood and Pendry proposed a dc metamaterial that pointed the way towards the design of static magnetic cloak [10] , and the dc metamaterial was experimentally verified soon afterwards [11] .…”

“…Also, the proposed schemes, derived directly from the electric conduction equation, are exact rather than approximate ones. Finally, excellent performance can be achieved by employing only natural bulk materials, thus indicating that our advanced scheme may be readily extended for various applications beyond dc control [7,13,14,18,27,28] . show the simulated results of the object with only a single layer of air and copper, respectively; significant distortions can be clearly observed.…”

Collection of low-grade waste heat for enhanced energy harvesting

“…7,8 Heat flux focusing is one manner in which heat flow may be controlled, [2][3][4][5]9,10 and different effects, such as heat flux cloaking or reversal, have also been demonstrated theoretically 9,11 and experimentally for thick devices, 10 planar structures, 12,13 and three-dimensional objects. 14 Recently, thermoelectric devices have also been applied to facilitate the manipulation of heat flow for an active thermal cloak around arbitrarily shaped regions.…”