Illusion Thermotics

Abstract

"Fata Morgana" or "Mirage" phenomena have long been captivated as optical illusions, which actually relies on gradient-density air or vapor. Man-made optical illusions have witnessed significant progress by resorting to artificially structured metamaterials. Nevertheless, two long-standing challenges remain formidable: first, exotic parameters (negative or less than unity) become inevitable; second, the signature of original object is altered to that of a virtual counterpart. It is thus not able to address the holy grail of illusion per se, since a single virtual object still exposes the location. In this study, those problems are successfully addressed in a particular setup-illusion thermotics, which identically mimics the exterior thermal behavior of an equivalent reference and splits the interior original heat source into many virtual signatures. A general paradigm to design thermal illusion metadevices is proposed to manipulate thermal conduction, and empower robust simultaneous functions of moving, shaping, rotating, and splitting heat sources of arbitrary cross sections. The temperature profile inside the thermal metadevice can mislead the awareness of the real location, shape, size, and number of the actual heat sources. The present concept may trigger unprecedented development in other physical fields to realize multiple functionalized illusions in optics, electromagnetics, etc.

A Multilayer Film Based Selective Thermal Emitter for Infrared Stealth Technology

“…Materials with radiation wavelength selectivity have received considerable attention from researchers due to their potential applications, especially in thermophotovoltaic (TPV) systems, radiative cooling, infrared stealth, etc. A TPV system is an electrical generator that converts heat radiation energy into electrical energy with high efficiency.…”

“…Contrary to radiative coolers, infrared stealth technology, which is widely utilized by aircrafts, tanks, ships, missiles, and satellites to make them “invisible” to infrared detection equipment, demands the suppression of thermal radiation energy in the two atmospheric windows (3–5 and 8–14 µm) representing the main transmission channels for electromagnetic waves in the atmosphere . The thermal radiation energy, defined as the radiance exitance P , radiated from an object can be suppressed by both reduction of the emissivity and the real temperature, according to the Steven–Boltzmann Law, P = εσT 4 , where σ is the Steven–Boltzmann constant and ε and T are the emissivity and absolute temperature of the object, respectively.…”

Organic‐Inorganic Hybrid Perovskite Single Crystals: Crystallization, Molecular Structures, and Bandgap Engineering

“…[19][20][21][22] Especially in the area of solar cell, with the rapid developments of the discovery of new perovskite system and the optimization of device fabrication, the power conversion efficiencies of these perovskites solar cells (typically lead halide based) have been increased from 3% to~23% in the past 10 years. [3][4][23][24][25][26][27][28][29][30] Compared with other forms of materials, single crystals allow investigation of intrinsic properties [31][32][33][34] like charge transport, anisotropy, ultrafast spectrum. Because single crystals have nearly perfect structures and minimum concentration of structure imperfections (i. e., grain boundaries) and impurities, which decrease the charge trapping and scattering and improve the intrinsic properties.…”

Full‐Parameter Omnidirectional Thermal Metadevices of Anisotropic Geometry

“…In addition, the proposed schemes are implemented with existing natural bulk materials, thus indicating that our advanced scheme is ready for real engineering applications. Our approach may provide a more general platform for thermal camouflage, multiphysics cloak, multiphysics cloaking sensor, and thermal diodes …”