Journal of the Korean Physical Society, Vol. 75, No. 12, December 2019, pp. 1028∼1032 Distance Effect of Heat Flux Based on Thermal Metamaterials Taekyung Lim, Sang-Mi Jeong and Sanghyun Ju Department of Physics, Kyonggi University, Suwon 16227, Korea Keun-Hyeok Yang Department of Architectural Engineering, Kyonggi University, Suwon 16227, Korea Ok Sung Jeon and Sang Yoon Park ∗ Advanced Institutes of Convergence Technology, Seoul National University, Suwon 16229, Korea Young Joon Yoo † Invisible, Business Incubation Center, Kyonggi University, Suwon 16227, Korea (Received 31 October 2019; revised 12 November 2019; accepted 12 November 2019) In this paper, we studied the heat flux effect of thermal metamaterials according to the distance of each layer, which can effectively suppress heat propagation and improve an adiabatic property, through the three-dimensional finite-difference time-domain simulation. Based on multiple layers of thermal meta-materials, the heat flux in the propagation direction could be suppressed by thermal meta-layers. The heat flux transferred through the gap between thermal meta-layers could also be efficiently suppressed by controlling the gap of each meta-layer in a concrete block. It was found that the heat transfer characteristics and the thermal insulation efficiency can be adjusted according to the change of the distance in the 5-layers meta-structure. Furthermore, the adiabatic property greatly changed depending on the location of the heat source and the thermal meta- structure transferred into the concrete. The appropriate thickness of each meta-layer should be used to suppress heat transfer and improve adiabatic properties in the concrete structure from the results of the 10-layer meta-structure. PACS numbers: 78.67.Pt, 44.35.+c, 44.05.+e, 66.10.Cb Keywords: Metamaterial, Thermal, Heat flux, Adiabatic property DOI: 10.3938/jkps.75.1028 I. INTRODUCTION Metamaterials do not exist in natural systems, which are artificial materials providing unobservable character- istics by an engineer. The electromagnetic (EM) meta- material consists of a periodic array of meta-atoms de- signed as metal or dielectric material with a size much smaller than the wavelength of the incident light. The metamaterials are designed to interact with light and sound in ways that can be applied to new applications as a transparent cloak, superlens, absorber, array patch an- tennas, and sensitive sensors [1–7]. Recently, the meta- material applications area has rapidly expanded to ap- plications such as EM wave hyper-transmitter, 5G com- munication, acoustic cloaking/absorbers, and thermal clocking [8–13]. Since the expansion of thermal MMs, many researchers ∗ E-mail: yoonpark77@snu.ac.kr † E-mail: yjyoo1979@gmail.com have studies on heat control. The heat control using metamaterials has been increasing recently [14–19], and studies have been conducted to determine applications of thermal meta-materials to thermoelectrics, thermal cloaks, thermal logic gates, and thermal diodes [20–24]. Especially, the blocking technologies of heat propagation in the inner circuits are critical to the stable operation of electronic nanoscale devices. Thermal blocking metama- terials can suppress the breakdown of electronic circuits by preventing the heat flux inner electronic circuits. In addition, the walls of buildings with metamaterials can effectively suppress heat transfer, the adiabatic proper- ties of those significantly increased. Moreover, in the wall of the building, the periodic arrangement of thermal insulation meta-layers can improve the adiabatic proper- ties [25]. In this research, we investigated the heat flux effect for thermal blocking by the control of distance of the insulation meta-layers, which is composed of a plate- shaped meta-layers structure embedded in the concrete pISSN:0374-4884/eISSN:1976-8524 -1028- c 2019 The Korean Physical Society