ABSTRACT
In recent years, the exotic capability of metamaterials to absorb perfectly electromagnetic wave has induced potentially many practical purposes, especially, the rapid growth of 5G/6G telecommunication systems. Therefore, the perfect metamaterial absorbers have been reduced in a fast way to several hundred times smaller than the working wavelength. However, it is still a big obstacle to obtain the real low-frequency perfect absorbers (LFPAs), since the absorption frequency and the physical size are two conflicting requirements. To overcome this limitation, we review rather briefly the existing optimization strategies for LFPAs, by which the merits of geometrical optimization and the hybridization with parasitic elements will be highlighted. In addition, to be more feasible in electronic devices, the studies on flexible LFPA are also mentioned. Especially, we focus on recent investigations, which use inkjet-printing as an advanced fabrication technique to create the cost-efficient, printable and flexible LFPA.
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Do Thuy Chi
Do Thuy Chi received Ph. D. from Institute of Physics, Vietnam Academy of Science and Technology (VAST) in 2013. Her research interests are photonics and metamaterials (MMs).
Bui Xuan Khuyen
Bui Xuan Khuyen obtained Ph. D. from Hanyang University, Korea in 2018. His research comprises MMs, especially, low-frequency MMs.
Bui Son Tung
Bui Son Tung received Ph. D. from Hanyang University, Korea in 2018. He has studied MMs and electromagnetically-induced transparency.
Vu Dinh Lam
Vu Dinh Lam obtained Ph. D. from Institute of Materials Science (IMS), VAST. He is a Professor of IMS, VAST and Rector of Graduate University of Science and Technology, VAST. His research includes MMs, nanostructures, multiferroics and solar cells.
Liang Yao Chen
Liang Yao Chen received Ph. D. from Iowa State University, USA in 1987. He is a Chang Jiang Professor at Fudan University, China. His research interests are optical properties of solids, including MMs, metals, semiconductors and thin films by using many types of optical methods and instruments. He has published over 300 SCI papers in the relevant fields.
YoungPak Lee
YoungPak Lee obtained Ph. D. in 1987 from Iowa State University, USA. He has been a Distinguished Professor, Hanyang University, Korea, and is a Distinguished Professor of Fudan University, China. He is a former President of the Korean Physical Society, and a Fellow of the Korea Academy of Science and Technology. He has published over 700 SCI papers with an h-index of 62 as of Sep, 2020. His current investigations comprise MMs and spin-photonic crystals.