Vigorous development of 5G communication technologies can boost mobile networks yet bring in electromagnetic interferences and safety concerns in utilizing electronic devices. Particularly, 5G network can not only involve a low‐frequency band of n78 (3.3–3.8 GHz) but also cover multi‐frequency bands of n77 (3.3–4.2 GHz) and n79 (4.4–5.0 GHz), displaying multiple electromagnetic radiations. Countless efforts have been devoted to investigating electromagnetic wave (EMW) absorbers with low‐ and multi‐band absorption properties. However, in terms of emerging materials and designs, few reports propose the mechanisms related to those properties. This perspective briefly reviews the impressive achievements of low‐ and multi‐frequency EMW absorbers and analyzes the design strategies that may enable low‐ and multi‐frequency absorption. Furthermore, the cutting‐edge mechanisms of corresponding electromagnetic responses, such as Snoek limit, quarter wavelength, and dielectric‐magnetic synergy effects are elaborated. Thus, this perspective can shed light on the new trends and ongoing challenges for EMW absorbers and further promote their practical application.

Emerging Materials and Designs for Low‐ and Multi‐Band Electromagnetic Wave Absorbers: The Search for Dielectric and Magnetic Synergy?

Initiating VB-Group Laminated NbS2 Electromagnetic Wave Absorber toward Superior Absorption Bandwidth as Large as 6.48 GHz through Phase Engineering Modulation

High-performance microwave absorption enabled by Co3O4 modified VB-group laminated VS2 with frequency modulation from S-band to Ku-band

With rapid development of 5G communication technologies, electromagnetic interference (EMI) shielding for electronic devices has become an urgent demand in recent years, where the development of corresponding EMI shielding materials against detrimental electromagnetic radiation plays an essential role. Meanwhile, the EMI shielding materials with high flexibility and functional integrity are highly demanded for emerging shielding applications. Hitherto, a variety of flexible EMI shielding materials with lightweight and multifunctionalities have been developed. In this review, we not only introduce the recent development of flexible EMI shielding materials, but also elaborate the EMI shielding mechanisms and the index for "green EMI shielding" performance. In addition, the construction strategies for sophisticated multifunctionalities of flexible shielding materials are summarized. Finally, we propose several possible research directions for flexible EMI shielding materials in near future, which could be inspirational to the fast-growing next-generation flexible electronic devices with reliable and multipurpose protections as offered by EMI shielding materials. 

https://link.springer.com/content/pdf/10.1007/s40820-022-00823-7.pdf

Recent Advances in Design Strategies and Multifunctionality of Flexible Electromagnetic Interference Shielding Materials

Construction of multiple interfaces and dielectric/magnetic heterostructures in electromagnetic wave absorbers with enhanced absorption performance: A review

Effective nondestructive evaluations on UHMWPE/Recycled-PA6 blends using FTIR imaging and dynamic mechanical analysis

Additive manufacturing (AM), also known as three-dimensional (3D) printing, is thriving as an effective and robust method in fabricating architected piezoelectric structures, yet most of the commonly adopted printing techniques often face the inherent speed-accuracy trade-off, limiting their speed in manufacturing sophisticated parts containing micro-/nanoscale features. Herein, stabilized, photo-curable resins comprising chemically functionalized piezoelectric nanoparticles (PiezoNPs) were formulated, from which microscale architected 3D piezoelectric structures were printed continuously via micro continuous liquid interface production (μCLIP) at speeds of up to ~60 μm s−1, which are more than 10 times faster than the previously reported stereolithography-based works. The 3D-printed functionalized barium titanate (f-BTO) composites reveal a bulk piezoelectric charge constant d33 of 27.70 pC N−1 with the 30 wt% f-BTO. Moreover, rationally designed lattice structures that manifested enhanced, tailorable piezoelectric sensing performance as well as mechanical flexibility were tested and explored in diverse flexible and wearable self-powered sensing applications, e.g., motion recognition and respiratory monitoring.

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Wenbo Wang

Papers

Effective nondestructive evaluations on UHMWPE/Recycled-PA6 blends using FTIR imaging and dynamic mechanical analysis

Continuous Three-Dimensional Printing of Architected Piezoelectric Sensors in Minutes

Morphology characterization and the phase separation behavior of UHMWPE/recycled‐PA6 blends using FTIR imaging and thermomechanical analysis

Adsorption Experiments and Kinetics of an Efficient Absorbent for Cd(II)