Structural Electromagnetic Absorber Based on MoS₂/PyC‐Al₂O₃ Ceramic Metamaterials

Abstract

Limited by the types of suitable absorbents as well as the challenges in engineering the nanostructures (e.g., defects, dipoles, and hetero‐interface) using state‐of‐the‐art additive manufacturing (AM) techniques, the electromagnetic (EM) wave absorption performance of the current ceramic‐based materials is still not satisfying. Moreover, because of the high residual porosity and the possible formation of cracks during sintering or pyrolysis, AM‐formed ceramic components may in many cases exhibit low mechanical strength. In this work, semiconductive MoS2 and conductive PyC modified Al2O3 (MoS2/PyC‐Al2O3) ceramic‐based structural EM metamaterials are developed by innovatively harnessing AM, precursor infiltration and pyrolysis (PIP), and hydrothermal methods. Three different meta‐structures are successfully created, and the ceramic‐based nanocomposite benefit from its optimization of EM parameters. Ultra‐broad effective absorption bandwidth (EAB) of 35 GHz is achieved by establishment of multi‐loss mechanism via nanostructure engineering and fabrication of meta‐structures via AM. Due to the strengthening by the PyC phase, the bending strength of the resulting ceramics can reach ≈327 MPa, which is the highest value measured on 3D‐printed ceramics of this type that has been reported so far. For the first time, the positive effect deriving from the engineering of the microscopic nano/microstructure and of the macroscopic meta‐structure of the absorber on the permittivity and EM absorption performance is proposed. Integration of outstanding mechanical strength and ultra‐broad EAB is innovatively realized through a multi‐scale design route. This work provides new insights for the design of advanced ceramic‐based metamaterials with outstanding performance under extreme environment.

Structural Design for EMI Shielding: From Underlying Mechanisms to Common Pitfalls

“…Utilizing the DLP 3D-printing technique, Liu et al have innovatively developed MoS 2 and pyrolytic carbon-modified Al 2 O 3 (MoS 2 /PyC-Al 2 O 3 ) ceramic-based structural electromagnetic metamaterials. [180] This approach leverages advanced manufacturing processes, including additive manufacturing with precursor infiltration and pyrolysis and hydrothermal methods, to fabricate three distinct metastructures. These nanocomposites achieve an ultrabroad effective absorption bandwidth of 35 GHz through the engineering of nanostructures.…”

MoS2-Based Nanocomposites for Microwave Absorption: A Review

“…26,27 The world's military powers have invested a lot of research in the field of stealth and have made certain progress, such as radar stealth, aircraft stealth, and military weapon stealth. 28,29 The main way to achieve stealth technology is to reduce the radar cross section and reduce its own infrared radiation. 30,31 Furthermore, the key to the realization of stealth technology is to design materials suitable for weapons and coat these materials on the surface of weapons to reduce the radar cross section and absorb the electromagnetic wave incident on the surface of weapons, so that weapons and equipment could achieve stealth.…”

“…When electromagnetic radiation exceeds a certain range, it will seriously affect the human immune system and damage health. − In fact, most people’s lives are surrounded by various electronic devices, such as mobile phones, laptops, tablet computers, microwave ovens, etc., which makes people’s living environments seriously affected by electromagnetic waves. − Serious electromagnetic interference could also affect radar, wired electrical equipment, communication, and navigation systems, which could easily lead to equipment failures and safety accidents. On the other hand, stealth materials play an important role in the military field. , The world’s military powers have invested a lot of research in the field of stealth and have made certain progress, such as radar stealth, aircraft stealth, and military weapon stealth. , The main way to achieve stealth technology is to reduce the radar cross section and reduce its own infrared radiation. , Furthermore, the key to the realization of stealth technology is to design materials suitable for weapons and coat these materials on the surface of weapons to reduce the radar cross section and absorb the electromagnetic wave incident on the surface of weapons, so that weapons and equipment could achieve stealth. Therefore, whether in the military field or the civilian field, research on microwave absorption materials with excellent performance has become an urgent need on today’s society. ,,− …”

UV-modification of Ag nanoparticles on α-MoCx for interface polarization engineering in electromagnetic wave absorption

“…7,8 Electromagnetic wave materials have a wide range of applications in EMI (electromagnetic interference) shielding [9][10][11] and civilian-military stealth coatings [12][13][14][15] and have thus attracted significant attention. As representative EWAMs, carbon-based composite materials, [16][17][18][19][20][21][22][23][24][25][26][27] transition metallic composites, [28][29][30][31][32][33][34][35] and non-metallic ceramic compounds [36][37][38][39][40] have shown high electromagnetic wave absorption and wide band coverage performances.…”