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Yan et al. Soft Sci. 2025, 5, 8 https://dx.doi.org/10.20517/ss.2024.66 Page 3 of 34

Scheme 1. Schematic diagram of the article structure.

of the article is shown schematically in Scheme 1). Additionally, the review also deeply researches and
analyzes the fundamental methods and mechanisms of EMW energy conversion and dissipation in various
situations, and finally gives an outlook on their development trends and challenges, which provides certain
guidance for the design, development, and application of novel EMI shielding composites with thermal
management.

FUNDAMENTAL MECHANISMS OF EMI SHIELDING
EMI shielding refers to the prevention of EMWs from propagating through the transmission path. The
degree of attenuation of EMWs is represented by shielding effectiveness (SE) [56,57] . According to
Schelkunoff’s theory of plane-wave electromagnetic transmission, when an EMW reaches the surface of a
shielding material, part of the wave is directly reflected (SE ) due to an impedance mismatch, while the
R
remainder enters the material. Within the material, attenuation occurs due to absorption (SE ) and multiple
A
reflections (SE ) [typically, SE is negligible when the SE (SE ) exceeds 15.00 dB] [58-60] . Finally, the residual
M
M
T
EMW passes through the shielding layer, during which the attenuation process of the shielding material for
the EMW includes reflection, absorption, and internal multiple reflection loss, and the electromagnetic
shielding capability is expressed in terms of the SE (SE ), which is given by
T
SE = SE + SE (1)
R
A
T
The shielding behavior of a material is usually obtained from the S-parameters (S , S , S , S ), according to
11
12
21
22
which the corresponding reflection loss (R), absorption loss (A), and emission loss (T) can be calculated by
R = |S | = |S | 2 (2)
2
11
22
T = |S | = |S | 2 (3)
2
21
12