Intelligent shielding material based on VO2 with tunable near-field and far-field electromagnetic response

Tunable High-Performance Electromagnetic Interference Shielding of VO2 Nanowires-Based Composite

“…Moreover, the polarization loss (ε p ″) and conductivity loss (ε σ ″) were investigated to discuss the mechanism of dielectric loss (Figure S14), which can be expressed as the following equation formula ε ″ = ε p ″ + ε σ ″ = ε s − ε ∞ 1 + ω 2 τ 2 + σ ω ε 0 ε σ ″ = σ ω ε 0 = σ 2 π f ε 0 where ε s , ε ∞ , ε 0 , ω, τ, and σ represent the static permittivity and relative permittivity at the high-frequency limit, dielectric constant in vacuum, angular frequency, relaxation time, and electrical conductivity, respectively.…”

“…The ε σ ″ is much smaller than the ε p ″ in the temperature range of 30−70 °C, which indicates that the polarization loss is the primary 5c), indicating the existence of multipolarization relaxation processes. 25 Conversely, the existence of straight tails can be observed in the Cole−Cole curves of the VP-5 after the phase transition (Figure 5d), which indicates that the conductivity loss is relatively dominant. 37 In summary, the mechanism of EMI shielding switching between off and on states can be described as the coupling of polarization loss (ε p ″) and conductivity loss (ε σ ″) at different temperatures.…”

Controllable proton-reservoir ordered gel towards reversible switching and reliable electromagnetic interference shielding

“…4–6 Of particular interest are intelligent responsive EMI shielding materials, which exhibit the capacity to dynamically acclimate to evolving scenarios, rendering them exceptionally well-suited for the forthcoming demands in both civilian and military domains. 7,8 Under external stimulations such as temperature, 9–11 humidity, 12,13 voltage, 14,15 and stress, 16–18 the electromagnetic parameters of materials can undergo intrinsic changes. A recent breakthrough involves the development of pressure-actuated switch-type materials that exhibit dynamic and adaptable EMI shielding.…”

“…This approach inevitably significantly affects the reliability of its application in electronic devices. 9 Therefore, there is an urgent need to explore alternative external stimuli in order to develop highly advanced and intelligent EMI shielding materials that are both durable and reliable.…”

Realization of multifunctional transformation based on the vanadium dioxide-assisted metamaterial structure

“…In recent years, metamaterials have been widely applied in the control of electromagnetic waves, such as achieving electromagnetic invisibility, developing intelligent sensors, fabricating topological photonics devices, and other fields. 1–7 With in-depth research and exploration of metamaterials, vanadium dioxide (VO 2 ) has emerged as a popular material for controlling electromagnetic waves, 8,9 owing to its superior properties such as rapid response, temperature sensitivity, and infrared modulation. In specific applications, VO 2 can rapidly undergo a phase transition, known as metal–insulator transition (MIT), by applying external stimuli such as an electric field, 10 an optical field, 11 or a temperature field.…”