Highly flexible electromagnetic interference shielding films based on ultrathin Ni/Ag composites on paper substrates

Abstract

Highly flexible electromagnetic interference (EMI) shielding material with excellent shielding performance is of great significance to practical applications in nextgeneration flexible devices. However, most EMI materials suffer from insufficient flexibility and complicated preparation methods. In this study, we propose a new scheme to fabricate a magnetic Ni particle/Ag matrix composite ultrathin film on a paper surface. For a ~2 µm thick film on paper, the EMI shielding effectiveness (SE) was found to be 46.2 dB at 8.1 GHz after bending 200,000 times over a radius of ~2 mm. The sheet resistance (R□) remained lower than 2.30 Ω after bending 200,000 times.Contrary to the change in R□, the EMI SE of the film generally increased as the weight ratio of Ag to Ni increased, in accordance with the principle that EMI SE is positively related with an increase in electrical conductivity. Desirable EMI shielding ability, 2 ultrahigh flexibility, and simple processing provide this material with excellent application prospects.

Ink-Coated Silver Films on PET for Flexible, High Performance Electromagnetic Interference Shielding and Joule Heating

“…The p-value for tape tests is 0.14 and for twisting is 0.46, which both support the null hypothesis of no change in R s /R sd o considering a significance level of α = 0.05. 18 Ni/Ag composite, 14 PU/CNT composite, 40 PU/FeCo@rGO, 41 Ag nanowire, 11 MXenes/Polyester, 22 Ag nanowire/cellulose, 23 Ag−Ni mesh, 21 3D graphene with Ni NPs, 21 CEF-NF/Ag/WPU film, 39 nanoporous Ag membranes, 42 Ag foil, 42 and Cu foil. 42 When a voltage is applied to a conductor, electrons collide with phonons leading to the generation of heat.…”

“…The silver ink consists of a reactive silver ink, which can achieve high conductivities at low curing temperatures. 35 Coated samples with a thickness of 11.7 μm were observed to have sheet resistance as low as 56.9 mohm/sq and SE as high as 82.6 dB EMI in the X band (8−12 GHz) and 85.3 dB EMI in the Ku band (12)(13)(14)(15)(16)(17)(18). Without the PUD, the silver films crack after a single bend.…”

“…Traditional EMI shielding consists of metal cages, foils, and meshes. − However, these materials are thick, heavy, bulky, and rigid and are unsuitable for flexible electronics and wearables . Conventional EMI shielding is fabricated by subtractive manufacturing methods such as die cutting, extrusion, or molding, which consume much material and energy and their cost is high. , New lightweight EMI shielding materials are needed that may accommodate a variety of substrates including polyethylene terephthalate (PET) for flexible electronics or textiles for wearable electronics. , …”

Recent Advances in Design and Fabrication of Nanocomposites for Electromagnetic Wave Shielding and Absorbing

“…When an EM wave transmits onto the shield, there exists the possibilities of absorption, reflection, and transmission of the EM wave, whose coefficients are denoted by A, R, and T, respectively, indicating the responses of the shielding to the incident EM wave [ 25 ]. The reflective part of the EM wave is comprised of reflection from the shielding material surface and the secondary reflection in the internal of materials, which tends to happen on the high conductivity surface with a large number of charge carriers [ 26 ].…”

Paper-based printed CPW-fed antenna for Wi-Fi applications

“…Paper is one of the most widely used, inexpensive, and commonly available materials [1]. It has recently been used extensively as a flexible substrate for fabricating electronic devices, more popular as "paper-based electronics" [2][3][4][5]. It possesses excellent biodegradable properties.…”