What is EMI shielding?
Electromagnetic interference shielding is the action of surrounding electronics and cables with conductive or magnetic materials to guard against incoming or outgoing emissions of electromagnetic radiation, that can interfere with their proper operation.
The shielding can reduce the coupling of radio waves, electromagnetic fields and electrostatic fields (EM shielding that blocks radio frequency electromagnetic radiation is also known as RF shielding). The amount of reduction depends heavily upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of apertures in a shield to an electromagnetic field.
What is EMI shielding used for?
EMI shielding is done for several reasons, but the most common goal is preventing electromagnetic interference (EMI) from affecting sensitive electronics. Metallic mesh shields are often used to protect one component from affecting another inside a device.
Air gapped systems, usually used by military, government and financial institutions, can also benefit from EM shielding. Although physical isolation and a lack of external connectivity are often considered adequate to ensure the system’s security, several methods have been shown to successfully exploit the electromagnetic radiation that comes from different parts of the system.
How is EMI shielding done?
Various different materials and techniques are used for EM shielding. Wires may be surrounded by a metallic foil or shield to block EM emanations from the cased wires. Audio speakers often have inner metallic casing to block EMI produced by the drivers so they don’t affect TVs and other electronics. EMI filters are also found in electronic components, and more. Certain techniques are similar in concept to a Faraday cage, preventing signal corruption that would cause electronics to perform badly. Mesh can be used as total enclosure is not necessary if the openings are smaller than the electromagnetic waves that need to be blocked.
Typical materials used for electromagnetic shielding include sheet metal, metal screen, and metal foams. other shielding methods (especially used in electronic goods put in plastic enclosures) involve metallic inks that consist of a carrier material loaded with a suitable metal, typically copper or nickel, in the form of very small particulates. Copper is used for radio frequency (RF) shielding because it absorbs radio and magnetic waves.
Graphene EMI shielding
EMI shielding methods traditionally rely on metal, which adds weight and is expensive. A significant body of research demonstrates that carbon nanostructure-based nanocomposite materials can outperform conventional metal shielding due to their light weight, resistance to corrosion, flexibility, and processing advantages. On top of all these, graphene’s excellent conductivity makes it a perfect candidate for such applications.
The latest graphene EMI shielding news:
Graphenest has launched two products, based on a proprietary graphene production method, now available to pre-order with a campaign price for a limited time.
The first product is HexaShield, a graphene-based paintable coating for RF electromagnetic interference (EMI) and radiation shielding. It reportedly provides drastic weight reduction, and reduced manufacturing cost as compared to metals, while achieving the required protection for the Gigahertz frequency range.
Versarien has announced its plans to enter an agreement with a large state-owned Chinese aerospace company. The Partner is said to mainly be engaged in the research, design, manufacture and operation of various aerospace systems.
The agreement details the parties' desire to collaborate and ultimately enter into a strategic cooperation covering research, development and manufacturing in order to accelerate the industrialization and market for graphene and other Versarien 2D materials, including Hexotene, in the Chinese aerospace sector. This will include exploring their uses within the fields of, amongst others, microwave and electromagnetic radiation shielding, heat dispersion coatings, 3D printing and flexible wearable devices.
A collaboration between two innovative material technology startups Graphmatech and Add North 3D (a Swedish 3D materials developer specialized in FDM materials) has developed novel conductive Aros Graphene-based filaments for 3D printing. This may open up many new different 3D-printing applications such as thermal management components, circuit boards and efficient electromagnetic and radio frequency shielding.
The recently developed 3D-printing technology based on Graphematech's Aros Graphene may grant the ability to control the exact level of conductivity of the filament. The new filaments will now be optimized and go through beta testing with a reference group before it is expected to reach the market in 6-12 month.
Australia-based advanced materials company Talga Resources has reported high levels of electrical conductivity in concrete by using an additive developed from the Company’s graphene-graphite research and development laboratory in the UK.
The reported breakthrough offers substantial potential in existing and emerging industrial applications, particularly as concrete is the world’s largest construction material by volume. Talga shared information gathered from tests that show that the graphene-enhanced concrete is highly electrically conductive - attaining 0.05 ohm.cm volume resistivity.
The PolyGraph project, a 4-year development project with aims to develop new production techniques to deliver industrial scale quantities of graphene-reinforced thermosetting polymers, has published its results.
The POLYGRAPH (Up-Scaled Production of Graphene Reinforced Thermosetting Polymers for Composite, Coating and Adhesive Applications) project brought together 14 partners, including SMEs, companies, universities and a research center, and has reportedly led to the identification of the most suitable materials and production techniques for graphene-based coatings, adhesives and composites. Once the graphene market reaches maturity and material prices drop , these new products could appeal to a vast range of industries.