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:
Versarien has announced the launch of a new hybrid nanomaterial that has superparamagnetic properties, which can be used across a range of applications, like defense and healthcare. The new material combines graphene with both iron oxide and manganese oxide nanoparticles and its development was led by Versarien's 62% owned subsidiary, Gnanomat.
The superparamagnetic material combines graphene with both iron oxide and manganese oxide nanoparticles that provide the material with magnetic properties. In return, graphene provides electrical conductivity to these electrically insulating metal oxides. Magnetic nanocomposites can readily respond to external magnetic fields which allow them to be manipulated. Potential applications of the material include the treatment of wastewater whereby pollutants are adsorbed onto the graphene surface. The material could also lends be used in biomedical and biotechnology applications, or defense applications requiring the shielding of electromagnetic fields. Magnetic manipulation could allow the recovery and recycling of the graphene, something that could not be done with normal graphene compounds.
Graphenest teams up with Delta Tecnic for the commercialization of graphene-based EMI shielding products
Graphenest and Delta Tecnic have announced a strategic partnership that will explore the commercialization of graphene-based polymer compounds with "unprecedented electromagnetic interference (EMI) shielding performance".
This new product line already includes a PVC material that reportedly has extremely good electrical features that make it suitable for use as an EMI shielding solution in the cable industry.
Poland-based nanoEMI announced that it has raised around 250,000 Euro in its seed round, from GT Technologies, a Poland-based VC. The company says that the funds will help it scale up its production capabilities for graphene and composite materials.
nanoEMI focuses on EMI shielding applications, and produces its own graphene using two different methods (exfoliation in isopropyl alcohol and in castor oil), at its own pilot production line.
U.S-based graphene batteries developer Nanotech Energy is reportedly planning to expand its facilities and develop a 517-acre campus within the Tahoe Reno Industrial Center. The first building is slated to open in Q4 2022.
The high-volume facility will significantly increase Nanotech Energy’s manufacturing capacity to produce and scale its patented, non-flammable Graphene-Organolyte™ batteries and other graphene-powered products, including EMI (electromagnetic interference) shielding, transparent conducting electrodes, conductive inks, conductive adhesives and silver nanowires.
NanoEMI, A Poland-based company working on graphene-based EMI shielding applications, recently announced that it was selected by Startup Spark accelerator at Lodz Special Economic Zone to work with Ericsson on validation of its technology in innovative telecommunication devices.
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. Graphene-based EMI shielding is an interesting area of focus, and recent advances include Nanotech Energy's announcement of the debut of its EMI Armor Paint & Sheets, graphene powered coatings and films for electromagnetic interference (EMI) and radio frequency interference (RFI) shielding, as well as heat management.