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Guide to EMI Shielding Materials

Electromagnetic interference, or EMI, is a signal from one device that disrupts the signal of another device. This signal can cause a decrease in system performance, loss of functionality, or permanent damage. EMI shielding prevents electromagnetic interference from emitting from or entering a device, providing protection from the negative effects of EMI.

Here, we will explore EMI shielding and the various types of materials it can be made from to deliver optimal protection for your devices and systems.

Understanding EMI Shielding

EMI shielding protects an electronic device from external signal interference and prevents the device from interfering with surrounding devices, ensuring all intended signals are clean and functional. EMI shielding materials are typically metallic, allowing them to conduct and absorb the interference signal before it reaches the electronic components within the protected device.

Various industries depend on EMI shielding to protect electronic devices and systems from interference. EMI shielding enables the proper functionality of consumer electronics, automobiles, satellites, medical devices, and many other electronic systems.

Types of EMI Shielding Materials

Various EMI shielding materials provide reliable protection from interference, including solid metals, conductive paints and coatings, specialized plastics, and metallic foils.


The following metals are ideal EMI shielding materials:

  • Copper: A reliable metal for EMI shielding applications, copper can reduce interference from electrical and magnetic waves with their high electrical conductivity. Copper is an ideal material for nearly every EMI shielding application and is commonly used in everything from home computers to critical healthcare equipment. However, copper can be significantly more costly than other materials.
  • Aluminum: This material offers good electrical conductivity and an excellent strength-to-weight ratio. Aluminum is more prone to oxidation and corrosion than other alloys, but it is a suitable option for applications requiring a non-ferrous EMI shielding material. Aluminum offers about 60% of the electrical conductivity of copper, but it is less expensive.
  • Steel: Various types of steel, including stainless steel, carbon steel, and other steel alloys, are suitable EMI shielding materials. Carbon steel offers magnetic shielding and can be pre-tin plated to protect against low-frequency EMI and corrosion at a low cost.

Conductive Coatings and Paints

Conductive paints and coatings can give EMI shielding properties to materials that typically do not provide shielding, such as drywall and wood.

  • Silver-filled coatings: This smooth and brightly colored coating offers exceptional conductivity and adhesion to various plastics and metals. Silver-filled coatings can comply with UL requirements and work for EMI shielding on medical, scientific, military, and industrial equipment as well as personal computers and mobile device enclosures.
  • Nickel-based coatings: Nickel-based coatings offer excellent corrosion resistance and are available in easy-to-apply liquid and aerosol formats. Its mild solvent composition is safe for use on polystyrenes, contains no hazardous air pollutants (HAP), and can comply with UL requirements. Nickel-based coatings are ideal for marine EMI shielding applications and can coat plastics, wood, and drywall.
  • Graphite-based paints: These paints offer low surface resistivity, high conductivity, durability, good adhesion, and corrosion resistance. Graphite-based paints resist rub-off and weather and are a cost-effective solution for low-frequency EMI shielding. They can be applied to wood, drywall, metal, glass, and plastics.

Conductive Plastics and Polymers

Plastics and polymers can be made to conduct electrical and magnetic signals to provide EMI protection. The following plastics and polymers are used in EMI shielding.

  • Carbon-filled plastics: This EMI shielding option synthesizes the benefits of traditional metals as well as the reduced weight, better flexibility, and enhanced corrosion resistance of plastics. Carbon-filled plastics are cost-effective solutions for critical applications requiring design flexibility, including military, medical, aerospace, and consumer electronics equipment.
  • Metal-coated polymers: Metal-coated polymers are lightweight, versatile plastics with conductive EMI shielding properties. They are typically more cost-effective and flexible in design than solid metal shields.

EMI Shielding Expanded Metal Foil

The EMI shielding effectiveness of a conductive material depends on the thickness and type of material, the strength and frequency of the electromagnetic signal, and the design of the shield itself. Although thick, solid conductive materials tend to offer superior shielding, they can also be heavier and more costly. EMI shielding with expanded metal foil offers a cost-effective, lightweight alternative to solid metal shields.

Made from copper, aluminum, or other conductive metal, expanded metal foil is versatile, flexible, and malleable, allowing the user to install the foil around the surface of various objects. The expanded metal foil prevents EMI from harming the protected device and surrounding electronics.

Precision expanded metal foils from CThru Metals conduct the interfering signal across the surface of the material, maintaining the functionality of wires, cables, gaskets, enclosures, electrical systems, carbon fiber products, and more. It is a reliable, lightweight solution, especially in demanding aerospace and defense industry applications.

Protect Your Electronics With CThru Mesh™ Precision Expanded Metal Foils

EMI is a disrupting signal from nearby sources that can interfere with sensitive electrical components. EMI shielding can prevent the harmful effects of electromagnetic interference by conducting the interfering signals and carrying them away from the sensitive components. There are various EMI shielding materials available, including solid metals, coatings, paints, specially designed plastics, and expanded metallic foils.

CThru Metals manufactures precision expanded metal foils for cost-effective, lightweight EMI shielding in various applications. Based on your specific application, we can customize your custom EMI shielding foil by thickness, material, opening dimensions, number of openings, and more. Contact us or request a quote for more information about CThru Mesh™ precision expanded metal foils.

What Is EMI Shielding?

CThru Metals is a leader in the expanded metal foil industry, serving clients in the aerospace, filtration, renewable energy, automotive, and other markets. The applications of expanded metals in these sectors are highly diverse, so our team is experienced in providing all manner of specialized metals with unique specifications. One of the core applications of expanded metal foils is electromagnetic interference (EMI) shielding.

This blog will explore what EMI shielding is, the industries that use EMI shielding, and more.

What Is EMI Shielding?

What Is EMI Shielding?

EMI shielding refers to a type of protection against electromagnetic waves. All electronic devices emit some amount of electromagnetic energy, which may cause devices to interfere with each other if they are not properly safeguarded against these waves. The interference can result in mixed signals, static, and device malfunction.

EMI shielding is typically a conductive piece of metal affixed around the electronic components that give off electromagnetic signals. This form of shielding is required for devices to have electromagnetic compatibility (EMC), which means they operate efficiently and legally.

The Importance of EMI Shielding

The modern age is defined by electronic technology. From televisions to lighting to cell phones, all of them can potentially be affected by electromagnetic interference unless they are properly shielded. Increased data processing and communication demands represent additional sources of electromagnetic noise pollution. Even solar flares and lightning strikes can cause EMI disturbances in electrical distribution and transmission systems.

Without EMI shielding, we wouldn’t be able to take advantage of new electronic innovations because they would be inconvenient or even hazardous to use. EMI shielding blocks external waves from disrupting a device’s internal parts while preventing those internal components from disrupting other devices. Shielding protects devices in contact with one another (conducted EMI), those not in direct contact but in close proximity (magnetic and capacitive EMI), and those separated by longer distances (radiated EMI).

Industries That Utilize EMI Shielding

Any industry that utilizes electronics makes use of EMI shielding in some form. Some examples include the following:

  • Aerospace
  • Automotive
  • Consumer Electronics
  • Healthcare
  • Medical Devices
  • Telecommunications and IT

Benefits of EMI Shielding

EMI shielding components are necessary in electronic devices because they minimize or eliminate harmful interference that can cause data loss, errors, device damage, and malfunction. EMI shielding also boosts the device’s performance by protecting it from external noise.

What Materials Act as EMI Shielding?

While any material that blocks EMI can act as shielding, the most effective material used in electronics is metal. Some common metals used in shielding components include the following:

  • Copper
  • Aluminum

EMI Shielding Products From CThru Metals

EMI shielding is a must for all electronic devices. CThru Metals’ Mesh™ expanded metal foils act as a Faraday cage to effectively block electromagnetic interference, keeping your signals clean and your devices functioning smoothly. Our team can work with you to create a custom configuration based on the EMI shielding needs of your application.

Our ISO 9001:2015 certification means we provide consistent high quality for every customer’s project. Request a quote today to get started on your solution.

Using Expanded Metal Foil in Fuel Cell Design

Fuel cell manufacturers are consistently dedicated to enhancing their products’ versatility, durability, and cost-effectiveness. They explore various methods to achieve these objectives, such as innovative designs and materials. An increasingly favored strategy among fuel cell manufacturers is the integration of expanded metal foil into their fuel cell designs, as it presents significant advantages in pursuing these goals.

CThru Mesh precision expanded metal foils find utility across multiple layers within a fuel cell stack. We’re committed to working closely with you to precisely manufacture your dimensional requirements, achieving the desired balance of conductivity and weight for your specific fuel cell needs.

Why Use Expanded Metal Foil in Fuel Cells

Using Expanded Metal Foil in Fuel Cell Design

When confronted with weight restrictions and the imperative to create the lightest possible fuel cell, opting for expanded metal foil is an ideal choice. This material, characterized by its remarkable combination of lightweight properties and robustness, requires a lower quantity of metal per unit area. The ability to eliminate scrap and employ lighter metals proves highly advantageous. Integrating expanded metal foil into your fuel cell applications can curtail material costs and elevate the performance and longevity of your product. Harnessing the potential of expanded metals can result in comprehensive enhancements to your product designs.

Benefits of Expanded Metal Foil in Fuel Cells

Implementing expanded metal foil into your fuel cell design offers the following benefits:

  • Versatility: The flexibility of expanded metal foil strongly appeals to manufacturers across diverse industries with various applications. Given that different types of fuel cells demand varying metals and specific properties, expanded metal foils provide the broadest range of options, capabilities, and resources.
  • Conductivity: Expanded metal foil crafted from a single solid metal sheet excel as conductors. Their conductivity remains consistent, unaffected by pressure-induced strand movement. This uniformity is critical for the efficiency of fuel cell stacks, ensuring consistent performance across cell layers. Expanded metals exhibit electrical conductivity and effectively conduct magnetic flux and thermal heat, further enhancing fuel cell performance.
  • Strength-to-Weight Ratio: The structural integrity of a metal is a key consideration in material selection for applications. However, opting for expanded metal foil over a solid metal sheet offers distinct advantages.
  • Maximized Surface Area at Reduced Costs: When working with precious metals like niobium, zirconium, nickel, silver, or titanium, expanding the metal foil minimizes material costs. Expanded metal foils are considerably more cost-effective than similar perforated or woven products.

Fuel Cell Applications

Expanded metal foil offers significant design advantages, accommodating thin foils of precious metals like nickel, titanium, zirconium, and silver. Fuel cell manufacturers continually prioritize enhancing their products’ versatility, durability, and cost-effectiveness. To achieve these goals, they explore various avenues, including innovative designs and the adoption of new materials. Many fuel cell manufacturers integrate expanded metal foils into their designs to achieve these objectives.

Custom Expanded Metal Foil Solutions From CThru Metals

When selecting an expanded metal foil company, it is important to choose a partner that understands and meets your needs and requirements. At CThru Metals, we collaborate closely with your team to identify the right material, size, and configurations for your expanded metal project. With our extensive experience in the expanded metal and metal fabrication industries, you can trust us to efficiently handle the job. Feel free to contact us for more information or to request a quote.