Carbon nanotubes offer lightweight EMI shielding

Carbon nanotubes offer lightweight EMI shielding

Nanotube technology has been getting a lot of positive buzz lately, which has been well deserved. Carbon nanotubes (CNTs) in particular with their unique structural, electrical, and thermal properties have been grabbing attention for their wide range of potential uses. Increasing the tensile strength of materials (for concrete and body armor), use as a charge storage medium (for supercapacitors and batteries), and the conduction of heat (as a heat sink or flame barrier) are just a few of the applications that exemplify this diversity.

Another area where CNTs are being looked at more extensively is for EMI shielding. Research efforts are being spearheaded by companies in the military, aviation, and aerospace fields where effective shielding of sensitive electronic equipment is critical. In these applications, EMI not only can cause equipment to malfunction, but it can jam radar and radio signals, cause data and memory loss, and inhibit computer connectivity and telecommunication links.

Current research indicates that by creating composite materials composed of a polymer-medium coated or impregnated with CNTs can be an effective EMI shield especially for higher frequencies. Testing this material has also shown that EMI reflection and absorption qualities can be manipulated by a number of factors. These factors include the thickness of the composite material, the density of CNT in the medium, the nature of the CNT structure, and the specific medium used.

Additionally, the composite material is extremely lightweight, making it an attractive alternative to heavier, metal-based shielding. Extensive use of the composite material in wires, cables, connectors and housings can significantly lower the overall weight of a vehicle. This can directly translate into reduced fuel consumption and improved operational control.

In related news, a partnership group composed of NASA, the DOE, and the NIA recently released the intellectual property rights to a nanotube technology called fibril boron nitride nanotubes (BNNTs.) The jointly developed material is similar in nature to carbon nanotubes yet with inherently better properties. The group expects that licensing the technology into the commercial sector will increase production rates and hasten application testing. It is another good indicator that nanotube technology is steadily on the rise.

Michael J. Kawa