Aug, 18 2021

EMI Shielding for eVTOL Aircraft



EMI Shielding for eVTOL Aircraft

Electric vertical takeoff and landing (eVTOL) aircraft need reliable shielding against electromagnetic interference (EMI) and dependable environmental sealing. Although the brushless DC motors that are used with eVTOL aircraft do not generate significant amounts of EMI, these motors are not altogether free from electronic noise. Moreover, because eVTOL development is coincident with 5G, eVTOL aircraft are expected to use densely-packed circuits that are susceptible to cross-talk and that generate high heat.

Whether it’s caused by DC motors or other electronic circuits, EMI can disrupt communications between eVTOL aircraft and control centers. Heat, the enemy of electronics, is typically handled at the printed circuit board (PCB) level but is too much of risk for eVTOL designers to ignore. Environmental sealing against water, weather, sunlight, and ozone is also required. Consequently, EMI silicones that combine shielding with heat resistance and environmental sealing are materials that eVTOL engineers need.           

eVTOL Market Predictions and Opportunities

According to the research and consultancy firm IDTechEx and as reported in Composites World, the global market for eVTOL aircraft is expected to reach $14.7 billion (USD) by 2041. That  estimate may be too low – and by a significant amount. Morgan Stanley has revised its own previous estimate downward, but the global investment bank and financial services company still expects the market for eVTOL aircraft to reach $1 trillion (USD) by 2040.

Both companies cite urban air mobility (UAM) as a leading driver of demand. Improvements in battery technology and propulsion architectures represent are still steep development hurdles, but the sky’s the limit (literally) in terms of opportunities. As Morgan Stanley explains in a new report, freight shipments ranging from smart parcels to full-size pallets are a compelling eVTOL use case. There’s also potential overlap with short-haul passenger aircraft and potential military applications.     

Leading developers of eVTOL aircraft include Archer, Beta Technologies, Joby Aviation, and Wisk. Using today’s battery technologies, Archer has developed a five-passenger vehicle that can travel up to 60 miles at speeds of up to 150 mph. Beta Technologies recently received military airworthiness approval from the U.S. Air Force and Joby Aviation just became the first publicly-traded U.S. eVTOL company. Wisk prides itself on completing over 1,500 flights and forging a partnership with NASA last year.

EMI Silicones and eVTOL Aircraft

Specialty Silicone Products (SSP), a leading provider of EMI silicones, makes particle-filled elastomers that can be fabricated into seals, gaskets, and O-rings for electronic connectors, avionics, global positioning systems (GPS), light detection and ranging (LiDAR), battery packs, and other eVTOL components, assemblies, sub-assemblies, and systems. SSP also makes low-outgassing silicones that won’t cloud the optics used in eVTOL cameras and fluorosilicones that resist swell for contact with glycol de-icing fluids.  

With electronic connectors, particle-filled silicones that are ready-to-mold can be overmolded for EMI shielding and environmental seals. Compression-molded sheet stock and continuous rolls can be die cut or water jet cut into EMI gaskets for enclosure sealing and shielding. SSP’s custom molded EMI gaskets mean lower lead times and lower tooling costs while its bonded EMI O-rings can match molded one in terms of reliability and performance. In addition to their heat and environmental resistance, SSP’s EMI silicones provide good compressibility and come in a range of durometers, including softer materials.

All of these shielding elastomers offer reliable electrical conductivity. Many meet the MIL-DTL-83528 standard and some proven flame resistance. Today, two SSP elastomers are replacing discontinued GORE® materials in the aviation marketplace and of particular interest to eVTOL designers. Both compounds are filled with nickel-graphite particles and conform to UL-94 V0, a leading flammability standard that is used in the aircraft industry and other applications (such as automotive) where passenger safety is critical.

SSP-502-40-V0 is a 40-durometer EMI silicone that is an offset to GORE GS2100. SSP-502-60-V0 is a 60-durometer material that is an offset to GORE GS5200. Both of these elastomers have been tested to ASTM 595 outgassing parameters with and without a conductive pressure-sensitive adhesive (PSA) applied. By using EMI gaskets with a PSA adhesives, eVTOL companies can speed assembly for reduced operational costs – and important consideration in highly competitive marketplace.  

Contact SSP for eVTOL Shielding and Shielding

Specialty Silicone Products of Ballston Spa, New York is an ISO 9001:2015 certified company with a 25+ year history of solving difficult challenges for demanding industries that include aerospace and defense. All of our products are proudly Made in the USA with lower minimum order quantities (MOQs) and shorter lead times that other suppliers of EMI silicones can offer. For more information about SSP’s products and capabilities, contact us on-line or email Dominic Testo, SSP’s Business Development Manager.