Flexible multilayer magnetic composite for EMI shielding and radiation monitoring

Background

Across sectors such as aerospace, automotive, and healthcare, protection against ionizing radiation and electromagnetic interference is essential. Satellites, aircraft, medical imaging devices, and electric vehicles require materials that shield sensitive electronics and biological tissues from charged particles, ultraviolet exposure, and stray electromagnetic fields. Conventional rigid enclosures and heavy metallic shields increase weight, restrict design flexibility, and add cost, driving demand for novel solutions that combine thin form factors, mechanical compliance, and stable performance across cryogenic to elevated temperature environments.

Existing approaches typically rely on thick metal foils, conductive paints, or bulk ceramics, which suffer from brittleness, limited operational ranges, and lack real-time diagnostics. Metal sheets and alloys offer good attenuation but are inflexible and prone to corrosion, while conductive coatings degrade under repeated thermal cycling and charged-particle bombardment. Most systems cannot indicate cumulative radiation damage or electromagnetic stress, necessitating frequent inspection or replacement. Moreover, the opacity of these materials precludes their use in viewports and display windows, and their permanent installation hinders rapid reconfiguration or reuse in dynamic applications.

Technology

This bi-layer or multilayer assembly consists of an ultra-thin flexible substrate—such as aerogel, flexible ceramic, or siloxane-based polymer—coated with a 5–100 nm permalloy (Ni80Fe20) ferromagnetic film. An optional co-sputtered layer of molybdenum, ruthenium, or tungsten enhances corrosion resistance, while an interfacial adhesion layer and alloy impregnation into the substrate boost bonding and shielding performance. Substrates are fabricated via sol-gel supercritical drying or room-temperature crosslinking to yield porous, transparent films. Continuous monitoring of cumulative UV, charged‐particle, or EMI exposure is achieved through non-destructive Kerr or Faraday effect measurements. Full encapsulation and integrated temperature or shock sensors enable operation from cryogenic to high-temperature environments in a reusable, non-invasive platform.

Unlike traditional metallic conductor shields, this flexible, lightweight system maintains optical transparency and conforms to complex geometries. Its direct impregnation of magnetic alloy into a porous substrate minimizes mass while maximizing charged‐particle absorption and EMI attenuation. The ability to pattern the magnetic layer and co-sputter corrosion-resistant metals yields a customizable performance profile. Real-time monitoring via Kerr or Faraday signals provides embedded sensing capability absent in static shields. With a wide operating temperature range (cryogenic to 1300 °C) and detachable encapsulation, it delivers cost-effective scalability for aerospace, automotive, and healthcare applications, outperforming bulk, rigid alternatives.

Benefits

• Lightweight, flexible shielding platform suitable for conformal applications
• Transparent design ideal for visors, windows, and optical systems
• Wide operating temperature range from cryogenic to 1300 °C
• Integrated non-destructive monitoring of radiation and EMI via Kerr/Faraday effects
• Reusable, removable and customizable to complex shapes and geometries
• Low-cost, scalable manufacturing using sol-gel and DC magnetron sputtering
• Corrosion-resistant permalloy alloy coating for enhanced durability
• Multifunctional capability with added temperature and shock sensing

Applications

• Spacecraft radiation shielding
• Electric vehicle EMI protection
• Medical imaging equipment shielding
• Transparent electronic window shielding
• Wearable device electromagnetic shielding

Additional info

A bi-layer assembly couples a thin flexible porous substrate (siloxane polymer, aerogel or 20 μm YSZ) with a DC magnetron sputtered 5–100 nm Ni80Fe20/Mo,Ru,W ferromagnetic film. Impregnation and interfacial adhesion layers enhance bonding while sol-gel supercritical drying or room-temp crosslinking yields transparency. Kerr/Faraday effect–based monitoring tracks cumulative UV/particle/EMI exposure. Full encapsulation ensures operation from cryogenic to 1300 °C, and integrated temperature/shock transducers enable reusable, customizable radiation and EMI shielding with real-time sensing.