Apparatus and method for electromagnetic radiation shielding

Abstract

A multilayer substrate with coating that provides selective radiation shielding along with antifouling and antistatic capabilities. The substrates are customizable (e.g., lightweight, thin, flexible or rigid, robust, and may or may not be porous), and coated with a smooth, magnetic alloy as a blocking material for medium to high energy charged particle radiation and electromagnetic interference shielding. In one example, the substrate is a lightweight, flexible, and transparent substrate such as an aerogel, pm-thin flexible ceramic, or siloxane-based space-qualified polymers, coated with a a thin nickel-iron alloy based ferromagnetic film as an absorption media for medium to high energy charged particle radiation as well as electromagnetic interference (EMI) shielding.

Description

[0001] APPARATUS AND METHOD FOR ELECTROMAGNETIC RADIATION SHIELDING

[0002] This application claims benefit of and priority to U.S. Provisional App. No. 63 / 541,916, filed Oct. 2, 2023, which is incorporated herein in its entirety by specific reference for all purposes.

[0003] FIELD OF INVENTION

[0004] This invention relates to an apparatus, system, and related methods for enhanced electromagnetic (EM) shielding.

[0005] BACKGROUND OF INVENTION

[0006] Electromagnetic radiation has been regarded as an increasing hazard for commercial devices, biological systems, defense, and information technologies. This is also a major concern for long distanced manned missions and tire safety of astronauts. This is a result of their ability to instigate noise known as electromagnetic interference. Electromagnetic interference noise can lead +to faults in the operation of modem devices (for example, soft errors in integrated circuits) and to information leakage, as well as introducing novel security concerns in the aerospace industry. It also has been recently viewed as a potential health hazard.

[0007] Charged particle radiation exposure provides another challenge, with similar results: e.g., soft errors in electron devices, cellular damage, and increased cancer rates.

[0008] As a results, shielding materials and devices have grown into a multi-billion dollar industry. Current shielding technologies, however, afford several key drawbacks. More specifically, the majority of shielding devices on the market are composed of metallic conductors that lack flexibility. In addition, these devices typically have high masses and high costs due to the common materials used (i.e., Ag and Ag-alloys), and their single use / pennanent nature. Furthermore, these traditional metallic materials lack easy monitoring of exposure and degradation overtime, making failure prediction and total dose monitoring impractical.

[0009] Accordingly, what is needed is a shielding material that is flexible, lightweight, low-cost, and reusable, and that can be monitored in a non-destructive, remote manner allowing for failure prediction and dose monitoring while maintaining robust corrosion resistance.

[0010] SUMMARY OF INVENTION

[0011] Reduction and / or prevention of exposure to radiation (e g., ionizing, non-ionizing, cosmic, etc.) is critical in many industries, most notably healthcare, aerospace, and the auto (both EV and combustion engine) manufacturing industries. The invention comprises customizable substrates (lightweight, thin, flexible or rigid robust, porous or non-porous) coated with a smooth, magnetic alloy as a blocking material for medium to high energy charged particle radiation and electromagnetic interference shielding. This coating also experiences dose dependent changes to magnetic properties which may be measured through non-destructive remote sensing methods to afford total dose monitoring at points of potential exposure. The proposed technology goes beyond a superficial coating and can be designed such that the magnetic fingerprint is spread throughout the bulk of the material, leading to enhanced shielding. Tire invention can be utilized over a broad range of temperatures, cryogenics to 1000C. The substrate may be modified in order to influence the magnetic properties of the thin film.

[0012] Thus, in various exemplary embodiments, the present invention comprises a unique material / substrate combination which allows for flexible, lightweight, reusable and low-cost materials that can be monitored in a non-destructive, remote manner allowing for failure prediction and dose monitoring while maintaining robust corrosion resistance. More specifically, it provides selective radiation shielding capabilities combined with antifouling and antistatic capabilities.

[0013] In several embodiments, the invention comprises a bi-layer or multilayer structure comprising a lightweight, flexible, transparent, substrate (including, but not limited to, aerogels, pm -th in flexible ceramics, and siloxane -based space-qualified polymers) coated with a thin nickeliron alloy based ferromagnetic film as an absorption media for medium to high energy charged particle radiation as well as electromagnetic interference (EMI) shielding. Tire magnetic film is grown through DC-magnetron sputtering of permalloy (NisoFe2o) and co-sputtering to alloy permalloy with dilute amounts of other metallic layers to further enhance corrosion resistance (i.e. Mo, Ru, W), and can be designed such that the magnetic alloy is impregnated into the bulk of the host material, as shown in the figure, leading to enhanced shielding effects, as well as patterned into desired geometries dependent on the application. Monitoring of magnetic properties is done non-locally through measurements of the Kerr or Faraday effects (shown in the figures), providing a means to monitor the film integrity and exposure in a non-destructive manner, even in corrosive environments. The substrate can be prepared using sol-gel processes and dried under supercritical conditions. In another form, the substrate can be prepared by means of crosslinking and curing at room temperature. An interfacial layer to enhance bonding may be included for some applications. Furthermore, full encapsulation of the entire entity will be considered for applications in aerospace.

[0014] The invention includes three distinct aspects: (1) shielding and sensing combined into one device; (2) usage of fully cured and crosslinked substrates to serve as tire platfonn for tire magnetically active layer: and (3) combining other sensing forms (such as temperature and shock) with magnetic sensing capabilities. The invention is the creation of a robust multifunctional platform that combines sensing thin films with porous, flexible, transparent, and inert 3-D materials, to provide a low-cost light-weight alternative to expensive, rigid, heavy, and single-use shielding technologies currently used. The invention may be used to temporarily or permanently provide EM shielding through the encapsulation or enclosure at the desired location. The invention is removable, reusable, and non-invasive. It can be sized to the final shape and geometry desired by the end user. For example, a cube-shaped sensor can be placed adjacent to the electrical control units of electric and hybrid vehicles, to protect from interference.

[0015] BRIEF DESCRIPTION OF THE FIGURES

[0016] Figure 1 shows a cross-section of a multilayer material in accordance with an exemplary embodiment of the present invention.

[0017] Figure 2 shows an alternative embodiment of the multilayer material of Fig. 1.

[0018] DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

[0019] Reduction and / or prevention of exposure to radiation (e g., ionizing, non-ionizing, cosmic, etc.) is critical in many industries, most notably healthcare, aerospace, and the auto (both EV and combustion engine) manufacturing industries. The invention comprises customizable substrates 10 (lightweight, thin, flexible or rigid robust, porous or non-porous) coated with a smooth, magnetic alloy as a blocking material for medium to high energy charged particle radiation and electromagnetic interference shielding. This coating 20 also experiences dose dependent changes to magnetic properties which may be measured through non-destructive remote sensing methods to afford total dose monitoring at points of potential exposure. The proposed technology goes beyond a superficial coating and can be designed such that the magnetic fingerprint is spread throughout the bulk of the material, leading to enhanced shielding. The invention can be utilized over a broad range of temperatures, cryogenics to 1000C. The substrate may be modified in order to influence the magnetic properties of the thin film.

[0020] Thus, in various exemplary embodiments, the present invention comprises a unique material / substrate combination which allows for flexible, lightweight, reusable and low-cost materials that can be monitored in a non-destructive, remote manner allowing for failure prediction and dose monitoring while maintaining robust corrosion resistance. More specifically, it provides selective radiation shielding capabilities combined with antifouling and antistatic capabilities.

[0021] In several embodiments, the invention comprises a bi-layer or multilayer structure comprising a lightweight, flexible, transparent, substrate 10 (including, but not limited to, aerogels, pm-thin flexible ceramics, and siloxane -based space-qualified polymers) coated with a thin nickeliron alloy based ferromagnetic film 20 as an absorption media for medium to high energy charged particle radiation as well as electromagnetic interference (EMI) shielding. The magnetic film is grown through DC-magnctron sputtering of permalloy (Ni80Fc20) and co-sputtcring to alloy permalloy with dilute amounts of other metallic layers to further enhance corrosion resistance (i.e. Mo, Ru, W), and can be designed such that the magnetic alloy is impregnated into the bulk of the host material, as shown in the figure, leading to enhanced shielding effects, as well as patterned into desired geometries dependent on the application. Monitoring of magnetic properties is done non-locally through measurements of the Kerr or Faraday effects (shown in the figures), providing a means to monitor the film integrity and exposure in a non-destructive manner, even in corrosive environments. The substrate can be prepared using sol-gel processes and dried under supercritical conditions. In another form, the substrate can be prepared by means of crosslinking and curing at room temperature. An interfacial layer to enhance bonding may be included for some applications. Furthermore, full encapsulation of the entire entity will be considered for applications in aerospace.

[0022] Tire invention includes three distinct aspects: (1) shielding and sensing combined into one device; (2) usage of fully cured and crosslinked substrates to serve as tire platfonn for tire magnetically active layer; and (3) combining other sensing forms (such as temperature and shock) with magnetic sensing capabilities. The invention is the creation of a robust multifunctional platform that combines sensing thin films with porous, flexible, transparent, and inert 3-D materials, to provide a low-cost light-weight alternative to expensive, rigid, heavy, and single-use shielding technologies currently used.

[0023] The invention may be used to temporarily or permanently provide EM shielding through the encapsulation or enclosure at the desired location. The invention is removable, reusable, and non-invasive. It can be sized to the final shape and geometry desired by the end user. For example, a cube-shaped sensor can be placed adjacent to the electrical control units of electric and hybrid vehicles, to protect from interference.

[0024] The present invention offers an improvement to existing shielding technologies in several ways. First, the invention combines multiple types of sensing and shielding capabilities, with a focus on EM shielding. Other sensing needs can be added as desired. The proposed invention also is more cost-effective and versatile compared to existing techniques for shielding and sensing. The invention utilizes advanced state of the art coating techniques to deposit thin continuous films of magnetically active layers, on substrates that are intended for high performance under extreme conditions including flexible ceramics, aerogels, and siloxane-based polymers. The invention also may include an adhesion promoting layer 30 and technique to enhance stability of the multilayer.

[0025] In sum. the present invention combines light-weight materials with low-cost magnetic films that can be monitored for exposure and degradation in a non-destractive manner. Further, by allowing for the impregnation of the shielding material into a matrix, enhanced shielding effects from a much-rcduccd mass of materials allows for shielding with significantly less total mass, while maintaining corrosion resistance, essential for aerospace and EV applications. The invention further includes a novel technique for promoting adhesion and stability of the multilayer, and a novel technique for sensing, and shielding of EM radiation. The invention offers multi-sensing capabilities that can be customized based on the industry needs.

[0026] Supporting data and information for the above-described invention and various exemplary embodiments are described in detail in the attached Appendix materials, which are attached hereto and incorporated herein in their entireties (including all text and figures therein) by specific reference for all purposes.

[0027] Thus, it should be understood that the embodiments and examples described herein have been chosen and described in order to best illustrate the principles of the invention and its practical applications to thereby enable one of ordinary skill in the art to best utilize the invention in various embodiments and with various modifications as are suited for particular uses contemplated. Even though specific embodiments of this invention have been described, they are not to be taken as exhaustive. There are several variations that will be apparent to those skilled in the art.

[0028]

[0029]

[0030]

[0031]

[0032] Discussion & Conclusion

[0033] / -Results indicate that the morphology of Py-coated flexible YSZ ceramics change when the hetero structure undergoes a thermal cycling treatment from room temperature to -50°C to 350 ° C.

[0034] / -This change in morphology is only observed in 50 and 100 nm thick layers-not for the 10iim layer,

[0035] / - Results also indicate that the surface roughness of the layer decreases as the thickness of Py increases.

[0036] / -The coercivity increases significantly when temperature changes from 250 °C to 350 °C for Py thickness of 50 and 100 nm. For temperatures up to 250 °C, the coercivity is fairly constant for all thicknesses of Py.

[0037] / -The large increase in coercivity from 250 °C to 350 °C is attributed to increase in gran size. Results also show that coercivity first increases and then decreases. This effect may be due to change in grain size as well as domain wall of the Py-

[0038] / -Future work will include assessing the adhesion strength of the bilayer and response to mechanical stress and strain. Interplay between morphology, mechanical properties, and magnetic characteristics of permalloy coated aerogels

[0039] Introduction

[0040] Aerogels represent flexible, light weight platfonns with a variety of applications. Here we investigate the magnetization reversal of permalloy ( Ni80Fe20, Py) magnetic thin films over polyurea crosslinked silica aerogels (PC SA) and superelastic shape memory polymethane aerogels (SSMPA) to evaluate the potential of combining magnetic thin films on an aerogel platform. The impact of the substrate properties (surface roughness, continuity, and morphology) on tire magnetic coercivity (Hc) and saturation fields (Ms) of varying thicknesses of Py were investigated. The findings demonstrate that a thin, homogeneous coating forms for thicknesses of Py on PC SA above 10 nm, resulting in a standard evolution of coercivity vs. thickness for Py thin films, while clear differences are observed on SSMPA, including formation of in-plane anisotropy at 100 nm not present for lower thicknesses. We attribute these differences to the morphological differences of tire two aerogels.

[0041] 14 Methods

[0042] / - Two types of aerogels were prepared by sol-gel method [1.2].

[0043] / - These included polyurea crosslinked silica aerogels and superelastic shape memory polyurethane

[0044] / - Py films were deposited by means of magnetron sputtermg

[0045] / - Morphology characterization using Field Emission Scanning Electron Microscopy (FE-

[0046] SEM) and optical profilometry.

[0047] / - Magnetic characterization measured by Magneto optical Kerr effect (MOKE) Results

[0048] Morphology and uniformity of Py-coated aerogels

[0049]

[0050] Fig 3 : Optical Profilometry images of PCSA for 50nm (a) and 100nm Py (b): SSMPA for 50nm (c ) and 100nm (d) Py

[0051] Magnetization behavior of as-grown Pv films

[0052] Fig 4: Hysteresis of PCSA (a) and SSMPA (b) for increasing thicknesses of Py ;

[0053] Relationship between Coercivity and Thicknesses for PCSA. SSMPA and Si (c)

[0054] Conclusions and Further Work

[0055] The magnetic hysteresis of Py thin films on PCSA and SSMPA are evaluated and linked to the underlying aerogel microstructure. The scaling of the coercive field with film thicknesses above 10 nm is consistent with thin uniform growth, as commonly observed in magnetic thin films. However, the rougher SSMPA film results in deviations owing to the greatly increased surface roughness. Future work will investigate the effect of temperature on coercivity and stability of sputtered films. APS March Meeting 2024

[0056] Monday-Friday, March 4-8, 2024; Minneapolis & Virtual

[0057] Session S20: Advanced Characterization and Theory

[0058] 8:00 AM-10:36 AM, Thursday, March 7, 2024 Room: M101ABC

[0059] Sponsoring Unit: DCMP

[0060] Chair: Zac Ward

[0061] Abstract: S20.00004 : Effect of Argon Plasma- Induced Buckling on Coercivity of Permalloy Thin Films on PDMS

[0062] 8:36 AM-8:48 AM

[0063] Presenter:

[0064] Debendra Timsina

[0065] (Department of Physics and Material Science, University of Memphis, TN, 38152)

[0066] Authors:

[0067] Debendra Timsina

[0068] (Department of Physics and Material Science, University of Memphis, TN, 38152)

[0069] Kazi Zahirul Islam

[0070] (Department of Physics and Material Science, University of Memphis, TN, 38152)

[0071] Shawn D PollardfERRO

[0072] (Department of Physics and Material Science, University of Memphis, TN, 38152)

[0073] Firouzeh Sabri

[0074] (Department of Physics and Material Science, University of Memphis, TN, 38152)

[0075] The presence of stress / strain in thin films grown on compliant substrates such as polydimethylsiloxane (PDMS) can lead to a buckling phenomenon that is heavily influenced by the moduli and thickness of the film and the substrate. Thermally-induced stress / strain in the film is the most common cause of buckle formation. The periodicity, orientation, and overall buckling geometry can be controlled through other means and is the subject of this investigation. Here, the authors report on the effect of argon plasma treatment conditions on isotropic buckle formation in 10 and 50 nm thin permalloy (Py, Ni80Fe20) films, grown on PDMS substrates via sputter deposition. An increase in coercivity was detected when the substrates were functionalized, scaling with Ar plasma power. This work paves the way for the design and optimization of thin flexible electronic sensing devices and improved understanding of stress and strain impacts on magnetic properties.

[0076]

[0077] 10 nm Py results in complete blocking of UVB / UVC with partial Similar results for YSZ ceramics blocking of UVA, while still allowing optical transmission on PDMS.

[0078]

[0079]

[0080]

[0081] Abstract

[0082] Flexible Yttria- Stabilized Zirconia (YSZ) ceramic sheets were evaluated as potential platforms for flexible spintronic devices. These were coated with (Ni80Fe20. Py) films of increasing thicknesses ranging from 5nm-100nm by means of DC magnetron sputtering. The stability and the integrity of the Py film was evaluated as a function of temperature (T) cycles and induced stress / strain betw een 350°C and -50°C. Characterization techniques included FE-SEM. profilometry. and Kerr microscopy. Work presented will provide the framework for next generation remote sensing devices for extreme conditions.

[0083] Motivation: The flexible ceramic+Py heterostructure enables the use of ceramics for sensing applications that was not previously possible.

Claims

CLAIMSWhat is claimed is:

1. A system for enhanced electromagnetic shielding, comprising: a multi-layer shielding material comprising a flexible substrate with a first side and a second side; a ferromagnetic film disposed on at least the first side, the ferromagnetic film comprising a nickel-iron alloy.

2. The system of claim 1, wherein the flexible substrate is transparent.

3. The system of claim 1, wherein the flexible substrate comprises poly dimethy siloxane (PDMS).

4. The system of claim 1, wherein the flexible substrate comprises a polyurea crosslinked silica aerogels (PCSA).

5. The system of claim 1, wherein the flexible substrate comprises a polyurethane aerogel.

6. The system of claim 1, wherein the flexible substrate comprises a superelastic shape memory polyurethane aerogel.

7. The system of claim 1, wherein the flexible substrate comprises a Yttria-Stabilized Zirconia (YSZ) ceramic sheet.

8. The system of claim 1, wherein the ferromagnetic film comprises permalloy (Ni80Fe80, Py).

9. The system of claim 1, wherein the ferromagnetic film comprises patterned permalloy (Ni80Fe80Py).

10. The system of claim 1, wherein the ferromagnetic film is a sputtered permalloy.

11. The system of claim 5, wherein the ferromagnetic film has a thickness ranging from approximately 5nm to approximately lOOnm.

12. The system of claim 5, wherein the ferromagnetic film has a thickness ranging from approximately 50nm to approximately lOOnm.

13. The system of claim 5, wherein the ferromagnetic film has a thickness of 50nm.

14. The system of claim 5, wherein the ferromagnetic film has a thickness of 10nm.

15. The system of claim 1, wherein the multi-layer shielding material blocks transmission of UVB and UVC radiation, while allowing optical transmission on the flexible substrate.

16. The system of claim 1, wherein the multi-layer shielding material absorbs charged particle radiation.

17. The system of claim 1, wherein the multi-layer shielding material is an electromagnetic interference shielding material.

18. The system of claim 1, wherein the multi-layer shielding material blocks transmission of UVB and UVC radiation, while allowing optical transmission on the flexible substrate.

19. The system of claim 8, wherein the permalloy is alloyed with one or more additional metallic layers.

20. The system of claim 19, wherein the one or more additional metallic layers comprise one or more of Mo, Ru, or W.

21. The system of claim 8, wherein the permalloy impregnates, in whole or in part, the flexible substrate.

22. The system of claim 1, wherein the multi-layer shielding material further comprises a sensor.

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