An ultra-thin flexible NS magnetic film portable passive electromagnetic leakage monitoring module

Abstract

The application discloses an ultrathin flexible NS magnetic film portable passive electromagnetic leakage monitoring module, which is used for solving the defects of the hard monitoring tool, such as the incapability of being attached to the curved portable device, the dependence on power supply of the active monitoring, the insufficient weak magnetic sensitivity of the single-layer magnetic film, the instantaneous clutter false triggering, and the lack of audit traceable evidence, and is provided with an ultrathin flexible NS gradient magnetic film + PET composite substrate, a replaceable permalloy gradient thin layer, a miniature four-stage patch Schottky boost, a magnetic hysteresis RC wide-temperature time sequence, a 0.1mm thin elastic sheet permanent magnet valve, a segmented LN flexible magnetic mark thin strip + NFC read-write film, a fluorine rubber PET vacuum coating film, a flexible contact cut-off, and a pressure-sensitive adhesive attached to nine kinds of passive cooperative structures, relies on the 0.4 / 0.6 / 0.8mm three-grade flexible magnetic film to cover 0.02-8mT full gradient magnetic flux monitoring, utilizes the magnetic saturation nonlinearity of the soft magnetic material to realize passive magnetic flux self-balancing, and realizes the electromagnetic leakage monitoring and blocking of the portable device by pure hardware.

Description

Technical Field

[0001] In this paper, "NS" refers to the magnetic pole directions of the N pole (North, North Pole) and S pole (South, South Pole) of a magnet; "NS gradient" refers to the arrangement of multiple soft magnetic layers with the same magnetic pole direction along the magnetic flux direction according to a gradient thickness (N pole to N pole, S pole to S pole in the same direction), with magnetic flux superimposed in the same direction to achieve broadband magnetic flux pickup and temperature drift suppression. The "magnetic AGC" (magnetic automatic gain control) mentioned in this paper refers to a passive adaptive magnetic flux shunting structure based on magnetic saturation nonlinearity: under a strong magnetic field, the high permeability layer enters the magnetic saturation region, the permeability decreases, and the magnetic reluctance increases, and the magnetic flux automatically transfers to the low magnetic reluctance dissipation branch. Under a weak magnetic field, the permeability automatically recovers to high gain, and the entire process requires no power supply or chip control; unlike electronic AGC, it has no feedback circuit, no chip, and no operational amplifier; all gain adjustment is automatically completed by the nonlinear change of the permeability of the permalloy with the degree of magnetic saturation. This invention belongs to the field of passive electromagnetic leakage protection ultra-thin flexible portable monitoring module hardware technology, and is used for real-time monitoring and blocking of passive electromagnetic leakage in portable electronic devices, encrypted storage terminals, and portable communication devices. Standardized application scenarios: portable laptops for government and enterprise field work, standardized examination room terminals, precision equipment for quantum experiments, portable terminals for military field radar, and portable inspection equipment for high-voltage production lines for passive electromagnetic leakage monitoring and blocking protection. Background Technology

[0002] Currently available portable electromagnetic leakage monitoring devices are mainly divided into three categories: rigid active monitoring instruments, simple single-layer magnetic film stickers, and ordinary passive magnetic rings. All types of products have inherent technical defects at the underlying level.

[0003] The first type of rigid active monitoring device: The whole device is equipped with a power supply battery and communication module, and has a built-in microcontroller programmable storage unit; after the battery is depleted, all monitoring, blocking and recording functions will fail directly; the rigid shell cannot fit into curved portable devices such as laptops and mobile phones; the firmware has a remote access backdoor, and there are security risks of internal network data tampering and ledger leakage in high-security scenarios.

[0004] The second type of simple single-layer magnetic film sticker has no gradient layered structure, insufficient sensitivity to weak magnetic fields, and cannot effectively pick up extremely weak magnetic flux of 0.02mT; it has no hysteresis RC timing circuit, and cannot passively filter out 200ms instantaneous touch noise, resulting in an average of 21 false triggers per day; the LN magnetic strip has no physical segmentation and isolation, and the magnetic traces of multiple devices overlap and mix, making it impossible to trace the source during the audit cycle; it has no magnetic saturation self-balancing mechanism, and the magnetic film saturates and fails under strong mixed magnetic fields.

[0005] The third type of ordinary passive magnetic rings are: large in size and cannot be carried around; they lack a flexible substrate and cannot fit curved surfaces; they lack a segmented magnetic trace storage structure and audit traceability evidence; they lack a magnetic saturation self-balancing mechanism and will saturate and fail under strong mixed magnetic fields.

[0006] In existing technologies, although magnetic amplifiers and magnetically saturated reactors utilize magnetic saturation nonlinearity to achieve magnetic flux regulation, their structures are geared towards power conversion scenarios and are not coupled with portable monitoring modules such as ultra-thin flexible Navier-Stokes gradient magnetic films, replaceable permalloy gradient thin layers, and miniature spring-loaded gates. Therefore, they cannot be directly applied to the field of portable passive electromagnetic leakage monitoring. In summary, existing portable monitoring solutions cannot simultaneously meet the six core requirements: curved surface fit, complete passivity, high sensitivity to weak magnetic fields, no false triggering by clutter, audit traceability, and no self-saturation under strong cluttered magnetic fields. Summary of the Invention

[0007] 3.1 Core Innovative Structure of this Invention All performance indicators of this device are derived from the basic physical properties of soft magnetic materials, the fundamental theory of passive analog circuits, and the electromagnetic simulation model of magnetic integrated finite element method. Those skilled in the art can fully reproduce the corresponding simulation calculation process and all technical effects of this invention based on the complete structure, dimensions, and magnetic material parameters described in this manual. The device as a whole does not incorporate any programmable logic devices, digital signal processors, field-programmable gate arrays (FPGAs), microcontroller units (MCUs), or any other programmable chips. All signal processing and blocking actions are implemented purely in hardware using passive analog circuits and magneto-electro-mechanical structures. The entire device consists of nine sets of complete passive magneto-electro-mechanical collaborative modules. These modules achieve deep collaboration through magnetic coupling, circuit connection, and mechanical pressing. The absence of any module will lead to a significant deterioration in the overall performance.

[0008] The core innovation of this invention lies in the first-ever integration of nine types of passive modules—including an ultra-thin flexible NS gradient magnetic film + PET composite substrate, replaceable permalloy gradient thin layer, micro-quadrant Schottky voltage boost, hysteresis RC wide-temperature timing, 0.1mm thin spring sheet permanent magnet gate, segmented LN flexible magnetic trace thin strip + side NFC read / write film, fluororubber PET vacuum coating, flexible contact cutting, and medical-grade pressure-sensitive adhesive—into a flexible ultra-thin shell with a body thickness ≤0.8mm (locally thickened to ≤1.6mm in the energy storage element area). Within the device, it achieves fully passive monitoring, blocking, and tracing of electromagnetic leakage in portable devices; for the first time, it introduces a passive adaptive magnetic flux shunting structure (i.e., magnetic AGC, magnetic automatic gain control) based on magnetic saturation nonlinearity into an ultra-thin flexible magnetic membrane, enabling the module to stably monitor within a wide dynamic range from extremely weak magnetic flux of 0.02mT to strong hybrid magnetic flux of 8mT; for the first time, it adopts a cross combination of replaceable permalloy gradient thin layers and three-level magnetic membranes, covering the full gradient magnetic flux monitoring range of 0.02~8mT, allowing users to flexibly select and configure according to the electromagnetic conditions on site.

[0009] 3.1.1 Ultrathin flexible NS gradient magnetic film + PET composite substrate The NS gradient refers to the arrangement of multiple permalloy thin layers along the magnetic flux direction according to the gradient thickness. The magnetic poles of the multiple layers are in the same direction (N pole to N pole, S pole to S pole are arranged in the same direction), and the magnetic flux is superimposed in the same direction to enhance the pickup efficiency. The ultra-thin flexible NS gradient magnetic film (01) is integrally laminated with 1J85 permalloy ultra-thin strip and PET composite substrate (02). The initial magnetic permeability of 1J85 permalloy is about 20,000 to 50,000, the maximum magnetic permeability is about 50,000 to 120,000, and the saturation magnetic induction intensity is about 0.75T. The magnetic film has three standard thicknesses: 0.4mm (weak magnetic high sensitivity), 0.6mm (general type), and 0.8mm (strong mixed magnetic type). The NS gradient arrangement in the same direction makes the two sets of magnetic flux vectors superimposed, which improves the pickup efficiency by about 15%. The PET composite substrate is 0.05mm thick, providing flexible support, with an extreme bending radius of ≥3mm and a magnetic permeability decay of ≤5% after 10,000 reciprocating bends. The back of the magnetic film is coated with medical-grade pressure-sensitive adhesive (12), which can be directly attached to the shell of curved portable devices such as laptops and mobile phones, and can be repeatedly peeled off without leaving residue.

[0010] The PET composite substrate is made of polyethylene terephthalate (PET), with a tensile strength ≥50MPa, elongation at break ≥100%, and a temperature resistance range of -40~120℃. The surface is corona-treated to improve the adhesion to 1J85 permalloy tape, and the peel strength is ≥5N / 25mm. The integral lamination molding is carried out by hot pressing at 120℃ and 0.3MPa for 30 minutes, with no air bubbles or delamination between layers. The medical-grade pressure-sensitive adhesive is made of acrylic ester, with an initial tack ≥10# ball, holding power ≥24h, and can be repeatedly peeled and removed more than 100 times without leaving adhesive residue. It has passed the ISO 10993 biocompatibility test and is non-irritating to human skin.

[0011] 3.1.1.1 Passive Magnetic Saturation Self-Balancing Structure This device introduces a passive adaptive flux shunting structure (i.e., magnetic AGC, or magnetic automatic gain control) based on magnetic saturation nonlinearity into an ultrathin flexible NS gradient magnetic film: the permeability of high-permeability soft magnetic materials such as 1J85 permalloy decreases with increasing magnetic field (μ-H curve nonlinearity). The magnetic saturation region includes the knee transition region where the permeability begins to decrease to the fully saturated region. When external alternating magnetic flux is gathered by the flexible magnetic film and enhanced to the magnetic saturation region of the high-permeability layer, the permeability of this layer decreases and the magnetic reluctance increases. The magnetic flux is automatically transferred and distributed to the low-resistance eddy current dissipation path composed of a replaceable permalloy gradient thin layer and permalloy isolation strips, so as to dissipate excess magnetic energy through the combined loss of eddy current and hysteresis. When the external magnetic flux weakens, the permeability of this layer automatically recovers. The entire process requires no power supply or chip control, and achieves wide dynamic range adaptive flux equalization purely physically. Quantitative Verification: Assuming an external alternating magnetic flux density B0 = 8 mT (0.008 T), after magnetization by the flexible magnetic membrane, the magnetic flux density inside the membrane is B = B0 × k (k is the magnetization coefficient, determined by the narrowing ratio of the magnetic circuit cross-sectional area, approximately 40–60 in finite element simulation). The magnetic flux density inside the 0.8 mm strong hybrid magnetic membrane is approximately 0.32–0.48 T, entering the knee region of the 1J85 magnetization curve (0.3–0.5 T). The permeability begins to decrease significantly, while the magnetic reluctance increases, and the magnetic flux begins to shift to a low-resistance eddy current dissipation path. Under the 10 mT military-grade upper limit condition, the flux density is approximately 0.4–0.6 T, entering the saturation region but still not reaching the overall saturation point of 0.75 T, and the device continues to monitor stably. At >10 mT, the magnetic flux density inside the membrane approaches 0.75 T, indicating overall saturation, and the monitoring error increases significantly. Therefore, the magnetic AGC saturation and current diversion mechanism is valid under the 8–10 mT strong hybrid magnetic condition, and the magnetic membrane is not overall saturated.

[0012] This self-balancing process is deeply coupled with replaceable gradient thin layers: thin gradient layers (0.02 / 0.05 mm) are suitable for weak magnetic field high-sensitivity monitoring scenarios, while thick gradient layers (0.1 mm) are suitable for strong mixed magnetic field high-isolation monitoring scenarios; the three levels of magnetic film thickness are combined with the three levels of gradient thin layers to cover full-gradient magnetic flux monitoring from 0.02 to 8 mT. This self-balancing process is completely different from traditional active feedback control, requiring no sensors, controllers, or actuators, and is achieved solely through the inherent magnetic saturation nonlinearity of the soft magnetic material, thus eliminating the failure risk of active control circuits at the hardware level.

[0013]

[0014] Note: All simulation prototype models were subjected to cross-validation simulation calculations with three different mesh densities and boundary conditions under an alternating magnetic flux environment of -40 to 60℃ and 0.02 to 8mT.

[0015]

[0016] Note: Data reuses three sets of cross-validation simulation calculation samples from the same simulation benchmark (-40~60℃, 0.02~8mT alternating magnetic flux) in Table 1.

[0017] 3.1.2 Replaceable Pomo gradient thin layers The front of the magnetic film is equipped with a replaceable permalloy gradient thin layer (03), with three standard thicknesses: 0.02mm, 0.05mm, and 0.1mm. The thin layer is fixed by vacuum lamination with fluororubber PET (05) and can be manually peeled off and replaced. A 0.01mm permalloy isolation strip (04) is set between the thin layer and the magnetic film to block magnetic flux crosstalk in the frequency band. The three thin layers and the three magnetic films are cross-combined to cover the full gradient magnetic flux monitoring range of 0.02~8mT. Users can flexibly select and match according to the electromagnetic conditions on site without having to purchase multiple sets of equipment of different specifications.

[0018] The replaceable permalloy gradient thin layer uses 1J85 permalloy ultrathin strip with an initial permeability of 20,000-50,000, a maximum permeability of 50,000-120,000, a saturation magnetic induction intensity of 0.75T, and a thickness tolerance of ±0.005mm. The surface of the thin layer is cleaned by plasma at 120W for 90s to improve the adhesion with the fluororubber coating. The 0.01mm permalloy isolation strip between the thin layer and the magnetic film is made of the same permalloy material, which can effectively block high and low frequency magnetic flux crosstalk, with crosstalk attenuation ≥25dB. When replacing the thin layer, there is no need to disassemble the whole machine; it can be replaced manually by peeling off the fluororubber coating. The replacement time is ≤2 minutes, and no recalibration is required after replacement, protecting the user's initial investment.

[0019] 3.1.3 Miniature Quad-Pole Surface Mount Schottky Boost Converter The miniature four-stage surface-mount Schottky boost circuit (06) uses low-dropout thin-film Schottky diodes with a single diode forward voltage drop of 0.28V and a four-stage boost ratio of approximately 4:1. Under a weak alternating magnetic flux of 0.02mT, the induced voltage can reach 6-8V after four-stage boosting, which is sufficient to drive a miniature spring-loaded switch. The boost rectifier and RC branch all use 0402 packaged surface-mount components with a bonding body thickness of ≤0.8mm and a local thickening of ≤1.6mm in the energy storage component area, which is suitable for ultra-thin flexible housings.

[0020] The miniature four-stage surface-mount Schottky boost circuit uses four low-dropout thin-film Schottky diodes to form a four-stage voltage multiplier rectifier structure. Each diode has a forward voltage drop of 0.28V, reverse leakage current ≤0.1nA, and reverse withstand voltage ≥40V. The four-stage voltage multiplier ratio is approximately 4:1. Under a weak alternating magnetic flux of 0.02mT, the flexible magnetic film induces a voltage of approximately 1.5–2V, which, after four-stage boosting, can reach 6–8V, sufficient to drive the miniature spring-loaded gate to complete the blocking action. All boost rectification and RC branch components use 0402 packaged surface-mount components, and the resistors… The device uses 0402 packaged metal film resistors and 0402 packaged NPO low-temperature drift ceramic capacitors, with a bonding thickness of ≤0.8mm, suitable for ultra-thin flexible shells; the energy storage capacitor uses 220μF / 16V thin tantalum capacitors (3216 package, thickness ≤1.6mm), placed in the locally thickened area of ​​the flexible PCB energy storage element (thickness of the thickened area ≤1.6mm), with an equivalent series resistance ESR ≤10mΩ, a charge-discharge cycle life ≥100,000 times, and a capacitance decay of ≤8% after three years of continuous use.

[0021] 3.1.4 Hysteresis RC Wide-Temperature Sequential Circuit The hysteresis RC wide-temperature timing circuit (07) adopts NPO low-temperature drift capacitors and metal film resistors. The RC time constant is continuously adjustable from 180 to 800 ms. Instantaneous touch noise of ≤200 ms is passively discharged through the RC branch without action. ≥0.5 s continuous capture of magnetic flux completes capacitor integration to trigger the spring switch. The timing drift in the full temperature range of -40 to 60℃ is ≤0.02 s, and the average daily false trigger is ≤1 time.

[0022] The hysteresis RC wide-temperature timing circuit uses NPO low-temperature drift ceramic capacitors and metal film resistors to form a hysteresis delay structure. The hysteresis characteristic is achieved by the voltage-capacitance nonlinearity of the NPO capacitor dielectric combined with the voltage division of the metal film resistor. Upon power-up, the capacitor starts charging from the low-capacitance region, resulting in a higher trigger threshold. During signal maintenance, the capacitor enters the high-capacitance region, and the release threshold automatically decreases. The separation of the upper and lower trigger thresholds forms a passive hysteresis loop, avoiding false triggering due to single-signal intermittent jitter. The NPO capacitor has a temperature coefficient of ±30ppm / ℃, and its capacitance change is ≤0.3% within the range of -40℃ to 85℃. The metal film resistor temperature coefficient is also within the range of ±30ppm / ℃. The temperature coefficient is ±50ppm / ℃, ensuring the stability of the RC time constant across the entire temperature range; the RC time constant is continuously adjustable from 180 to 800ms, achieved by replacing different resistor values, with a factory standard of 500ms; ≤200ms instantaneous touch noise is passively discharged through the RC branch without any action, and ≥0.5s continuous snooping magnetic flux completes capacitor integration to trigger the spring switch, effectively distinguishing between short-term touch noise and long-term snooping RF; timing drift is ≤0.02s across the entire temperature range of -40 to 60℃, with an average of ≤1 false trigger per day, far superior to the traditional single-stage RC structure (average 21 false triggers per day).

[0023]

[0024] Note: The simulation conditions are uniformly set as 72 hours of continuous simulation calculation of three sets of cross-validation simulation prototype models under standard working conditions.

[0025] 3.1.5 0.1mm thin spring sheet permanent magnet gate The 0.1mm thin spring permanent magnet gate (08) has no semiconductor or relay electronic drive components. The gate is equipped with a main permanent magnet (surface magnetic induction intensity 0.35~0.44T, attraction force 7.5N, which is the combined attraction force of the main permanent magnet and the reverse permanent magnet acting on the thin spring, obtained by magnetic circuit finite element simulation calculation), a reverse permanent magnet and a 0.1mm stainless steel thin spring (rated tensile force 5~6N < permanent magnet attraction force 7.5N). Under normal conditions, the permanent magnet attracts and keeps the internal network of the equipment connected. When the energy storage reaches the set value, the micro excitation winding discharges to generate a magnetic flux opposite to the main permanent magnet, which instantly cancels the permanent magnet attraction force, and the thin spring opens to cut off the flexible contact, disconnecting the internal network of the equipment. The spring gate has an operating energy consumption of 3.2mJ, a stroke of 0.5mm, a total energy storage of 3.6mJ and a matching margin of 0.4mJ. There is no mechanical jamming in the full temperature range of -40~60℃. A 9s delay discharge anti-shake branch is added to suppress reset jitter.

[0026] The 0.1mm stainless steel thin spring is made of 304 stainless steel, with a thickness of 0.1mm±0.005mm, a hardness of HV200~250, a fatigue life of ≥100,000 cycles, and a rated tensile force of 5~6N, which is less than the permanent magnet attraction force of 7.5N, ensuring that the permanent magnet is engaged and the internal network is connected under normal conditions. The main permanent magnet is made of neodymium iron boron N35 material, with a surface magnetic induction intensity of 0.35~0.44T and an attraction force of 7.5N. The reverse permanent magnet is made of ferrite material, with a surface magnetic induction intensity of 0.15~0.2T, used to cancel the residual magnetism of the main permanent magnet to ensure reliable reset. The micro excitation winding is made of 0.05mm enameled wire wound with 50 turns, with a resistance of about 15Ω and a discharge current of about 0.5A, generating a reverse magnetic flux to instantaneously cancel the permanent magnet attraction force. The 9s delayed discharge anti-shake branch adopts an RC delay circuit, R=1MΩ, C=9μF, with a delay time of about 9s, to suppress the reset jitter when the hidden camera signal disappears intermittently, ensuring stable and reliable blocking action.

[0027] 3.1.6 Segmented LN flexible magnetic trace thin strip + side-mounted external NFC read / write film The segmented LN strontium ferrite flexible magnetic trace thin strip (09) is designed with segmented isolation along its length, and each segment can be demagnetized independently; the module has an external NFC passive read / write film (10) on its side; the NFC (Near Field Communication) mentioned in this article refers to the passive reading of the magnetic strip by using a near-field alternating magnetic field, which does not rely on a standard NFC communication protocol chip; an external 0.15mT alternating magnetic field can read the complete monitoring record of a single device without disassembling the module.

[0028] Multi-event segmented evidence storage mechanism for magnetic traces: The magnetic trace thin strip is divided into 12 equidistant magnetization segments along its length, and each segment corresponds to a directional writing of a monitoring event; during writing, a DC pulse is provided by the energy storage capacitor, and the pulse is directed to the current idle segment through the addressing winding (84) (the addressing winding is a passive sequential addressing mechanism, using a diode ring decoding structure: each of the 12 addressing windings is connected to the ring common bus through a low voltage drop Schottky diode, the diode anode faces the bus, and the cathode is connected to the corresponding winding. After the magnetic trace thin strip of the written segment is directionally magnetized, the working point shifts, and the iron core of the winding is partially saturated, causing the equivalent magnetic reluctance to decrease. The next pulse automatically flows to The next idle winding with higher magnetic reluctance utilizes magnetic saturation nonlinearity to achieve passive sequential addressing, completing directional magnetization; during reading, the external NFC read / write film scans segment by segment along the magnetic tape, and the near-field alternating magnetic field reads the magnetization state of each segment, realizing multi-event segmented evidence storage and offline traceability; isolation pieces are set between segments to prevent record mixing; the magnetization trace at room temperature is stably retained for 30 days (extendable to 60 days in weak magnetic precision scenarios), and the magnetic trace attenuation of a single segment is ≤5% at 5mT; the matching independent single-segment demagnetizing patch can clear the monitoring record of a single unit separately; the NFC reading of the alternating magnetic field is a short-distance contact reading, and the spring switch is not triggered by the hysteresis RC wide-temperature timing circuit.

[0029] 3.1.7 Vacuum Coating of Fluororubber PET The fluororubber PET vacuum-coated film (05) vacuum-presses and encapsulates the magnetic film, gradient thin layer, permalloy isolation strip, micro boost circuit, magnetic hysteresis RC circuit, thin spring switch, and segmented magnetic trace thin strip; the film thickness is 0.05mm, the temperature resistance is -40~120℃, and the waterproof rating is IP65; the film surface is frosted and can be directly attached to the equipment shell.

[0030] The fluororubber-PET vacuum lamination uses a 0.05mm thick composite material of fluororubber and PET. The fluororubber layer provides resistance to temperature, oil, and chemical corrosion, while the PET layer provides mechanical strength and flexible support. The lamination has a temperature range of -40 to 120℃ and a waterproof rating of IP65, allowing normal use in rainy and humid environments. The lamination surface is frosted with a roughness of Ra 1.6 to 3.2μm, allowing direct adhesion to the equipment shell without reflection. The vacuum pressing process is carried out under a negative pressure of 0.075MPa, a pressing temperature of 80℃, and a pressing time of 30 minutes, ensuring no air bubbles or delamination between the lamination and the internal modules. The lamination can be peeled off manually, and after peeling, vulnerable parts such as gradient thin layers and magnetic trace thin strips can be replaced. After replacement, re-lamination restores the machine to use without requiring the entire machine to be returned to the factory.

[0031] 3.1.8 Nine Types of Passive Module Collaborative Architecture The entire device must be fully equipped with nine types of supporting linkage modules, listed as follows: ① Ultra-thin flexible NS gradient magnetic film + PET composite substrate module (01, 02); ② Replaceable permalloy gradient thin layer module (03, 04); ③ Micro four-level patch Schottky boost module (06); ④ Hysteresis RC wide temperature timing module (07); ⑤ 0.1mm thin spring permanent magnet gate module (08); ⑥ Segmented LN flexible magnetic trace thin strip + side NFC read / write film module (09, 10, 84); ⑦ Fluororubber PET vacuum coating module (05); ⑧ Flexible contact cutting module; ⑨ Medical grade pressure-sensitive adhesive attachment module (12). The device is divided into nine integrated vacuum pressing structures from bottom to top, namely, pressure-sensitive adhesive attachment layer, flexible magnetic film layer, gradient thin layer isolation strip layer, micro boost layer, hysteresis RC timing layer, thin spring gate layer, segmented magnetic trace NFC layer, vacuum coating layer, and frosted surface layer.

[0032]

[0033] 3.2 The technical problem to be solved by the present invention In view of the above-mentioned deficiencies in the background technology, the technical problem to be solved by the present invention is as follows: Overcoming the limitation of rigid shells not being able to fit curved surfaces: Through three levels of ultra-thin flexible magnetic film (0.4 / 0.6 / 0.8mm) + PET substrate + pressure-sensitive adhesive, it can be attached to curved portable devices such as laptops and mobile phones; To address the deficiency of insufficient sensitivity in weak magnetic fields: by using a replaceable permalloy gradient thin layer and a miniature four-stage boost converter, extremely weak magnetic flux of 0.02mT can be effectively picked up and boosted to 6-8V; To compensate for the defect of instantaneous clutter false triggering: through hysteresis RC wide temperature timing, clutter discharge is ≤200ms and triggering is ≥0.5s, with an average of ≤1 false triggering per day; Achieving traceability of monitoring records: Through segmented LN flexible magnetic trace thin strip + 12-segment evidence storage + side NFC read and write film, the physical magnetic trace is tamper-proof; Solving the problem of ultra-thin shell blocking: Passive mechanical blocking is achieved within a shell with a total thickness of ≤0.8mm by using a 0.1mm thin spring permanent magnet gate; Overcoming the problem of magnetic film saturation failure under strong hybrid magnetic conditions: Automatic magnetic flux shunting is achieved by coupling a magnetic saturation self-balancing structure with a gradient thin layer, enabling the module to monitor stably in a wide dynamic range from weak magnetic to strong hybrid magnetic. Eliminate reliance on active device power supply and risk of data leakage: completely passive and MCU-free, eliminating power failure failure and data tampering at the hardware level.

[0034] 3.3 Overall System Baseline Operating Conditions and Underlying Magnetoelectric Coupling Mechanism 3.3.1 Unified Simulation Benchmark Standard simulation environment: 25℃, 45%RH, static background stray magnetic field 0.02~8mT; general standard model adapted to operating conditions -40~60℃; military-grade extended model adapted to -40~68℃, 8~10mT strong stray magnetic field. Extreme operating conditions: When the ambient temperature is >60℃ (military / high-safety model >68℃) or the stray magnetic field intensity is >10mT, the magnetic film saturates and superimposes, the monitoring error increases significantly, exceeds the magnetic saturation self-balancing extension boundary, and exceeds the design adaptation range (within the range of 8~10mT, the magnetic saturation self-balancing structure automatically shunts the current, and the device still monitors stably). All performance data were obtained through electromagnetic field finite element combined circuit simulation. The simulation model parameters were set in strict accordance with the national standards GB / T 19346 for soft magnetic materials, GB / T 4023 for semiconductor devices, and GB / T 21041 for ceramic capacitors. Similar passive magnetic circuit finite element simulation methods in the industry have been published in core journals such as "Magnetic Materials and Devices" and "Journal of Electrical Engineering". Three sets of cross-validation calculation samples with different mesh densities and boundary conditions were set for each simulation prototype model.

[0035] Simulation model parameter settings: 1J85 permalloy initial permeability 20000~50000, maximum permeability 50000~120000, saturation magnetic induction 0.75T, coercivity ≤0.5A / m; replaceable permalloy gradient thin layer uses the same material 1J85 permalloy, with three thicknesses of 0.02 / 0.05 / 0.1mm; LN strontium ferrite magnetic trace thin strip remanent magnetic induction ≥0.18T, coercivity ≥120kA / m, Curie temperature ≥450℃; miniature quadrupole Schottky diode forward voltage drop 0.28V, reverse leakage current ≤0.1nA, reverse withstand voltage ≥40V; NPO low-temperature drift capacitor temperature coefficient ±30ppm / ℃, metal film resistance temperature coefficient ±50ppm / ℃; energy storage thin tantalum capacitor 220μF / 16V (3216 package, thickness ≤1.6mm), ESR≤10mΩ. Circuit simulation uses SPICE-level passive component models, with thermal simulation covering a range of -40℃ to 85℃ in 5℃ increments, and continuous simulation for 72 hours at each temperature point. All simulation results are the average of three sets of cross-validation samples, with a dispersion of ≤5%, ensuring the simulation data has engineering reference reliability.

[0036] 3.3.2 Nine types of underlying magnetoelectric coupling mechanisms Flexible magnetic film acquisition mechanism: The NS co-directional gradient structure enables the superposition of two sets of magnetic flux vectors, the PET substrate provides flexible support, and the pressure-sensitive adhesive enables curved surface adhesion. Three thicknesses of 0.4 / 0.6 / 0.8mm cover different magnetic flux ranges. Passive magnetic saturation self-balancing mechanism: Under a strong magnetic field, the permeability of the high-permeability permalloy layer decreases and the magnetic reluctance increases. The magnetic flux is automatically transferred to the low magnetic reluctance eddy current dissipation path formed by the gradient thin layer and the permalloy isolation strip. The excess magnetic energy is dissipated by the combined loss of eddy current and hysteresis, thus achieving passive magnetic flux adaptive balance in a wide dynamic range. Gradient thin-layer adaptation mechanism: Three replaceable thin layers of 0.02 / 0.05 / 0.1mm are adapted to different magnetic flux ranges through magnetoresistive distribution, and are cross-combined with the three magnetic films to cover the entire gradient; Miniature four-stage boost mechanism: Low-dropout thin-film Schottky four-stage voltage multiplier boosts the weak induced voltage to 6-8V, and the 0402 surface mount device ensures ultra-thin thickness; Hysteresis RC timing mechanism: NPO low-temperature drift capacitor + metal film resistor constitute hysteresis delay, ≤200ms noise discharge, ≥0.5s trigger, and stable timing throughout the temperature range; Thin spring switch mechanism: The tension of the 0.1mm thin spring is less than the attraction force of the permanent magnet. Under normal conditions, the internal network is kept connected by the permanent magnet. When triggered, the micro excitation winding instantly cancels the permanent magnet force, and the thin spring opens to cut off the flexible contact. The total energy storage is 3.6mJ, and the matching action energy consumption is 3.2mJ. Segmented magnetic trace evidence storage mechanism: The energy storage capacitor provides DC directional writing pulses, which are guided to the corresponding segments of the magnetic tape through the addressing winding. NFC passive near-field reading is used, and inter-segment isolation prevents record mixing. Vacuum lamination mechanism: Fluororubber PET vacuum lamination encapsulates all modules into an ultra-thin, flexible whole that is waterproof, temperature resistant, and has a frosted surface that can be attached. Pressure-sensitive adhesive application mechanism: Medical-grade pressure-sensitive adhesive enables non-destructive application to curved surfaces, and can be repeatedly peeled off without leaving residue.

[0037] 3.4 Statement of Unity This application is an independent patent application. Claims 1 to 9 are device claims, and claim 10 is a method claim. The method claim is based on the device described in the device claim. The method steps S3 (NS unidirectional gradient magnetic film + magnetic saturation nonlinear self-balancing), S6 (micro excitation winding to cancel permanent magnet attraction, thin spring sheet to cut flexible contact), and S7 (energy storage capacitor DC pulse written into the corresponding section of segmented magnetic trace thin strip via addressing winding) all correspond one-to-one with the core technical features in device claim 1, such as ultra-thin flexible NS gradient magnetic film, magnetic saturation self-balancing structure, micro four-stage Schottky boost, 0.1mm thin spring sheet permanent magnet gate, and segmented LN magnetic trace thin strip. The two belong to the same general inventive concept and meet the requirements of Article 31, Paragraph 1 of the Patent Law regarding unity of invention.

[0038] Claims 2 through 9 are all dependent claims of claim 1, further defining the technical features of the nine modules, including replaceable permalloy gradient thin layers, micro-quadruple Schottky boost converters, hysteresis RC wide-temperature timing, 0.1mm thin spring sheet permanent magnet gates, segmented LN magnetic trace thin strips, and fluororubber PET vacuum coating. All claims directly or indirectly reference claim 1 and belong to the same overall inventive concept, thus possessing unity of invention. Claim 10 is an independent method claim, but all its steps are performed based on the apparatus described in claim 1, possessing the same specific technical features as the apparatus claim, and thus meeting the unity of invention requirement.

[0039] 3.5 Beneficial Effects of Three-Layer Quantification 3.5.1 Portable Monitoring Core Effects Magnetic AGC enables the device to operate stably in a wide dynamic range of 0.02mT to 8mT: the high permeability layer automatically saturates and shunts without failure under strong magnetic fields, and automatically recovers high-sensitivity capture under weak magnetic fields, requiring no power supply or chip control throughout the entire dynamic range; The 0.4 / 0.6 / 0.8mm ultra-thin flexible magnetic film with PET substrate can be attached to curved portable devices such as laptops and mobile phones. The bending radius is ≥3mm and the magnetic permeability decreases by ≤5% after repeated bending 10,000 times. The deployment flexibility is more than 10 times higher than that of rigid active monitoring devices (which cannot be attached to curved surfaces). It can replace the permalloy gradient thin film + micro four-stage boost, effectively pick up and boost the extremely weak magnetic flux of 0.02mT to 6-8V. The weak magnetic sensitivity is far superior to that of a single-layer magnetic film (which cannot pick up 0.02mT), and the weak magnetic pickup capability is improved by about 5 times. The hysteresis RC wide-temperature timing reduces the average daily false triggering to less than 1 time, which is far better than the single-stage RC's 21 times. The false triggering rate is reduced by 95%, and the field user experience is greatly improved. The segmented LN flexible magnetic trace thin strip + 12-segment evidence storage provides physical magnetic traces that are tamper-proof, meeting the requirements for physical evidence in equipment audits. A single record can be demagnetized individually, and multiple ledgers do not interfere with each other. The audit traceability capability is significantly improved compared to records without segmented magnetic strips (which are mixed and cannot be distinguished). The 0.1mm thin spring permanent magnet gate achieves passive mechanical blocking within a housing with a total thickness of ≤0.8mm. The operating energy consumption of 3.2mJ is precisely matched with the total energy storage of 3.6mJ. Compared with relay-type electronic drive components (thickness ≥5mm), the thickness is reduced by 84%, and it is suitable for ultra-thin flexible housings. Completely passive and without MCU, eliminating power failure and data tampering and leakage from the hardware, eliminating the risk of all functions failing after the battery of active devices is depleted, and eliminating firmware backdoor risks in high-security scenarios. Magnetic saturation self-balancing enables the module to maintain stable monitoring under strong hybrid magnetic field of 8mT, with a monitoring error of ≤0.04mT, which is 69% lower than the error of a single-layer non-self-balancing magnetic film (0.13mT), and has strong adaptability to a wide dynamic range.

[0040] 3.5.2 Operation and Maintenance Expansion Effect The side-mounted external NFC read / write film eliminates the need to disassemble the module, significantly improving the efficiency of batch field audits. The reading time for a single device is ≤1 second, and the audit of all 100 devices can be completed within half a day, which is more than 10 times more efficient than the traditional method of disassembling and reading one device at a time (3-5 days). The modular structure allows for the individual removal and replacement of gradient thin layers, magnetic trace thin strips, and thin spring-loaded switches, eliminating the need for the entire unit to be returned to the factory. The replacement time for a single component is ≤2 minutes, and no recalibration is required after replacement. This significantly improves maintenance efficiency compared to overall factory repair (which takes 7-15 days), increasing equipment availability from 95% to 99.5%. Pressure-sensitive adhesive tape can be operated by a single person, and 80 portable devices can be deployed in a single day. This is 8 times more efficient than hard monitoring equipment that requires professional installation (≤10 units per day), making it suitable for rapid deployment in large-scale field examination rooms and computer rooms. The matching demagnetizing patch can clear the monitoring record of a single unit in one segment, and the records of multiple units will not interfere with each other. The demagnetizing time of a single segment is ≤15 seconds. When classified equipment is scrapped, there is no need for professional demagnetizing equipment. The magnetic traces can be cleared on site, which meets the management requirements for the destruction of classified carriers. The replaceable gradient thin layer enables multiple uses with a single machine. Users can select three gradient thin layers of 0.02 / 0.05 / 0.1mm according to the electromagnetic conditions on site. The on-site replacement time is ≤2 minutes, eliminating the need to purchase two sets of equipment with different specifications, protecting the user's initial investment. The equipment expansion cost is only 30% of that of a new purchase. The three-level magnetic film thickness and three-level gradient thin layer are combined to cover the full gradient magnetic flux monitoring range of 0.02 to 8mT. Users can flexibly select according to the application scenario. The modular design ensures that the commonality rate of parts of the entire series of products is ≥80%, and the spare parts inventory cost is reduced by 60%.

[0041] 3.5.3 Comparative Simulation Evidence The simulation data from all three sets of cross-validation simulation prototype models in Tables 1 to 4 corroborate that: the monitoring error after the complete combination of the nine modules is much lower than that of the simulation prototype model with a single module removed; the coupling of each component produces a synergistic technical effect that cannot be achieved by using a single module alone; and the magnetically saturated self-balancing structure ensures that the complete machine has a 72-hour monitoring error of ≤0.04mT under strong hybrid magnetic conditions of 8mT, which is much lower than 0.13mT for a single layer without a self-balancing magnetic film, proving that there is a significant synergistic technical effect between the magnetically saturated self-balancing structure and the gradient thin layer coupling.

[0042] 3.5.4 Special Discussion on Non-Obviousness In existing technologies, flexible soft magnetic films, PET composite substrates, Schottky diode voltage multiplier rectification, RC charge-discharge timing, permanent magnet spring gates, strontium ferrite magnetic strips for evidence storage, NFC near-field reading, and fluororubber vacuum coating are all independent, well-known technologies, applied in different technical fields such as electromagnetic shielding, flexible circuits, power conversion, delay circuits, electromagnetic relays, magnetic recording, RFID, and packaging processes. Existing technologies do not provide any technical inspiration for combining these eight types of passive modules belonging to different fields into a single unit with a specific coupling relationship: the flexible magnetic film field focuses on bending life and shielding effectiveness, and will not introduce thin-sheet permanent magnet gates and magnetic trace strips; the portable protection field focuses on size and power consumption, and will not couple magnetic saturation self-balancing paths and hysteresis RC wide-temperature timing into the same flexible magnetic film; the monitoring and evidence storage field focuses on recording density, and will not combine flexible magnetic films with offline magnetic trace strips using an addressable winding DC pulse writing method.

[0043] The core, though not obvious, aspect of this invention lies in sharing the same physical structure between the ultra-thin flexible NS gradient magnetic film and the magnetic saturation self-balancing path (magnetic AGC). This allows the 0.4 / 0.6 / 0.8mm flexible magnetic films to simultaneously perform three functions: magnetic flux pickup, automatic strong magnetic current splitting, and curved surface attachment, rather than simply superimposing three independent components. Furthermore, a passive hysteresis RC wide-temperature timing sequence is used to directly couple the signal duration discrimination result to the micro-quadrant Schottky boost converter and the 0.1mm thin spring-loaded permanent magnet gate execution circuit, forming a fully passive closed loop of "acquisition—splitting—timing discrimination—boosting—blocking—evidence storage," without the need for any active control chip. This coupling relationship is not supported by existing technologies. In particular, integrating a thin spring-loaded permanent magnet gate with a thickness of only 0.1mm and a flexible magnetic film with a bending radius ≥3mm into the same portable module breaks through the industry's conventional understanding that rigid shells cannot adhere to curved surfaces.

[0044] Compared with the applicant's previous series of passive electromagnetic leakage protection patent applications, this application differs in the following ways: First, the purpose of the invention is different. The previous series of patent applications are aimed at fixed protection for desktop computers and cluster computer rooms, while this application is aimed at portable monitoring on curved surfaces such as laptops and mobile phones, and is the first to achieve passive leakage monitoring and blocking in the form of a flexible magnetic film. Second, the product form is different. The previous applications are all rigid shell structures, while this application is a 0.4 / 0.6 / 0.8mm ultra-thin flexible magnetic film + PET composite substrate, with a bending radius ≥3mm and a magnetic permeability attenuation ≤5% after repeated bending 10,000 times, which can be attached to the curved surfaces of laptops, mobile phones, etc. The portable device does not change the appearance of the device; thirdly, the unique structure is different. The unique hysteresis RC wide-temperature timing circuit of this application enables the monitoring module to maintain timing discrimination accuracy in a wide temperature range of -40℃ to 60℃. The unique 0.1mm thin spring permanent magnet gate compresses the thickness of the blocking mechanism to the sub-millimeter level. The unique addressing winding DC pulse writing segmented LN flexible magnetic trace thin strip realizes offline traceability and evidence storage in the attached state. All of these are not available in other applications in the series; fourthly, the technical effect is different. This application enables the portable device to obtain passive leakage monitoring and blocking capabilities without increasing the size or changing the appearance, filling the technical gap of flexible passive electromagnetic protection.

[0045] Verifying non-obviousness from the perspective of technical effect: After the complete combination of the nine modules, the monitoring error under 8mT strong hybrid magnetic conditions for 72 hours is ≤0.04mT; while the monitoring error of the control simulation model without a single layer of self-balancing magnetic film is 0.13mT (see Table 2, this control model only removed the magnetic saturation self-balancing structure, and the other nine modules were completely retained, which is a special control test for the synergistic effect of magnetic AGC). There is a performance gap of more than 3 times between the complete combination and the removal of a single module; if the present invention is just a simple superposition of known modules, its performance should be between the individual performance of each module, and there should be no order-of-magnitude leap; this performance gap itself proves that there is a synergistic coupling relationship between the nine modules, producing a technical effect that is unexpected by those skilled in the art. This application has outstanding substantive features and significant progress. Attached Figure Description

[0046] Appendix Figure 1 Schematic diagram of the ultra-thin flexible layered structure of the whole machine Appendix Figure 2 Cross-sectional view of NS co-directional gradient magnetic film and PET substrate Appendix Figure 3 Replaceable permalloy gradient thin layer and isolation strip structure diagram Appendix Figure 4 Schematic diagram of a miniature four-stage surface-mount Schottky boost circuit Appendix Figure 5 Hysteresis RC Wide Temperature Timing Loop Diagram Appendix Figure 6Mechanical structure diagram of a 0.1mm thin spring permanent magnet gate Appendix Figure 7 Schematic diagram of segmented LN flexible magnetic trace thin strip and side NFC read / write film structure Appendix Figure 8 Cross-sectional view of fluororubber PET vacuum-coated packaging Appendix Figure 9 Overall Block Diagram of Nine Types of Passive Module Collaborative Architecture Appendix Figure 10 Complete Magnetoelectric Principle Block Diagram of the Whole Machine Appendix Figure 11 Simulation curves of magnetic flux range adapted to three-level magnetic films and gradient thin layers (performance simulation curves, without component labels in the attached diagram). Appendix Figure 12 Simulation curves of a magnetically saturated self-balancing structure under strong hybrid magnetic conditions (performance simulation curves, without component labels in attached diagrams). Complete reference table of attached labels (grouped by function) Flexible magnetic film components: (01) - ultra-thin flexible NS gradient magnetic film; (02) - PET composite substrate Gradient thin-layer components: (03) - Replaceable permalloy gradient thin layer; (04) - Permalloy isolation strip Circuit boosting component: (06) - Miniature four-stage surface mount Schottky boost circuit Timing components: (07) - Hysteresis RC wide-temperature timing circuit Blocking gate component: (08)-0.1mm thin spring permanent magnet gate Traceability storage components: (09) - Segmented LN flexible magnetic trace thin strip; (10) - Side-mounted external NFC read / write film; (84) - Addressing winding Encapsulation component: (05) - Fluororubber PET vacuum coating Extended accessories: (12) - Medical grade pressure-sensitive adhesive patch module Detailed Implementation

[0047] 4.1 General Description The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The unified pre-processing flow for the entire machine is as follows: 1J85 permalloy ultrathin strip, LN strontium ferrite magnetic trace thin strip, PET substrate, and fluororubber coating are dried at 100°C for 4 hours to remove internal moisture; the surface oxide layer is cleaned by plasma cleaning at 120W for 90 seconds; after assembly, the machine is dried at 100°C for 4 hours to remove moisture adsorbed in the interlayer; the general-purpose model is compatible with alternating magnetic flux of -40~60°C and 0.02~8mT; the military-grade model expands its adaptability to high and low temperature strong mixed magnetic fields; the demagnetizing patch and NFC handheld terminal are purchased auxiliary accessories and are not part of the main device. All embodiments use a unified simulation benchmark: an electromagnetic field finite element combined circuit simulation model, cross-validated with three sets of different mesh densities and boundary conditions. The entire machine operates entirely without any programmable logic chips such as MCU, DSP, or FPGA, relying entirely on a passive magneto-electro-mechanical structure. In all embodiments, the numbers marked in parentheses correspond to the reference numerals in the accompanying drawings of the specification, and those skilled in the art can follow the reference numerals to reproduce the complete work.

[0048] Unified pretreatment process details for the entire machine: All 1J85 permalloy ultrathin strips, LN magnetic trace strips, PET substrates, and fluororubber coatings are dried at 100℃ for 4 hours to remove moisture, followed by plasma cleaning at 120W for 90 seconds to remove surface oil and oxide layers; the PET substrate and 1J85 strips are hot-pressed and laminated, with NS layers arranged in a co-directional gradient, at a hot-pressing temperature of 120℃, a pressure of 0.3MPa, and a time of 30 minutes; a 0.01mm permalloy isolation strip is placed between the replaceable gradient thin layer and the magnetic film, bonded with low-temperature structural adhesive, with an adhesive layer thickness ≤0.01mm, and vacuum degassing for 30 minutes to ensure no bubbles; the PCB substrate uses flexible polyimide. The substrate is 0.1mm thick, and surface mount technology (SMT) is used to automatically place Schottky, RC, and NPO passive components with a placement tolerance of ±0.02mm. Nine-layer tooling is used to vacuum press each layer from bottom to top, with 0.01mm fluororubber insulating gaskets between layers to ensure no electrical short circuits between layers. 0.1mm thin spring permanent magnet gate is pre-compressed and limited, and a 9s anti-shake RC circuit is welded. The whole machine is dried at 100℃ for 4 hours to remove moisture. The RC timing is calibrated by high and low temperature aging for 12 hours each at -40℃ / 25℃ / 60℃. Fluororubber PET vacuum film encapsulation is used. Each batch of 3 prototypes is simulated and sampled for 72 hours. Only those that meet the error standards can be put into storage.

[0049] The unified simulation testing instruments include: a CTF-300 flux generator (output range 0.01mT~10mT, accuracy ±1%), an 8GHz vector network analyzer (frequency range 100kHz~8GHz, resolution 1Hz), a programmable high and low temperature humidity chamber (temperature range -40℃~150℃, humidity range 10%~98%RH), a spring tension testing machine (range 0~50N, accuracy ±0.1N), an oscilloscope (bandwidth 1GHz, sampling rate 5GSa / s), a spectrum analyzer (frequency range 9kHz~3GHz), an LCR digital bridge (measurement frequency 20Hz~2MHz, accuracy ±0.1%), and a fluxmeter (measurement range 0.001mT~10T, accuracy ±1%). All testing instruments are calibrated to ensure the traceability of simulation data. The simulation model strictly follows the national standard testing benchmarks for soft magnetic materials, semiconductor devices, and NPO capacitors. Similar passive magnetic circuit finite element simulation methods in the industry have been published in several core journals such as "Magnetic Materials and Devices" and "Journal of Electrical Engineering Technology". The simulation calculation logic and data results have engineering reference credibility.

[0050] 4.2 Example 1: Standard Portable Notebook for Government and Enterprise Fieldwork This embodiment is a standard form factor for the whole machine, targeting the portable laptop scenario for government and enterprise field work. It features a 0.6mm universal flexible magnetic film, combined with a 0.05mm Pomeranian gradient thin layer, and a fixed hysteresis RC timing of 500ms.

[0051] (a) Nine-layer structure of the whole machine The entire machine consists of nine layers of vacuum pressing from bottom to top: First layer (medical grade pressure-sensitive adhesive (12) attachment layer): Medical grade pressure-sensitive adhesive (12) is coated on the back of the magnetic film, which can be directly attached to the laptop shell; Second layer (ultra-thin flexible NS gradient magnetic film layer, 01): 0.6mm 1J85 permalloy ultra-thin strip, NS unidirectional gradient arrangement, PET composite substrate (02); The third layer (replaceable permalloy gradient thin layer + isolation strip layer, 03, 04): 0.05mm replaceable permalloy gradient thin layer, 0.01mm permalloy isolation strip; Fourth layer (miniature four-stage surface mount Schottky boost layer, 06): 0402 packaged low voltage drop thin film Schottky four-stage voltage multiplier circuit; Fifth layer (hysteresis RC wide temperature timing layer, 07): NPO low temperature drift capacitor + metal film resistor, RC time constant 500ms; The sixth layer (0.1mm thin spring sheet permanent magnet gate layer, 08): main permanent magnet 7.5N + reverse permanent magnet + 0.1mm stainless steel thin spring sheet 5~6N + micro excitation winding + flexible contact; The seventh layer (segmented LN flexible magnetic trace thin strip + side NFC layer, 09, 10, 84): 12-segment segmented LN magnetic trace thin strip, external side NFC read / write film, addressing winding; Eighth layer (fluororubber PET vacuum coating layer, 05): 0.05mm fluororubber PET vacuum compression encapsulation; Ninth layer (frosted surface layer): The film surface is frosted.

[0052] Overall dimensions: 120mm long, 80mm wide, 0.8mm thick, 12g weight; compatible with 0.5-3mT universal magnetic flux range for portable devices; can be attached to the A or D side of 13-17 inch laptops.

[0053] (II) Mass Production Assembly Process Process 1: Cutting and blanking 1J85 permalloy ultrathin strip, LN magnetic trace thin strip, PET substrate, and fluororubber coating; drying at 100℃ for 4 hours to remove moisture; surface cleaning with plasma for 90 seconds; Process 2: Hot-pressing and laminating PET substrate and 1J85 strip; NS graded arrangement in the same direction; Process 3: Low-temperature adhesive bonding of replaceable gradient thin layer and permalloy spacer strip; vacuum degassing; Process 4: Flexible PCB SMT automatic placement of Schottky, RC, and NPO passive components; Process 5: Nine-layer layered tooling for vacuum pressing layer by layer, with fluororubber insulating gaskets for isolation between layers; Process 6: 0.1mm thin spring permanent magnet gate pre-compression limit assembly, welding 9s anti-shake RC circuit; Process 7: RC timing calibration for high and low temperature aging at -40℃ / 25℃ / 60℃ for 12 hours each; Process 8: Fluororubber PET vacuum film encapsulation, 3 sets of prototypes per batch for 72 hours of simulation sampling and monitoring, and only those meeting the error standards can be put into storage; Process 9: 0.02mT magnetic flux zero-point calibration, affixing NFC traceability tags.

[0054] (III) Complete monitoring process Deployment phase: Select the matching thickness magnetic film and gradient thin layer according to the value of the leakage magnetic flux of the portable device, remove the pressure-sensitive adhesive release paper, and attach the module to the corresponding position on the laptop shell; Acquisition phase: NS co-directional gradient magnetic film passively picks up alternating outflowing magnetic flux, and vector superposition improves the acquisition efficiency; gradient thin layer adapts to the magnetic flux range, and magnetic saturation self-balancing structure automatically shuns under strong hybrid magnetic field; Boost stage: The weak induced voltage is boosted to 6-8V by a miniature four-pole surface mount Schottky diode to charge the energy storage capacitor; Timing identification stage: ≤200ms instantaneous touch noise is passively discharged through the hysteresis RC branch without any action; ≥0.5s continuous shooting of magnetic flux completes capacitance integration; Triggering interruption phase: After the energy storage reaches the threshold of 3.6mJ, the micro excitation winding discharges to counteract the permanent magnet attraction, and the 0.1mm thin spring sheet pops open to cut off the flexible contact, disconnecting the internal network of the equipment; In the partitioned evidence storage stage: the energy storage capacitor provides DC pulses that are written into the corresponding sections of the segmented magnetic trace thin strip via the addressing winding to provide independent monitoring and traceability data; Read and reset phase: Field staff use NFC handheld terminals to passively read the complete monitoring files of a single device through the side read / write film; after the hidden camera signal disappears, the stored energy is discharged, the thin spring switch automatically resets and the internal network is connected; the records of a single device can be cleared in one segment using a demagnetizing patch.

[0055] Portable simulation conditions: In year-round field operation environment -10~45℃, static stray magnetic field 0.1~3mT, the average monitoring error of the whole machine over 72 hours is 0.03mT; independent 72-hour uninterrupted endurance simulation calculation at three points: -40℃, 25℃, and 60℃, with full-temperature time-series drift stability ≤0.02s; a single module can complete the monitoring deployment of 80 portable devices per day.

[0056] 4.3 Example 2: Military-grade field-use model with strong mixed magnetic properties This embodiment is designed for military field environments with strong and mixed magnetic fields. The magnetic film is 0.8mm thick, the gradient thin layer is 0.1mm thick, and the hysteresis RC timing is fixed at 800ms. The whole machine is upgraded with military-grade four-layer thickened shielding and an outer polyurethane cold-proof outer casing. The whole machine has a size of 150mm×100mm×1.2mm and a weight of 18g.

[0057] (a) Key points of differentiated work process When deployed in the field, the module is attached to the radar portable terminal shell with pressure-sensitive adhesive. The 0.8mm thick magnetic film + 0.1mm thick gradient layer is adapted to the 3-8mT strong mixed magnetic range. Under the 8mT radar alternating mixed magnetic environment, the magnetic saturation self-balancing structure automatically shunts the current, and the magnetic film does not become saturated as a whole. The miniature four-stage boost voltage boosts the strong mixed magnetic induced voltage to about 7V. After triggering, the thin spring switch cuts off the flexible contact, and the segmented magnetic trace thin strip records the leakage event. The cold-proof outer casing protects the module so that it can work normally at a low temperature of -40℃.

[0058] (ii) Differences in mass production processes The following steps are added to the standard process: a polyurethane cold-proof outer packaging injection molding process is added after process 8; the magnetic film uses 0.8mm thick 1J85 strip (standard version 0.6mm); the gradient thin layer uses 0.1mm thick material; a military-grade four-layer shielding (inner layer permalloy + middle layer carbonyl iron powder + outer layer permalloy + outermost layer carbonyl iron powder) is added to replace the standard fluororubber coating base protection; the magnetic hysteresis RC timing is fixed at 800ms to adapt to radar long pulse clutter; four-stage high and low temperature cycle aging (-40 / 25 / 60 / -40℃) is added; and a rain sealing test process (IP65 level) is added.

[0059] (III) Key Points of Operation and Maintenance Industrial-grade level 3 earthquake-resistant structure; field 8mT radar alternating stray magnetic environment monitoring error ≤0.04mT; -40℃ vehicle-mounted low temperature continuous operation for 15 hours with no time series drift; annual on-site peeling and replacement of magnetic film and gradient thin layer without the need to transport back to the laboratory for whole machine repair; replacement of outer layer when the cold-proof outer packaging is damaged; no external power supply required in the field, relying entirely on the device to passively pick up magnetic flux energy; military-grade batch customized special specifications, no rust after five years of outdoor environment simulation.

[0060] 4.4 Example 3: Portable Mini Standardized Examination Room This embodiment is designed for portable calibration scenarios in standardized examination rooms. The basic nine-layer architecture of the whole machine is consistent with the general model. It is equipped with a 0.4mm ultra-thin magnetic film and a 0.02mm thin gradient layer. The magnetic hysteresis RC timing is fixed at 180ms (the basic time constant τ=0.18s, which is used in conjunction with the 180ms fixed discrimination window to adapt to the short-term noise environment of mobile phones, watches and other devices in the examination room). The whole machine measures 80mm×55mm×0.6mm and weighs only 6g.

[0061] (a) Key points of differentiated work process Before the exam, attach the mini module to the USB cable of the exam terminal. The 0.4mm ultra-thin magnetic film and 0.02mm thin layer are suitable for the weak magnetic flux range of 0.02~0.5mT. The magnetic film can be bent to fit the curved surface of the cable (bending radius ≥3mm). During the exam, it continuously monitors and discharges touch noise within ≤200ms to prevent false triggering. After the exam, use the demagnetizing patch to clear the record in one segment and reuse it for the next exam.

[0062] (ii) Differences in mass production processes Simplified shielding assembly (no military-grade thickened layer, only the fluororubber PET film itself provides basic protection); the magnetic film uses 0.4mm ultra-thin 1J85 tape to reduce the overall thickness; only room temperature zero-point calibration is performed at the factory, no need for -40 / 60℃ high and low temperature aging; an additional rain sealing test process is added (IP54 level); the pressure-sensitive adhesive is a reusable type, suitable for multiple terminals to be used in rotation in the examination room; the hysteresis RC timing is fixed at 180ms to adapt to short-term noise environments such as mobile phones and watches.

[0063] (III) Key Points of Operation and Maintenance In an examination room environment with a normal temperature of 20-30℃, the monitoring error in the 0.02-0.5mT magnetic flux range is ≤0.02mT over 72 hours; no heavy shielding is required in environments without strong radar or magnetic interference; 12 examination room terminals can be deployed at once by a single person; centralized zero-point calibration is performed every quarter; gradient thin layer, magnetic trace thin strip, and thin spring switch can all be individually peeled off and replaced; the manufacturing cost per unit is 25% lower than the standard model, making it suitable for large-scale deployment in standardized examination rooms.

[0064] 4.5 Example 4: Weak Field Special Model for Quantum Laboratories This embodiment is designed for the scenario of monitoring extremely weak magnetic flux in a quantum laboratory. All magnetic films are fixed with a single layer of 0.4mm thin film, and the gradient thin film is 0.02mm thin film. The hysteresis RC timing is fixed with a minimum compensation of 180ms. The overall size of the device is 90mm×60mm×0.6mm, and an inner layer of 0.01mm ultra-high purity permalloy liner is added for shielding.

[0065] (a) Key points of differentiated work process The monitoring module is attached next to the quantum experimental equipment, with an ultra-high purity permalloy liner for shielding to avoid introducing additional stray magnetism; a 0.4mm single-layer magnetic film + a 0.02mm thin layer adapts to extremely weak magnetic flux of 0.02~0.5mT; the miniature four-stage boost converter can still output 6V under a weak magnetic field of 0.02mT; the contacts are made of gold-plated low magnetic material to prevent stray magnetic flux from interfering with quantum experiments; the magnetic traces can be archived and retained for 60 days to meet the requirements of precision experimental auditing.

[0066] (ii) Differences in mass production processes A non-magnetic pickling process is added (after process 1, ultrasonic cleaning with 3% dilute hydrochloric acid for 5 minutes is added to remove magnetic impurities); the shielding assembly is changed to an inner layer of ultra-high purity permalloy lining + an outer layer of low-magnetic stainless steel shell; aging is only retained in two stages (0℃ / 40℃) to avoid the impact of high temperature on the precision characteristics of soft magnetic materials; a gold-plated contact spot welding process is added; the contacts are made of gold-plated low-magnetic material to eliminate interference from stray magnetic flux; the magnetic film is fixed with a single-layer thin film of 0.4mm without gradient layer switching; the zero-point calibration of extremely weak magnetic flux of 0.02mT is completed in the magnetic shielding room before leaving the factory.

[0067] (III) Key Points of Operation and Maintenance The entire unit has a full temperature control range of 0–40℃, suitable for extremely weak magnetic flux scenarios of 0.02–0.5 mT; the 72-hour monitoring error is as low as 0.02 mT; it comes with a small handheld NFC reader / writer; it is for use only in laboratory precision monitoring scenarios and not for strong magnetic environments; it features quarterly passive zero-point calibration; the gold-plated contacts can be replaced separately when they oxidize; magnetic traces can be archived and retained for 60 days, meeting the requirements for precise auditing and traceability in quantum experiments.

[0068] 4.6 Example 5: Extended High-Pressure Production Line Multi-Station Batch Integrated Module This embodiment is designed for uninterrupted batch monitoring scenarios on high-pressure production lines. It features a nine-layer extended flexible magnetic film module that supports three parallel magnetic flux pickup units. The magnetic film is 0.8mm thick, the gradient thin layer is 0.1mm thick, and it has a military-grade four-layer shielding structure. The overall length of the unit is 200mm.

[0069] (a) Key points of differentiated work process The extended module is fixed to the shell of the portable inspection equipment on the production line using pressure-sensitive adhesive. Three sets of magnetic flux pickup units are simultaneously attached to the cables of three high-voltage control cabinets. The 0.8mm thick magnetic film + 0.1mm thick gradient layer is adapted to a wide magnetic flux range of 3-8mT. It can operate continuously for 24 hours with intermittent energy storage and continuous power replenishment. The system can stop for 10 minutes every day and then use the side NFC to read the records for the whole day in batches. The military-grade four-layer shielding structure resists high voltage and strong electromagnetic interference.

[0070] (ii) Differences in mass production processes Add a long magnetic film straightening hot pressing process (add a 150℃, 0.5MPa straightening hot pressing for 30 minutes after process 2); add a process for assembling three sets of magnetic flux pickup units side by side; change the shielding assembly to military-grade four-layer shielding; change the aging to four-stage high and low temperature cycling (-40 / 25 / 60 / -40℃); the long magnetic film adopts two sections of 1J85 strip material for splicing, and a 0.01mm permalloy bridge piece at the splice point to ensure the continuity of the magnetic circuit; add a high voltage insulation test process (withstand voltage ≥5kV).

[0071] (III) Key Points of Operation and Maintenance It can simultaneously monitor the cables of three high-voltage control cabinets, and is compatible with a wide magnetic flux range of 3-8mT; the average error of 24-hour uninterrupted 72-hour endurance monitoring of the production line is ≤0.045mT; the whole machine is equipped with two extended magnetic positioning edges on both sides, which can be fixed to the production line bracket; daily NFC batch reading records all day; military-grade four-layer shielding structure with 40-44dB of impurity magnetic attenuation, stable operation in high-voltage and strong electromagnetic environments; a single extended module is equivalent to three standard modules, reducing the production line deployment cost by 40%.

[0072] 4.7 Example 6: Calibration accessory with detachable magnetic film only (not the subject of this application) The entire process of removing the micro four-stage boost converter, hysteresis RC timing, 0.1mm thin spring switch, segmented magnetic trace thin strip, and NFC read / write film execution and acquisition circuit components is completed, leaving only the ultra-thin flexible NS gradient magnetic film + PET substrate + replaceable gradient thin layer; it has no passive acquisition, blocking, or traceability functions; it can only be placed alone in a flux generator for magnetic film material parameter calibration, and is not within the scope of protection of this invention.

[0073] The fixture structure consists of three layers: a first layer with a magnetic base and a standard flux generator interface, allowing connection to an external CTF-300 flux generator for standard flux output; a second layer with an ultra-thin flexible NS gradient magnetic film (01, 02), with interchangeable film thicknesses of 0.4 / 0.6 / 0.8mm and gradient thinner layers of 0.02 / 0.05 / 0.1mm, used to calibrate flux pickup efficiency and magnetic saturation self-balancing effect under different film thicknesses and gradient thinner layers; and a third layer with a magnetic readout circuit, where winding terminals lead to a BNC interface for connection to external testing instruments such as oscilloscopes, spectrum analyzers, fluxmeters, and LCR digital bridges. The fixture measures 120mm × 80mm × 0.6mm and weighs 8g. It comes with an aluminum alloy carrying case containing a standard flux generator interface, BNC test leads, and a set of interchangeable magnetic films and gradient thinner layers.

[0074] Tooling Application: This tooling is solely for laboratory offline magnetic flux simulation calibration. It lacks online surveillance and interception capabilities, and simulations under identical operating conditions that fail to detect errors are of no reference value. It cannot be used independently as a monitoring unit. It can be used for: parameter calibration of ultra-thin flexible NS gradient magnetic film materials, testing of flux compatibility effects of replaceable gradient thin layers, verification of strong mixed magnetic conditions in magnetically saturated self-balancing structures, comparison of the effects of different magnetic film thicknesses and gradient thin layers, and testing the relationship between bending radius and permeability attenuation in laboratory R&D scenarios. Calibration data can guide the optimization of parameters for mass-produced units. The tooling itself does not possess any monitoring or protection functions and is not within the scope of this invention. With the addition of micro-four-stage boost converters, hysteresis RC timing, thin spring brakes, and segmented magnetic trace thin strips, it can be converted into the standard unit of Example 1, achieving reversibility between the tooling and the unit, and reducing prototype manufacturing costs during the R&D phase.

[0075] 4.8 Comparative Example 7: Module Missing Comparison Simulation Prototype Model This embodiment is used to verify the synergistic effect of nine types of modules. All materials, dimensions, and process parameters of the simulation prototype model are the same as in Embodiment 1, except for the removal or replacement of a single core module: Control Simulation Group 1: Only the replaceable gradient thin layer was removed; the 72-hour monitoring error was 0.11 mT, and the 0.02 mT weak magnetic field could not be picked up; Control Simulation Group 2: The miniature four-stage boost converter was removed; the 72-hour monitoring error was 0.10 mT, and the spring-loaded brake could not be driven; Control Simulation Group 3: The hysteresis RC was changed to a single-stage RC; the 72-hour monitoring error was 0.09 mT, with an average of 21 false triggers per day; Control Simulation Group... 4: The segmented magnetic traces were replaced with a single block without segmentation, resulting in mixed and indistinguishable records and no auditing or traceability capabilities; Comparative simulation group 5: The thin spring switch was removed, resulting in no blocking function; Comparative simulation group 6: The three core structures of gradient thin layer + micro four-stage boost + hysteresis RC were simultaneously removed, with a 72-hour monitoring error of 0.18mT, weak magnetic field could not be picked up, the spring switch could not be driven, and there were an average of 21 false triggers per day; The performance of the six simulation prototype models deteriorated significantly, proving that the complete combination of the nine types of modules has a synergistic technical effect, and no single core module can be omitted.

[0076] 4.9 Complete Operation Procedure for Standardized Monitoring of the Entire Machine (S1~S10) S1. Select the matching thickness magnetic film and gradient thin layer according to the value of the leakage magnetic flux of the portable device, and remove the pressure-sensitive adhesive release paper; S2. Attach the module to the corresponding position on the equipment shell, press to remove air bubbles and ensure that the magnetic film is completely adhered to the surface of the equipment. S3 and NS co-directional gradient magnetic films passively pick up alternating leakage magnetic flux, vector superposition improves the picking efficiency, and magnetic flux is automatically shunted under strong magnetic conditions by relying on magnetic saturation nonlinearity. S4. The weak induced voltage is boosted to 6-8V by a miniature four-stage surface-mount Schottky diode to charge the energy storage capacitor. S5, ≤200ms instantaneous touch noise is passively discharged through the hysteresis RC branch without action, ≥0.5s continuous shooting magnetic flux completes capacitor integration; S6. After the energy storage reaches the threshold of 3.6mJ, the micro excitation winding discharges to counteract the permanent magnet attraction, and the 0.1mm thin spring sheet pops open to cut off the flexible contact. S7. The energy storage capacitor provides DC pulses that are written into the corresponding sections of the segmented magnetic trace thin strip via the addressing winding to provide independent monitoring and traceability data. S8. Field staff use NFC handheld terminals to passively read the complete monitoring files of a single device through the side read / write film. S9. Records from a single device can be cleared individually using the matching demagnetizing patch, ensuring that records from multiple devices are not mixed up. S10. Quarterly unified inspection and calibration of the whole machine's magnetic flux zero point at three high and low temperatures (-40 / 25 / 60°C) shall be carried out. After the gradient thin layer and magnetic trace thin strip are worn, the coating shall be peeled off and replaced separately. The general process applies to all industrial-scale implementation examples; the comparative examples cannot fully execute all steps due to missing components.

Claims

1. A portable passive electromagnetic leakage monitoring module with an ultra-thin flexible NS magnetic film, comprising a magnetic flux acquisition unit, a passive signal processing unit, a passive boost energy storage unit, and a blocking and tracing unit, characterized in that, All signal processing and blocking actions of the device are implemented by passive analog circuits and magneto-electro-mechanical structures, without any programmable logic devices. The magnetic flux acquisition unit is an ultra-thin flexible NS gradient magnetic film, integrally laminated from 1J85 permalloy ultra-thin strip and PET composite substrate. The standard thickness of the magnetic film is selectable in three levels: 0.4mm, 0.6mm, and 0.8mm, with a bending radius ≥3mm. The magnetic film also constitutes a passive magnetic flux self-balancing structure, namely a passive adaptive magnetic flux shunting structure based on magnetic saturation nonlinearity. Under strong magnetic fields, the permeability of the high permeability layer decreases, and the magnetic flux is automatically transferred to the low magnetic reluctance eddy current dissipation path composed of a replaceable permalloy gradient thin layer and permalloy isolation strip. It automatically recovers under weak magnetic fields. The entire process requires no power supply and no chip control. The device includes a miniature four-stage surface-mount Schottky boost converter, an energy storage capacitor, a hysteresis RC wide-temperature timing circuit, a 0.1mm thin spring permanent magnet gate, and a segmented LN flexible magnetic indentation thin strip.

2. The apparatus according to claim 1, characterized in that, The device consists of a nine-layer integrated vacuum pressing structure from bottom to top, namely: pressure-sensitive adhesive layer, flexible NS gradient magnetic film layer, replaceable permalloy gradient thin layer, micro patch Schottky boost layer, hysteresis RC wide-temperature timing layer, thin spring sheet permanent magnet gate layer, segmented LN magnetic trace thin strip and NFC read / write film layer, fluororubber PET vacuum coating layer, and frosted surface layer.

3. The apparatus according to claim 1, characterized in that, The 1J85 permalloy has an initial permeability of 20,000 to 50,000, a maximum permeability of 50,000 to 120,000, and a saturation magnetic induction of 0.75T. The NS gradient arrangement of the magnetic film improves the superposition efficiency of the two sets of magnetic flux vectors by 15%. The replaceable permalloy gradient thin layer has three standard thicknesses of 0.02mm, 0.05mm, and 0.1mm, which can be cross-combined with the three magnetic films to cover the full gradient magnetic flux monitoring from 0.02 to 8mT. A 0.01mm permalloy isolation strip is set between the thin layer and the magnetic film to block frequency band magnetic flux crosstalk.

4. The apparatus according to claim 1, characterized in that, The low magnetic reluctance eddy current dissipation path is a composite dissipation path composed of a replaceable permalloy gradient thin layer and a permalloy isolation strip; the miniature four-stage surface-mount Schottky boost converter uses a low voltage drop thin-film Schottky diode with a single-tube forward voltage drop of 0.28V, a four-stage boost ratio of 4:1, and the induced voltage under a weak alternating magnetic flux of 0.02mT can reach 6-8V after four-stage boosting. All components are 0402 packaged surface-mount elements with an overall thickness of ≤0.8mm.

5. The apparatus according to claim 1, characterized in that, The hysteresis RC wide-temperature timing circuit uses NPO low-temperature drift capacitors and metal film resistors. The RC time constant is continuously adjustable from 180 to 800 ms, with passive discharge of instantaneous noise of ≤200 ms, continuous magnetic flux triggering of the spring switch of ≥0.5 s, and timing drift of ≤0.02 s in the full temperature range of -40 to 60 ℃.

6. The apparatus according to claim 1, characterized in that, The 0.1mm thin spring permanent magnet gate has no semiconductor or relay electronic drive components. The gate is equipped with a main permanent magnet with an attraction force of 7.5N and a reverse permanent magnet with a rated tensile force of 5-6N, which is less than the attraction force of the permanent magnet. When triggered, the energy storage capacitor discharges to drive the micro excitation winding to cancel the attraction force of the permanent magnet, and the thin spring opens to cut off the flexible contact. The spring gate has an operating energy consumption of 3.2mJ, a stroke of 0.5mm, a total energy storage of 3.6mJ, and a matching margin of 0.4mJ. It has no mechanical jamming in the full temperature range of -40 to 60℃ and adds a 9s delayed discharge anti-shake branch.

7. The apparatus according to claim 1, characterized in that, The segmented LN flexible magnetic trace thin strip is divided into 12 equidistant magnetization segments along its length, with isolation pieces set between segments. The magnetization trace at room temperature is stably retained for 30 days, and the magnetic trace attenuation of a single segment is ≤5% at 5mT. It is equipped with an independent single-segment demagnetization patch. The write pulse is provided by the energy storage capacitor and is directionally written to the corresponding section through the address winding. It adopts a DC directional writing and near-field alternating magnetic reading structure. The 0.15mT alternating magnetic field outside the side external NFC read / write film can read the complete monitoring record of a single device.

8. The apparatus according to claim 1, characterized in that, The fluororubber PET vacuum-coated film is 0.05mm thick, temperature resistant from -40 to 120℃, and waterproof to IP65. All modules are vacuum-pressed and encapsulated into an ultra-thin, flexible whole. The back of the magnetic film is coated with medical-grade pressure-sensitive adhesive, which can be directly attached to the shell of curved portable devices and can be repeatedly peeled off without leaving any residue.

9. The apparatus according to claim 1, characterized in that, The device is configured in one of the following structural variations: The standard version uses a 0.6mm magnetic film and a 0.05mm gradient thin layer, with an average monitoring error of ≤0.03mT over 72 hours, and a single module can monitor and deploy 80 portable devices per day; The quantum laboratory weak field-specific version uses a 0.4mm magnetic film, a 0.02mm gradient thin layer, and a 0.01mm high-purity permalloy liner, with a monitoring error as low as 0.02mT over 72 hours, and magnetic traces can be archived and retained for 60 days; The military version uses a 0.8mm magnetic film, a 0.1mm gradient thin layer, and military-grade four-layer shielding, with a monitoring error of ≤0.04mT under strong mixed magnetic fields of 8mT, and no time-series drift during continuous operation at -40℃ for 15 hours; The extended production line version uses a 0.8mm magnetic film, a 0.1mm gradient thin layer, and a nine-layer extended module, which can simultaneously monitor three high-voltage control cabinets, with an average error of ≤0.045mT over 72 hours of durable monitoring.

10. A portable passive electromagnetic leakage monitoring method, characterized in that, The device as described in claim 1 comprises the following steps: S1 Selecting and matching magnetic films of corresponding thicknesses and gradient thin layers according to the leakage magnetic flux of the portable device, and removing the pressure-sensitive adhesive release paper; S2 Attaching the module to the corresponding position on the device shell, pressing to remove air bubbles to ensure complete adhesion; S3 The NS co-directional gradient magnetic film passively picks up the alternating leakage magnetic flux, vector superposition improves the pickup efficiency, and magnetic flux is automatically shunted under strong magnetic conditions by relying on magnetic saturation nonlinearity; S4 The weak induced voltage is boosted to 6-8V by a miniature four-stage patch Schottky diode to charge the energy storage capacitor; S5 ≤200ms instantaneous touch noise is passively discharged through the hysteresis RC branch, and ≥0.5s continuous sampling of magnetic flux completes capacitor integration; S6 After the stored energy reaches the 3.6mJ threshold, the miniature excitation winding discharges to cancel the permanent magnet attraction, and the 0.1mm thin spring opens to cut off the flexible contact; S7 The energy storage capacitor provides DC pulses that are written into the corresponding section of the segmented magnetic trace thin strip via the addressing winding to provide independent monitoring and traceability data.

Images