Acoustically Driven Ferromagnetic Resonance Sensor for Compact EM Detection

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Solution Overview

Problem

Current magnetic field sensors, such as SERF and SQUID sensors, are large, complex, and difficult to integrate, while Hall effect and magnetoresistive sensors compromise on sensitivity, and existing ferromagnetic resonance (FMR) systems are limited to large laboratory setups due to high power requirements and lack of circuit integration.

Innovation Solution

A compact, chip-scale acoustically driven ferromagnetic resonance (ADFMR) sensor device utilizing a voltage oscillator, power splitter, ADFMR circuit, and detector circuit to measure electromagnetic fields with high sensitivity and low noise, enabling integration into printed circuit boards and CMOS-compatible processing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If SERF and SQUID magnetic sensing approaches are used, then sensitivity is improved, but device size and complexity increase

Engineering Contradiction:

ImprovesensitivityVSAvoiddevice complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical magnetic sensing systems (SERF and SQUID) with an acoustically driven ferromagnetic resonance sensor that uses acoustic waves to excite and detect magnetic resonance, eliminating the need for bulky mechanical components while maintaining high sensitivity

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the operating parameters by using acoustically driven ferromagnetic resonance at lower power levels compared to traditional FMR systems, enabling compact integration while preserving measurement precision through resonance detection

Inventive Principle:

Principle #35Parameter changes

2Device complexity

If Hall effect and magnetoresistive sensors are used, then device size is reduced, but sensitivity decreases

Engineering Contradiction:

Improvedevice sizeVSAvoidsensitivity

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent employs mechanical vibration in the form of acoustic waves to drive ferromagnetic resonance, enabling compact sensor design while achieving high sensitivity through resonance amplification of the magnetic signal

Inventive Principle:

Principle #18Mechanical vibration

Solution Approach 2:

The patent changes the operating principle from direct magnetic field detection (Hall effect) to resonance-based detection, allowing compact size while maintaining high sensitivity through the resonant amplification effect

Inventive Principle:

Principle #35Parameter changes

3Measurement precision

If traditional ferromagnetic resonance systems are used, then measurement capability is improved, but power consumption and device size increase

Engineering Contradiction:

Improvemeasurement capabilityVSAvoidpower consumption

Core Design Contradiction:

Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent replaces high-power electromagnetic excitation systems with acoustically driven excitation, using mechanical acoustic waves to induce ferromagnetic resonance at lower power levels, thereby reducing power consumption while maintaining measurement capability

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the excitation method from high-power electromagnetic fields to low-power acoustic wave excitation, enabling ferromagnetic resonance measurement with reduced power consumption and smaller device size

Inventive Principle:

Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The ADFMR sensor provides high sensitivity over a broad frequency spectrum, low power consumption, and ease of integration, making it suitable for applications like magnetoencephalography and other environments where traditional sensors are impractical.

Implementation Method 1

the propagating acoustic wave excites the ferromagnet to resonance or near resonance; wherein the ferromagnet alters the acoustic wave through absorption

Methodology Applied

Scientific EffectFerromagnetic resonance: Resonance

Implementation Method 2

converting the electrical signal to an acoustic wave; wherein the acoustic wave propagates across a magnetic material

Methodology Applied

Scientific EffectAcoustic wave generation: Surface Acoustic Wave

Data Source

PatentUS12366618B2System for an acoustically driven ferromagnetic resonance sensor device

Publication Date: 2025.07.22 50M4 CAPITAL LLC

AI summary

A system for an acoustically driven ferromagnetic resonance (ADFMR) based sensor. The system may include a power source, that provides an electrical signal to power the system, at least one circuit comprising a set of ADFMR circuits, sensitive to external electromagnetic fields, a power splitter, a power combiner and a detector circuit. The system functions to detect and measure external electromagnetic (EM) fields by measuring a perturbation of the electrical signal through the ADFMR circuits due to the EM fields.