Magnetoelectric Micro-Beam Sensor for Ultra-Low Power Magnetic Detection
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Solution Overview
Problem
Current magnetic field sensors lack the desired sensitivity and power efficiency, with most operating at low sensitivity levels (<10−10 Tesla/Hz1/2) and high power dissipation (>10 mW), limiting their effectiveness in naval environments for detecting underwater vehicles and other threats.
Innovation Solution
A magnetoelectric composite sensor utilizing a free-standing magnetoelectric micro-beam resonator with magnetostrictive and piezoelectric layers, exploiting structural resonance and thin film deposition for enhanced sensitivity and low power consumption, achieving sensitivity in the 100 pT/Hz1/2 range with power dissipation two orders of magnitude lower than existing technologies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional magnetic field sensors (fluxgate, giant magnetoresistance, giant magnetoimpedance) are used, then magnetic field detection capability is achieved, but power consumption is high (several mW or greater)
Solution Approach 1:
The patent employs a magnetoelectric composite structure consisting of a magnetostrictive layer (e.g., CoFeB, Metglas) and a piezoelectric layer (e.g., PMN-PT, PZT). The magnetostrictive layer converts magnetic field changes into mechanical strain, which is then transduced into electrical signals by the piezoelectric layer. This composite approach enables passive detection with ultra-low power consumption (nanowatt to picowatt range) while achieving high sensitivity (100 pT/√Hz range), resolving the contradiction between detection capability and power consumption.
2Use of energy by moving object
If magnetoelectric composite structures are used, then power consumption is reduced, but device size is large
Solution Approach 1:
The patent segments the magnetoelectric composite into thin-film layers deposited on a flexible substrate, allowing the device to be divided into functional components that can be miniaturized. The magnetostrictive and piezoelectric layers are deposited as thin films (micrometer to nanometer scale), enabling the overall device volume to be reduced while maintaining the composite material benefits for low-power operation.
Solution Approach 2:
The patent transitions from bulk magnetoelectric composites to thin-film microbeam resonators, exploiting the dimensional reduction to achieve miniaturization. The microbeam structure with clamped-clamped or cantilever configuration allows the device to operate in a reduced dimensional space while maintaining mechanical resonance functionality, thereby reducing device volume without sacrificing low-power performance.
3Measurement precision
If macro-ME laminates are used, then magnetoelectric efficiency is high, but device size is large and miniaturization is difficult
Solution Approach 1:
The patent employs thin-film deposition techniques to create flexible magnetoelectric microbeam structures. The thin films of magnetostrictive and piezoelectric materials are deposited on flexible substrates, allowing the device to achieve high magnetoelectric efficiency through controlled layer thickness and composition while enabling miniaturization to micrometer-scale dimensions, thus resolving the contradiction between sensitivity and size.
Solution Approach 2:
The patent optimizes the physical parameters of the thin-film layers including thickness, composition, and crystal orientation to maximize magnetoelectric coupling efficiency. By carefully controlling deposition parameters and layer structure, the device achieves high sensitivity in a miniaturized form factor, overcoming the limitation of macro-scale ME laminates.
4Volume of moving object
If thin film deposition and reduced dimensionality are used, then device size is reduced, but manufacturing complexity increases
Solution Approach 1:
The patent employs standard semiconductor thin-film deposition techniques (sputtering, chemical vapor deposition, atomic layer deposition) that are universally applicable and well-established in the microelectronics industry. These multi-functional deposition processes can create multiple layers with different properties in a single fabrication sequence, enabling miniaturization while maintaining ease of manufacture through compatibility with existing manufacturing infrastructure.
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 solution provides high sensitivity and ultra-low power consumption, enabling detection of magnetic fields with improved signal-to-noise ratio and extended mission duration for autonomous underwater vehicles, while minimizing battery recharging needs.
Implementation Method 1
A magnetoelectric composite sensor utilizing a free-standing magnetoelectric micro-beam resonator with magnetostrictive and piezoelectric layers
Implementation Method 2
A magnetoelectric composite sensor utilizing a free-standing magnetoelectric micro-beam resonator with magnetostrictive and piezoelectric layers
Implementation Method 3
exploiting structural resonance and thin film deposition for enhanced sensitivity and low power consumption
Data Source
AI summary
A high-sensitivity and ultra-low power consumption magnetic sensor using a magnetoelectric (ME) composite comprising of magnetostrictive and piezoelectric layers. This sensor exploits the magnetically driven resonance shift of a free-standing magnetoelectric micro-beam resonator. Also disclosed is the related method for making the magnetic sensor.