Magnetic Sensor With Piezomagnetic Alternating Field Generation
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Solution Overview
Problem
Existing magnetoelectric sensors have a limited capability to detect low magnetic field intensities, restricting their usage scenarios, such as in applications like magnetocardiograms or magnetoencephalograms.
Innovation Solution
A magnetic sensor design incorporating a piezomagnetic component, a magnetostrictive component, and a piezoelectric component, where the piezomagnetic elements produce an alternating magnetic field that is stacked with the measured field to form a magnetic circuit, allowing for the detection of low-intensity magnetic fields without the need for macro coils, and enabling sensitivity even when the magnetic field is disconnected.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional magnetoelectric sensors use magnetostrictive and piezoelectric materials stacked together, then they can convert magnetic field to electric signal, but they have weak capability to detect low magnetic field intensity
Solution Approach 1:
The sensor is divided into multiple functional layers including piezomagnetic component, magnetostrictive component, and piezoelectric component, each performing specific functions. The piezomagnetic layer generates alternating magnetic field while the magnetostrictive layer detects the total magnetic field, and the piezoelectric layer converts the detection to electrical signal. This segmentation allows the sensor to achieve high sensitivity for low magnetic field detection through the synergistic effect of different material properties.
Solution Approach 2:
The sensor employs a composite structure combining piezomagnetic materials, magnetostrictive materials, and piezoelectric materials. The piezomagnetic material generates alternating magnetic field, the magnetostrictive material converts magnetic field to mechanical deformation, and the piezoelectric material converts deformation to electrical signal. This composite material approach enables the sensor to detect low magnetic field intensities by leveraging the unique properties of each material class.
2Measurement precision
If magnetoelectric sensors are designed with simple structure, then they are easier to manufacture, but they have limited detection range for low magnetic field intensities
Solution Approach 1:
The sensor transitions from detecting only static magnetic fields to detecting alternating magnetic fields by introducing the piezomagnetic component that generates time-varying magnetic fields. This dimensional change in the magnetic field detection capability allows the sensor to measure low magnetic field intensities by modulating the magnetic field in the time domain, thereby expanding the detection range without proportionally increasing manufacturing complexity.
Solution Approach 2:
The sensor utilizes changes in magnetic field parameters (from static to alternating) to enhance detection capability. The piezomagnetic component modulates the magnetic field at specific frequencies, allowing the magnetostrictive and piezoelectric components to detect low-intensity fields through frequency-domain analysis. This parameter change approach enables extended detection range while maintaining relatively simple manufacturing processes.
3Measurement precision
If magnetoelectric sensors use traditional magnetostrictive-piezoelectric coupling, then they can detect magnetic fields, but they require offset fields and macro coils which increase device complexity
Solution Approach 1:
The piezomagnetic component serves a dual function: it generates the alternating magnetic field needed for detection and simultaneously acts as part of the sensing mechanism. This self-service approach eliminates the need for separate macro coils to generate alternating fields and removes the requirement for external offset fields, as the piezomagnetic material inherently provides the necessary magnetic field modulation for sensitive detection.
Solution Approach 2:
The invention extracts and eliminates the need for macro coils and external offset field generators from the sensor system. By using the piezomagnetic component to generate the alternating magnetic field internally, the design removes these external components, thereby reducing device complexity while maintaining or enhancing sensitivity through the integrated field generation and detection mechanism.
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
This design enhances the detection range of low magnetic field intensities, expands usage scenarios, and maintains sensitivity, eliminating the need for offset fields and macro coils, while improving noise suppression and sensitivity through the use of high-magnetoconductivity materials and specific material combinations.
Implementation Method 1
the first piezoelectric element and the second piezoelectric element are electrically connected to a power supply circuit, and produce first deformation
Implementation Method 2
the first deformation is applied to the first piezomagnetic element and the second piezomagnetic element to produce an alternating magnetic field HAC
Implementation Method 3
the alternating magnetic field HAC is stacked to the measured magnetic field HDC to form a magnetic circuit, so that the first magnetostrictive element produces second deformation
Implementation Method 4
the second deformation and the third deformation produce a first electric potential and a second electric potential on the third piezoelectric element and the fourth piezoelectric element, respectively
Data Source
AI summary
A magnetic sensor includes a piezomagnetic component which includes a first piezomagnetic element and a second piezomagnetic element that are arranged opposite to each other, a magnetostrictive component which includes a first magnetostrictive element and a second magnetostrictive element arranged opposite to each other on the same side of the first piezomagnetic element and the second piezomagnetic element, respectively, and a piezoelectric component which includes a first piezoelectric element deposited underneath the first piezomagnetic element, a second piezoelectric element deposited underneath the second piezomagnetic element, a third piezoelectric element deposited underneath the first magnetostrictive element, and a fourth piezoelectric element deposited underneath the second magnetostrictive element. The first piezoelectric element and the second piezoelectric element are electrically connected to a power supply circuit, and produce first deformation, which is applied to the first piezomagnetic element and the second piezomagnetic element to produce an alternating magnetic field.