Needle-Shaped Magnetic Sensor for Precise Particle Density Detection
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Solution Overview
Problem
Existing magnetic sensors face challenges in accurately measuring the density of magnetic particles due to the shape and material of the substrate, which affects the magnetic field measurement, and achieving a fine enough probe size for precise detection.
Innovation Solution
A miniaturized magnetic sensor with a needle-shaped detecting part, featuring a substrate cut into a needle shape with MR elements, lead conductors, and a protection film, made from hard materials like AlTiC, allowing for a fine needle of less than 150 μm that is both accurate and robust, minimizing shape-related interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a plate-shaped substrate with steps is used to support the MR element, then the MR element can be positioned to detect magnetic field with high sensitivity, but the substrate shape and material interfere with the magnetic field measurement, reducing measurement accuracy
Solution Approach 1:
The invention extracts the MR element from the plate-shaped substrate configuration and positions it at the tip of a needle-shaped probe. This separation removes the harmful interference from the substrate shape and material, allowing the MR element to detect magnetic field without being affected by the probe body, thereby achieving both high sensitivity and accurate measurement.
Solution Approach 2:
The invention transitions from a two-dimensional plate-shaped substrate to a three-dimensional needle-shaped probe with the MR element positioned at the tip. This dimensional change allows the detection element to be isolated from the support structure, eliminating magnetic field interference while maintaining mechanical support functionality.
2Measurement precision
If the probe size is reduced to minimize shape effect, then measurement accuracy improves, but the probe becomes more fragile and difficult to manufacture
Solution Approach 1:
The invention uses a composite structure combining a needle-shaped probe with an integrated MR element and protection film. The probe is made of hard material (such as AlTiC ceramic) providing strength, while the MR element and protection film are integrated onto the probe surface. This composite approach enables the probe to be both fine (less than 150 μm) and strong, overcoming the fragility issue of miniaturized probes.
Solution Approach 2:
The invention applies a protection film onto the needle-shaped probe to protect the MR element and the probe structure. This thin film layer provides mechanical protection and enhances the probe's durability without adding significant size, allowing the probe to remain fine while gaining the strength needed for practical use.
3Measurement precision
If a fine needle probe is used to reduce shape interference, then measurement accuracy improves, but the probe becomes more difficult to manufacture and less robust
Solution Approach 1:
The invention merges the probe structure, MR element, and protection film into a single integrated needle-shaped component. The MR element and protection film are formed directly onto the needle-shaped probe during the manufacturing process, eliminating the need for separate assembly steps. This integration simplifies manufacturing while achieving the fine needle design necessary for accurate measurement.
Solution Approach 2:
The invention changes the material parameter of the probe to hard material (such as AlTiC ceramic) to enhance strength and manufacturability. This material parameter change allows the probe to be manufactured as a fine needle (less than 150 μm) while maintaining the robustness needed for practical application, overcoming the manufacturing difficulties of miniaturized probes.
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 enables highly accurate and sensitive detection of magnetic particle density without shape-related interference, with the fine needle design providing high strength and rigidity, and the use of hard materials ensuring durability and precise measurement capabilities.
Implementation Method 1
a magnetic sensor, having a magnetoresistive effect (MR) element as an element for detecting magnetic field
Data Source
AI summary
A magnetic sensor has a needle-shaped detecting part. The needle-shaped detecting part includes a substrate cut to have a needle shape, at least one MR element formed on the substrate, at least two lead conductors formed on the substrate, one end of the conductor being electrically connected to at least one MR element, and a protection film covering the at least one MR element and the at least two lead conductors.