Planar NMR Sensor for Flat Sample Measurement

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Solution Overview

Problem

Conventional magnetic resonance devices are limited in measuring larger or flat material samples due to their closed cylindrical construction, which restricts the size of samples that can be measured and limits their application.

Innovation Solution

A magnetic resonance device with a planar magnetic arrangement that creates a static magnetic field using multiple magnetic poles arranged next to each other, combined with an electrical coil to generate an orthogonal magnetic field, allowing for a flat and compact sensor design that can measure samples of various sizes, including flat objects, and enabling portable operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a closed cylindrical design is used for optimal magnetic field homogeneity, then measurement precision is improved, but the device can only measure samples that fit within the cylinder, limiting adaptability

Engineering Contradiction:
Improvemagnetic field homogeneityVSAvoidsample size accommodation
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent transitions from a conventional three-dimensional cylindrical sensor design to a two-dimensional planar sensor design. The magnetic field generating device and measuring device are arranged in substantially parallel planes, creating a flat sensor structure that can measure large or flat samples externally rather than requiring samples to fit inside a closed cylinder. This dimensional change enables the measurement of samples that would otherwise be inaccessible while maintaining magnetic field homogeneity through careful planar arrangement of magnetic poles and coils.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Adaptability or versatility

If a planar magnet arrangement is used to measure larger samples, then adaptability is improved, but device complexity increases due to the need for precise orthogonal field alignment

Engineering Contradiction:
Improvesample size accommodationVSAvoidfield alignment precision
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent employs asymmetric arrangement of magnetic poles and measuring coils within the planar structure. The magnetic poles are positioned at specific asymmetric locations relative to the measuring coils, and the magnetization directions of adjacent magnet segments are rotated by specific angles (e.g., 45 degrees) relative to each other. This asymmetric configuration, when combined with the planar geometry, automatically generates the required orthogonal relationship between the static magnetic field and the alternating magnetic field, simplifying the overall system while maintaining measurement precision.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The magnetic field generating device is divided into multiple magnet segments arranged in a planar configuration, with each segment having specific magnetization directions. This segmentation allows for independent optimization of each segment's contribution to the overall magnetic field, enabling precise control over field homogeneity and orthogonality while maintaining a compact flat design.

Inventive Principle:
Principle #1Segmentation

3Power

If magnet segments with rotated magnetization directions are used to concentrate magnetic flux, then magnetic field strength is improved, but manufacturing precision requirements increase

Engineering Contradiction:
Improvemagnetic field strengthVSAvoidmagnet segment alignment
Core Design Contradiction:
PowerVSManufacturing precision

Solution Approach 1:

The magnet segments are pre-configured with specific magnetization directions (e.g., rotated by 45 degrees relative to adjacent segments) during manufacturing. This preliminary arrangement of magnetization directions ensures that when the segments are assembled in the planar configuration, the magnetic flux is automatically concentrated in the desired direction without requiring complex post-assembly alignment procedures. The carrier plate structure further facilitates this by providing predetermined positions for the magnet segments.

Inventive Principle:
Principle #10Preliminary action

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 planar magnetic arrangement provides a flexible and compact sensor that can measure larger or flat samples with high precision, achieving optimal magnetic field homogeneity and orthogonality, thus enabling NMR measurements on samples that would otherwise be inaccessible, and allowing for the determination of material properties like water content.

Implementation Method 1

a planar magnet arrangement for generating a static magnetic field in the useful volume, wherein the planar magnet arrangement has, on a front side facing the useful volume, a plurality of magnetic poles arranged next to one another along a first extension direction of the planar magnet arrangement, each with an alternating orientation

Methodology Applied
Scientific EffectMagnetic field: Magnetic Field

Implementation Method 2

an electrical coil with at least one winding for generating an alternating magnetic field in the useful volume. The winding is arranged between two directly adjacent magnetic poles of the planar magnet arrangement, so that the alternating magnetic field of the electric coil overlaps the static magnetic field of the planar magnet arrangement essentially orthogonally in the useful volume

Methodology Applied
Scientific EffectElectromagnetic field: Electromagnetic Induction

Implementation Method 3

Nuclear magnetic resonance (NMR) is used in various technical applications to measure material properties. The measurement principle is based on a physical effect in which the material sample under investigation is exposed to external magnetic fields, and the change in the magnetization of the atomic nuclei within the material sample is measured in response to the external magnetic fields

Methodology Applied
Scientific EffectNuclear magnetic resonance: Magnetic Field

Data Source

PatentEP3695213B1Sensor for a nuclear magnetic resonance device
Publication Date: 2025.02.12 ROBERT BOSCH GMBH
  • EP3695213B1 patent drawingFigure 1
  • EP3695213B1 patent drawingFigure 2
  • EP3695213B1 patent drawingFigure 3

AI summary

The invention relates to a sensor (100) for a nuclear magnetic resonance device (300) for determining at least one material property of a material sample arranged in a useful volume (200). The nuclear magnetic resonance device (300) comprises: a magnetic field generation apparatus (101) comprising a planar magnet arrangement (120) for generating a static magnetic field (130, 135, 136, 137) in the useful volume (200), the planar magnet arrangement (120) having a plurality of magnetic poles (131, 132, 133, 134) on a front side (103) facing the useful volume (200), which magnetic poles are arranged adjacent to each other along a first extension direction (X) of the planar magnet arrangement (120) with alternating orientation, and a measuring apparatus (102) for measuring a signal based on nuclear magnetic resonance of the material sample arranged in the useful volume (200), said measuring apparatus comprising an electrical coil (140) having at least one winding (141, 142, 143, 144) for generating an alternating magnetic field (150, 154, 155) in the useful volume (200), the winding (141, 142, 143, 144) being arranged between two directly adjacent magnetic poles (131, 132, 133, 134) of the planar magnet arrangement (120) such that the alternating magnetic field (150, 154, 155) of the electrical coil (140) is superposed with the static magnetic field (130, 135, 136, 137) of the planar magnet arrangement (120) substantially orthogonally in the entire useful volume (200).