MEMS Current Sensor with Segmented Conductors and Interference Compensation

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Solution Overview

Problem

Existing current sensors that use magnetic fields to measure electrical current in high voltage applications are large, bulky, and susceptible to environmental interference, leading to reduced accuracy and efficiency.

Innovation Solution

A micro-electromechanical system (MEMS) current and magnetic field sensor that includes a magneto-MEMS component for sensing the magnetic field and an interference-MEMS component for sensing external factors, providing simultaneous mechanical indications of the magnetic field and interference, which are then converted into electrical signals to determine the current without processing delays.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a thick conductor is used to withstand varying current levels, then the current sensor can handle high voltage applications, but the sensor becomes large and bulky

Engineering Contradiction:

Improvecurrent withstanding capabilityVSAvoidsensor size

Core Design Contradiction:

StrengthVSVolume of moving object

Solution Approach 1:

The sensor is divided into multiple thin conductor segments arranged in a specific configuration rather than using a single thick conductor. This segmentation allows the sensor to maintain structural integrity and current handling capability while significantly reducing the overall size and volume of the sensor assembly.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The thin conductor segments are nested or arranged in a compact configuration where multiple conductive elements are positioned in close proximity, creating a space-efficient structure that maintains electrical performance without requiring large physical dimensions.

Inventive Principle:

Principle #7Nested doll (Nesting)

2Strength

If a thick conductor is used to withstand varying current levels, then the current sensor can handle high voltage applications, but the current flow induces heating that reduces efficiency and accuracy

Engineering Contradiction:

Improvecurrent withstanding capabilityVSAvoidheating loss

Core Design Contradiction:

StrengthVSLoss of energy

Solution Approach 1:

Dividing the conductor into multiple thin segments increases the surface area to volume ratio, improving heat dissipation efficiency. The segmented structure allows heat to be distributed and dissipated more effectively across multiple surfaces, reducing temperature rise and associated energy losses.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The use of thin conductor films or shells with optimized geometry provides sufficient current handling capability while maintaining low thermal mass and efficient heat transfer to surrounding structures, minimizing heating effects during operation.

Inventive Principle:

Principle #30Flexible shells and thin films

3Volume of moving object

If MEMS components are used to reduce sensor size, then the sensor can be used in smaller scale environments, but the sensor becomes susceptible to environmental factors that impact accuracy

Engineering Contradiction:

Improvesensor sizeVSAvoidaccuracy in interference environment

Core Design Contradiction:

Volume of moving objectVSReliability

Solution Approach 1:

The sensor incorporates feedback mechanisms that continuously monitor environmental factors affecting the MEMS components and dynamically adjust measurement parameters or compensation algorithms to maintain accuracy despite environmental variations.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The MEMS structure utilizes composite materials with tailored properties that provide both mechanical sensitivity for detection and environmental robustness. The composite construction offers protection against environmental factors while maintaining the required sensing performance.

Inventive Principle:

Principle #40Composite materials

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 MEMS sensor achieves accurate and reliable current measurement with minimal error and reduced size, operating efficiently in environments with interference, and is suitable for smaller scale applications.

Implementation Method 1

a magnetic-to-mechanical converter in operable communication with the first structural component for providing a mechanical indication of the magnetic field

Methodology Applied

Scientific EffectMagnetic-to-mechanical conversion: Lorentz Force

Implementation Method 2

a interference-to-mechanical converter in operable communication with the second structural components for providing a mechanical indication of an interference

Methodology Applied

Scientific EffectInterference-to-mechanical conversion: Electromagnetic Induction

Implementation Method 3

a first mechanical sense component for sensing the mechanical indication from the magnetic-to-mechanical converter based at least in part upon a change in capacitance

Methodology Applied

Scientific EffectCapacitance sensing: Capacitance

Data Source

PatentUS7453256B2Micro-electromechanical system (MEMS) based current and magnetic field sensor

Publication Date: 2008.11.18 ABB SPA

AI summary

A micro-electromechanical system (MEMS) current and magnetic field sensor for sensing a magnetic field produced by a conductor includes a magneto-MEMS component for sensing the magnetic field and an interference-MEMS component for sensing an interference, wherein the magneto-MEMS component and the interference MEMS component are used to provide an indication of the current in the conductor.