Magnetically Aligned Switch Circuit for Flexible Pressure Sensing

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Solution Overview

Problem

Existing electronic devices face challenges in providing flexible, pressure-sensitive electrical switches and electrodes that can be worn on the human body without causing skin irritation, while maintaining conductivity and flexibility.

Innovation Solution

A magnetically aligned ensemble of conductive particles is embedded in a deformable host material, forming a complete conduction path between terminals upon depression and breaking upon release, using ferromagnetic particles with a conductive outer surface and aligned within a flexible polymer matrix.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conductive particles are dispersed in an elastic material to create a pressure-sensitive switch, then the switch can detect pressure changes, but the particles may cause skin irritation when worn on the human body

Engineering Contradiction:
Improvepressure sensitivityVSAvoidskin irritation
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A ferromagnetic particle layer is introduced as an intermediary between the user's finger and the conductive particles. This particle layer is attracted to the ferromagnetic particles by a magnetic field, enabling pressure detection while preventing direct contact between the user's skin and the conductive particles, thus eliminating skin irritation.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If a magnetic field is applied to align ferromagnetic particles, then the particles form conduction paths for pressure sensing, but the alignment process adds manufacturing complexity

Engineering Contradiction:
Improveconduction path formationVSAvoidparticle alignment process
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The ferromagnetic particles are pre-aligned in a magnetic field during the manufacturing process to form chains that extend across the thickness of the layer. This preliminary alignment ensures that the particles are already positioned to form conduction paths when pressure is applied, simplifying the overall device operation and ensuring reliable pressure sensing functionality.

Inventive Principle:
Principle #10Preliminary action

3Ease of operation

If the host material is made deformable to enable pressure sensitivity, then the switch can respond to pressure changes, but the structural stability may be compromised

Engineering Contradiction:
Improvepressure responsivenessVSAvoidstructural stability
Core Design Contradiction:
Ease of operationVSStability of the object's composition

Solution Approach 1:

The host material is designed as a deformable elastic material that can be pressed between contact assemblies. This flexible structure allows the material to deform under pressure, enabling the ferromagnetic particles to align and form conduction paths, while the elastic nature of the material ensures it returns to its original shape after pressure is released, maintaining structural stability.

Inventive Principle:
Principle #30Flexible shells and thin films

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 a flexible, pressure-sensitive electrical switch or electrode that conforms to the body, maintains conductivity during depression, and avoids skin irritation, offering momentary switching functionality.

Implementation Method 1

Aligned magnetically within the host material is an ensemble of particles each comprising a ferromagnetic material

Methodology Applied
Scientific EffectMagnetic alignment: Magnetic Field

Implementation Method 2

each particle may comprise a ferromagnetic material and a conductive outer surface

Methodology Applied
Scientific EffectFerromagnetism: Ferromagnetism

Implementation Method 3

the ensemble of particles forms a complete conduction path from the first terminal to the second terminal

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 4

a deformable host material arranged between the first terminal and the second terminal

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP3407960B1Magnetically aligned switch circuit
Publication Date: 2025.07.02 MICROSOFT TECHNOLOGY LICENSING LLC
  • EP3407960B1 patent drawingFigure 1
  • EP3407960B1 patent drawingFigure 2
  • EP3407960B1 patent drawingFigure 3~4

AI summary

Examples are disclosed that relate to magnetically aligned switching circuits. One disclosed example provides an electronic component comprising a first terminal, a second terminal, and a deformable host material arranged between the first terminal and the second terminal. Aligned magnetically within the host material is an ensemble of particles each comprising a ferromagnetic material, each particle having greater electrical conductivity than the host material. The ensemble of particles is configured to form at least one complete conduction path from the first terminal to the second terminal.