Electropermanent Magnet and MR Fluid Input Device

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Solution Overview

Problem

Existing input devices face limitations in performance and control due to manufacturing tolerances, reliability issues, and high power requirements, particularly in wireless devices, despite advancements in mechanical and electromagnet-based designs.

Innovation Solution

The integration of an electropermanent magnet (EPM) assembly with a magnetorheological (MR) material, where the EPM generates a magnetic field that changes the viscosity of the MR material, allowing for dynamic control of resistance profiles in input elements, such as buttons and scroll wheels, without continuous power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If electromagnets are used to provide dynamic control in input devices, then functionality and control are improved, but power consumption increases significantly

Engineering Contradiction:

Improvedynamic control capabilityVSAvoidpower consumption

Core Design Contradiction:

Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

The patent combines electropermanent magnets with magnetorheological fluid to create a hybrid system that merges the advantages of both technologies. The electropermanent magnet provides dynamic control capability while consuming minimal power, and the magnetorheological fluid translates magnetic field changes into variable resistance profiles, achieving both adaptability and energy efficiency

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The system changes the magnetic field strength parameter of the electropermanent magnet to control the viscosity parameter of the magnetorheological fluid. By varying the magnetic field intensity, the system dynamically adjusts the resistance profile of the input element without requiring continuous high power consumption

Inventive Principle:

Principle #35Parameter changes

2Ease of manufacture

If mechanical-based input elements are used, then manufacturing is simpler, but performance and reliability are limited by manufacturing tolerances

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoidperformance consistency

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent replaces traditional mechanical spring-based resistance mechanisms with a magnetorheological fluid system controlled by an electropermanent magnet. This substitution eliminates dependence on precise mechanical manufacturing tolerances while maintaining ease of manufacture, as the magnetic and rheological properties can be controlled through material selection rather than precision machining

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Adaptability or versatility

If magnetorheological material is used to provide dynamic resistance control, then performance characteristic control is improved, but device complexity increases

Engineering Contradiction:

Improveresistance profile controlVSAvoidsystem complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The electropermanent magnet serves multiple functions: it generates the magnetic field required to control the magnetorheological fluid viscosity, provides structural support for the input element, and enables dynamic switching between different resistance profiles. This multi-functionality reduces overall device complexity despite the advanced materials used

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 solution provides improved control and efficiency in input devices by dynamically adjusting resistance profiles with minimal power usage, enhancing performance and reliability across various modes of operation.

Implementation Method 1

a magnetorheological (MR) material coupled to the input element, the MR material having a viscosity, where the viscosity of the MR material changes based on the magnetic field

Methodology Applied

Scientific EffectMagnetorheological effect: Magnetorheological Fluid

Implementation Method 2

the magnetizing assembly is configured to set an intensity of the magnetic field of the permanent magnet, and the coil is configured to generate a magnetic field and magnetize the permanent magnet

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentUS11301054B1Combining electropermanent magnets and magnetorheological fluid in an input device

Publication Date: 2022.04.12 LOGITECH EUROPE SA

AI summary

Aspects of the invention include a computer peripheral device comprising an input element that operates based on a performance characteristic, an electropermanent magnet (EPM) assembly including a permanent magnet configured to generate a magnetic field and a magnetizing assembly configured to set an intensity of the magnetic field generated by the permanent magnet, and a magnetorheological (MR) material coupled to the input element. The MR material has a viscosity that changes based on the magnetic field and affects the performance characteristic of the input element.