Electrostatic Slide Clutch Bidirectional Charge Control

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Solution Overview

Problem

Current virtual reality (VR) and mixed reality (MR) systems fail to provide a convincing tactile experience, as they do not effectively simulate the resistance and kinematic forces felt when interacting with virtual objects, which is essential for immersive experiences and various applications beyond VR and MR.

Innovation Solution

An electrostatic slide clutch is used, comprising first and second sheet electrodes with a dielectric layer between them, and a drive circuit that moves charge bidirectionally to influence the normal force between the electrodes, providing realistic resistive force control through wearable devices like gloves, simulating the sensation of interacting with virtual objects by varying frictional forces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If traditional VR/MR systems are used, then visual and auditory immersion is achieved, but tactile realism is insufficient

Engineering Contradiction:
Improvevisual immersionVSAvoidtactile experience deficiency
Core Design Contradiction:
Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces traditional mechanical friction-based clutch systems with an electrostatic clutch mechanism. The electrostatic clutch uses electric fields to generate normal forces between electrodes, which in turn control friction forces. This substitution enables precise, bidirectional control of tactile resistance forces without complex mechanical linkages, directly addressing the tactile experience deficiency while maintaining visual immersion.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent dynamically changes the electrostatic charge parameters on the electrodes to modulate the normal force and consequently the friction force. By varying the amount of charge bidirectionally between first and second electrodes, the system can precisely control the magnitude and direction of resistance forces, providing realistic tactile feedback that complements the visual and auditory immersion.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If unidirectional charge movement is used in electrostatic clutch, then control simplicity is maintained, but bidirectional force control capability is limited

Engineering Contradiction:
Improvecontrol circuit simplicityVSAvoidbidirectional force control
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent employs a single electrostatic clutch mechanism that can perform multiple functions: providing resistance in both directions, enabling bidirectional motion control, and offering variable friction levels. The drive circuit is designed to move charge bidirectionally, allowing the same hardware to adapt to different tactile feedback requirements without needing separate mechanisms for each direction, thus achieving versatility without proportionally increasing complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent implements dynamic charge redistribution between electrodes to achieve bidirectional force control. The drive circuit can rapidly switch charge polarity and magnitude, enabling the electrostatic clutch to adapt its friction characteristics in real-time. This dynamic control allows the system to provide realistic tactile feedback for various virtual object interactions while maintaining a relatively simple overall device structure.

Inventive Principle:
Principle #15Dynamics

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 electrostatic slide clutch effectively enhances the tactile experience in VR and MR environments by providing realistic resistive forces, allowing users to feel the interaction with virtual objects, thereby improving the overall immersion and applicability in various computing device applications.

Implementation Method 1

a drive circuit coupled electrically to the first sheet electrode and to the second sheet electrode and configured to move a variable amount of charge bidirectionally between the first and second sheet electrodes, to influence a normal force between the first and second sheet electrodes

Methodology Applied
Scientific EffectElectrostatic force: Electrostatics

Implementation Method 2

a dielectric layer between the first and second electrodes

Methodology Applied
Scientific EffectDielectric: Dielectric

Data Source

PatentEP3769187B1Electrostatic slide clutch with bidirectional drive circuit
Publication Date: 2023.10.18 MICROSOFT TECHNOLOGY LICENSING LLC
  • EP3769187B1 patent drawingFigure 1
  • EP3769187B1 patent drawingFigure 2
  • EP3769187B1 patent drawingFigure 3

AI summary

An electrostatic slide clutch comprises first and second sheet electrodes, a dielectric layer, and a drive circuit. The dielectric layer is arranged between the first and second sheet electrodes. The drive circuit is coupled electrically to the first sheet electrode and to the second sheet electrode and configured to move a variable amount of charge bidirectionally between the first and second sheet electrodes, to influence a normal force between the first and second sheet electrodes.