Electroactive Polymer Transducer Haptic Feedback via Counter-Voltage

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Solution Overview

Problem

Existing electroactive polymer transducer devices lack compactness, reliability, and ease of production while providing effective haptic feedback, which is crucial for advanced human-machine interfaces in vehicle interiors, where ergonomic and aesthetic demands are high.

Innovation Solution

A method involving a counter-voltage applied to electrically conductive layers with dielectric electroactive polymer material to hinder thickness reduction until a click-point is reached, reversing voltage after the point to enhance haptic feedback, utilizing a stack of alternating plastic and conductive layers produced by 3D printing for integrated actuator and sensing functionality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional electro-mechanical switches are used, then reliable switching function is achieved, but device complexity and assembly complexity increase

Engineering Contradiction:
Improveswitching function reliabilityVSAvoidassembly complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the actuator and sensor functions into a single integrated electroactive polymer transducer device. The multi-layer structure integrates dielectric elastomer layers, electrode layers, and support layers into one compact unit that performs both actuation and sensing functions, eliminating the need for separate electro-mechanical switch components and reducing assembly complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent replaces traditional electro-mechanical switching mechanisms with an electroactive polymer-based system. The dielectric elastomer layers respond to electrical signals by changing shape or thickness, providing actuation without mechanical moving parts, while integrated electrodes detect the switching state, thereby eliminating complex mechanical assemblies while maintaining reliability.

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

2Ease of manufacture

If electroactive polymer transducer device is used, then device compactness and ease of manufacture are improved, but haptic feedback quality deteriorates

Engineering Contradiction:
Improveproduction easeVSAvoidhaptic feedback quality
Core Design Contradiction:
Ease of manufactureVSEase of operation

Solution Approach 1:

The patent applies different material properties to different layers of the transducer device. The dielectric elastomer layers provide flexibility and actuation, while specific support layers and electrode configurations are designed to enhance haptic feedback characteristics. This local optimization of material properties in different regions of the device maintains ease of manufacture while improving operational feedback quality.

Inventive Principle:
Principle #3Local quality

3Duration of action of stationary object

If dielectric elastomer layers are used, then long lifetime and simple operation are achieved, but manufacturing precision requirements increase

Engineering Contradiction:
Improvedevice lifetimeVSAvoidlayer thickness precision
Core Design Contradiction:
Duration of action of stationary objectVSManufacturing precision

Solution Approach 1:

The patent specifies optimized parameter ranges for the dielectric elastomer layers, including thickness between 10-100 micrometers and specific material composition ratios. By defining these parameter ranges, the patent balances the need for manufacturing feasibility with the requirements for device performance and longevity, reducing overly stringent precision requirements while maintaining long device lifetime.

Inventive Principle:
Principle #35Parameter changes

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 compact, reliable, and easily producible electroactive polymer transducer device with excellent haptic feedback, mimicking mechanical switch characteristics, suitable for embedded integration in vehicle dashboards without separate assembly, enhancing user experience through precise pressure sensing and actuation.

Implementation Method 1

plastic material layers (3), each comprising an active area (33) made of an elastic polymer providing an electrostrictive effect

Methodology Applied
Scientific EffectElectrostrictive effect: Electrostriction

Implementation Method 2

reversing the applied voltage by the control unit after the common click-point is passed to support the click operation

Methodology Applied
Scientific EffectElectrostrictive effect: Electrostriction

Implementation Method 3

The felt mechanical resistance against the applied pressure is high in the beginning and decreases after the click-point, which provides an excellent haptic feedback to the user

Methodology Applied
Scientific EffectConductive polymer sensing: Conduction (electrical)

Data Source

PatentEP3900063B1Haptic feedback with electroactive polymer transducer device
Publication Date: 2024.11.06 MOTHERSON INNOVATIONS CO LTD
  • EP3900063B1 patent drawingFigure 1~2
  • EP3900063B1 patent drawingFigure 3~4
  • EP3900063B1 patent drawingFigure 5~7

AI summary

An electroactive polymer transducer device (1) comprising a stack of alternating plastic electroactive material layers (3) and electrically conductive layers (4), deposited on a base film, plate or wall (2), wherein each plastic material layer (3) may comprises at least one active area (33) made of an elastic polymer providing an electrostrictive effect, laterally adjacent to at least one fixation area (31, 32), wherein the electrically conductive layers are arranged in an alternating sequence of first and second electrodes (41, 42) to apply or sense a voltage, is prepared by three-dimensional printing technology, layer-by-layer injection molding or pressure casting.