Composite Piezoelectric Actuator for Scalable Haptic Feedback

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional haptic feedback technologies in electronic devices, such as electromagnetic actuators and monolithic piezoelectric ceramics, face challenges like scalability, power consumption, fragility, and integration issues, limiting their effectiveness in providing rich sensory experiences.

Innovation Solution

The use of composite piezoelectric actuators, configured as 'haptic tape' with adhesive properties, which can be easily integrated and provide scalable, flexible, and efficient haptic feedback by adjusting viscoelastic characteristics and resonant frequencies, serving as both an actuator and sealant between touch sensitive and display layers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If conventional electromagnetic actuators (ERM, LRA) are used for haptic feedback, then haptic effects can be generated, but the devices suffer from scalability limitations, high power consumption, and integration difficulties

Engineering Contradiction:
Improvepower consumptionVSAvoidscalability
Core Design Contradiction:
Use of energy by moving objectVSProductivity

Solution Approach 1:

The patent changes the fundamental operating parameters by transitioning from electromagnetic actuation to piezoelectric actuation. Piezoelectric materials respond to electrical voltage by producing mechanical deformation, operating at different electrical parameters (high voltage, low current) compared to electromagnetic actuators, thereby reducing power consumption while improving scalability to different device sizes

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs composite piezoelectric materials that combine piezoelectric ceramics or polymers with flexible substrates and electrode layers. This composite structure maintains the low power consumption benefits of piezoelectricity while adding flexibility and scalability for integration into various electronic device form factors

Inventive Principle:
Principle #40Composite materials

2Use of energy by moving object

If monolithic piezoelectric ceramics are used for haptic feedback, then power consumption is reduced, but the actuators become fragile and difficult to integrate

Engineering Contradiction:
Improvepower consumptionVSAvoidmechanical strength
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The patent replaces fragile monolithic piezoelectric ceramics with composite structures that include piezoelectric materials bonded to flexible substrates. This composite construction maintains the energy efficiency of piezoelectric actuation while dramatically improving mechanical strength, flexibility, and reliability for integration into consumer electronics

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent utilizes thin-film piezoelectric structures deposited on flexible substrates, replacing rigid monolithic ceramics. These thin-film composite structures provide the necessary mechanical strength and flexibility while maintaining low power consumption, enabling reliable integration into various electronic device configurations

Inventive Principle:
Principle #30Flexible shells and thin films

3Adaptability or versatility

If haptic actuators are integrated into touch-sensitive displays, then user experience is enhanced, but the device complexity and integration difficulty increase

Engineering Contradiction:
Improveuser experienceVSAvoidintegration complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent merges the haptic actuator structure with the touch-sensitive display structure by bonding piezoelectric elements directly to the display assembly. This integration combines multiple functions (display, touch sensing, and haptic feedback) into a unified structure, reducing overall device complexity while enhancing user experience through synchronized multi-sensory interaction

Inventive Principle:
Principle #5Merging (Combining)

4Ease of manufacture

If adhesive material is added to composite piezoelectric assembly, then ease of integration is improved, but the device complexity increases

Engineering Contradiction:
Improveease of integrationVSAvoidstructure complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent makes the composite piezoelectric assembly multi-functional by incorporating adhesive layers that enable both mechanical bonding and sealing functions. This single integrated component serves multiple purposes (haptic actuation, structural bonding, and environmental sealing), simplifying the overall device assembly process while maintaining ease of integration without significantly increasing structural complexity

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

Composite piezoelectric actuators offer improved mechanical strength, reduced power consumption, and enhanced user experience through adjustable haptic effects, while being robust enough to withstand device stresses and easily integrated into consumer products.

Implementation Method 1

a composite piezoelectric layer between the first electrode layer and the second electrode layer, and a drive circuit configured to apply a voltage to the first electrode layer or the second electrode layer to generate a haptic effect

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentEP3104256B1Haptic feedback using composite piezoelectric actuator having a cut-out
Publication Date: 2021.08.04 TDK ELECTRONICS AG
  • EP3104256B1 patent drawingFigure 1~2B
  • EP3104256B1 patent drawingFigure 3~4

AI summary

The present invention provides an electronic device comprising a touch sensitive layer configured to sense if an object touches the touch sensitive layer and to sense where the touch sensitive layer is contacted; a display layer configured to visually display images; a composite piezoelectric assembly that is substantially planar and has a cut-out so that the composite piezoelectric assembly forms a frame around the touch sensitive layer and forms a seal with the touch sensitive layer to protect the display layer, wherein the composite piezoelectric assembly comprises a first electrode layer, a second electrode layer, and a composite piezoelectric layer between the first electrode layer and the second electrode layer, and a drive circuit configured to apply an alternating voltage to the first electrode layer and the second electrode layer