Piezoelectric Actuator Flexible Circuit Assembly

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional piezo bending actuators used in touch screen devices and Tactile Audio Displays are too large and add thickness, with existing connection methods increasing volume and thickness, and pose interference risks due to ungrounded metal carriers and poor mechanical implementation, affecting performance.

Innovation Solution

A piezoelectric actuator assembly using a flexible circuit with a flexible polymer substrate and electrical conductors, where the piezoelectric member is mounted to one side of the substrate, and the conductors are connected to the piezoelectric member at different locations, allowing for efficient electrical connection and shielding, reducing thickness and volume, and improving mechanical robustness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If conventional piezo bending actuators with metal carriers are used, then the actuator can generate localized feedback and sound, but the device size and thickness increase significantly

Engineering Contradiction:

Improveactuator performanceVSAvoidactuator volume

Core Design Contradiction:

PowerVSVolume of moving object

Solution Approach 1:

The patent extracts and removes the metal carrier from the piezoelectric actuator structure, retaining only the essential piezoelectric element and flexible circuit components. This extraction eliminates the bulky metal carrier while preserving the actuator's core functionality of generating localized feedback and sound through piezoelectric effect.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent employs a flexible circuit substrate to replace the rigid metal carrier structure. The flexible circuit provides necessary electrical connections and mechanical support with minimal thickness, enabling the actuator to maintain thin profile while delivering required performance for tactile feedback and audio output.

Inventive Principle:

Principle #30Flexible shells and thin films

2Reliability

If conventional connection methods with metal carriers are used, then electrical connection can be established, but interference risks increase due to ungrounded metal carriers

Engineering Contradiction:

Improveelectrical connection reliabilityVSAvoidelectromagnetic interference

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent converts the previously harmful ungrounded metal carrier structure into a beneficial grounded flexible circuit system. By removing the isolated metal carrier and implementing a grounded flexible circuit substrate, the design transforms potential electromagnetic interference into a shielded, interference-free electrical connection system that enhances reliability.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The flexible circuit substrate serves as an intermediary between the piezoelectric element and the grounding system. This intermediary provides both electrical connection and electromagnetic shielding functionality, mediating between the active piezoelectric component and the ground reference while protecting against interference.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Strength

If conventional rigid connection structures are used, then mechanical implementation can be achieved, but the device thickness and volume increase

Engineering Contradiction:

Improvemechanical robustnessVSAvoiddevice thickness

Core Design Contradiction:

StrengthVSLength of stationary object

Solution Approach 1:

The patent replaces rigid metal carrier structures with flexible circuit substrates that provide mechanical support and electrical connection in a thin-film format. The flexible circuit maintains structural integrity and mechanical robustness while reducing thickness, enabling robust implementation without increasing device volume.

Inventive Principle:

Principle #30Flexible shells and thin films

4Reliability

If existing connection methods are used, then electrical connection can be established, but connection failures occur due to poor mechanical implementation

Engineering Contradiction:

Improveconnection reliabilityVSAvoidmechanical implementation quality

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent merges the electrical connection function and mechanical support function into a single integrated flexible circuit substrate. This consolidation eliminates separate connection components and their associated assembly steps, providing both structural support and electrical connectivity through one reliably manufactured component that reduces connection failure risks.

Inventive Principle:

Principle #5Merging (Combining)

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 thin, efficient, and robust piezo actuator assembly that reduces thickness and volume, minimizes interference, and maintains performance, while offering better shielding and reduced risk of connection failures, suitable for mobile devices and Audio Displays.

Implementation Method 1

at least one piezoelectric member adapted to move when a voltage is applied to the piezoelectric member

Methodology Applied

Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentUS9131039B2Piezoelectric actuator interface and method

Publication Date: 2015.09.08 NOKIA TECHNOLOGIES OY

AI summary

An apparatus including a flexible circuit having a flexible substrate and at least one electrical conductor; and a least one piezoelectric member adapted to move when a voltage is applied to the piezoelectric member. The piezoelectric member is mounted to a first side of the flexible substrate and electrically connected to at least one of the electrical conductors.