Piezoelectric Actuator Segmented Polarization for Liquid Transport

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

In piezoelectric actuators used for liquid transport, polarizing adjoining portions of the piezoelectric layer in opposite directions can lead to weakened polarization, resulting in decreased deformation and reduced liquid transport efficiency.

Innovation Solution

A method where the first active portion of the piezoelectric layer is polarized after the second active portion, using a specific electrode configuration to maximize the change in pressure chamber volume and maintain strong polarization, thereby enhancing liquid transport efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If adjoining portions of the piezoelectric layer are polarized in opposite directions, then the piezoelectric actuator can achieve bidirectional deformation for liquid transport, but the polarization of one portion is weakened by the electric field applied to the other portion, resulting in decreased deformation amount and reduced liquid transport efficiency

Engineering Contradiction:

Improvebidirectional deformation capabilityVSAvoidliquid transport efficiency

Core Design Contradiction:

Adaptability or versatilityVSProductivity

Solution Approach 1:

The piezoelectric layer is divided into multiple independent active portions (first active portion and second active portion), each with its own electrode pair. This segmentation allows each portion to be polarized and operated independently, preventing the electric field from one portion from weakening the polarization of the other, thus maintaining strong polarization and high liquid transport efficiency while achieving bidirectional deformation capability.

Inventive Principle:

Principle #1Segmentation

2Ease of operation

If the piezoelectric layer is polarized in opposite directions at adjoining portions, then the actuator can control liquid flow in different directions, but the amount of deformation decreases due to polarization weakening

Engineering Contradiction:

Improveliquid flow control capabilityVSAvoiddeformation amount

Core Design Contradiction:

Ease of operationVSShape

Solution Approach 1:

Inventive Principle:

Principle #1Segmentation

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 approach maximally suppresses the decrease in liquid transport efficiency by ensuring strong polarization of the first active portion, resulting in greater volume change and improved ink discharge characteristics.

Implementation Method 1

when the voltage is applied between the individual electrode and the common electrode to shrink a portion of the piezoelectric layer by generating the electric field at the portion of the piezoelectric layer interposed between the electrodes

Methodology Applied

Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

polarizing the second active portion in the direction opposite to the predetermined direction by applying a polarizing voltage between the second electrodes; and polarizing the first active portion in the predetermined direction by applying the polarizing voltage between the first electrodes

Methodology Applied

Scientific EffectPolarization: Polarisation

Data Source

PatentUS8402622B2Method for producing liquid transport apparatus including piezoelectric actuator and method for producing piezoelectric actuator

Publication Date: 2013.03.26 BROTHER KOGYO KK

AI summary

When a piezoelectric actuator, having a lower electrode, an intermediate electrode, and an upper electrode respectively on upper surfaces of a vibration plate, a lower piezoelectric layer, and an upper piezoelectric layer mutually stacked, is produced, a voltage of 30 V is applied to the upper and the intermediate electrodes, and −30 V is applied to the lower electrode so that a second active portion, which is included in portions of the piezoelectric layers interposed between the upper and the lower electrodes and from which a portion opposed to the intermediate electrode is excluded, is polarized downwardly. After that, 0 V is applied to the upper and lower electrodes, and 30 V is applied to the intermediate electrode so that a first active portion, which is included in the upper piezoelectric layer and which is interposed between the upper and the intermediate electrodes, is polarized upwardly.