Piezoelectric Actuator Vibration Plate Thickness Gradient
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing liquid ejection heads, such as ink-jet recording heads, face challenges in ejecting large ink drops due to insufficient displacement of the vibration plate, which can lead to difficulties in ink ejection and potential cracking when attempting to increase displacement by reducing the vibration plate's thickness.
Innovation Solution
A liquid ejection head design featuring a channel-formed substrate with pressure chambers and a vibration plate having a thick-walled portion at the ends and a thin-walled portion at the center, where the piezoelectric actuator's active portion is located at the ends, allowing for increased displacement while minimizing the risk of cracking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the vibration plate is decreased in thickness to increase displacement, then the amount of displacement of the vibration plate increases, but cracks may occur in the vibration plate
Solution Approach 1:
The vibration plate is designed with non-uniform thickness: thinner at the center (where displacement is needed) and thicker at the peripheral portions (where crack resistance is needed). This local variation in thickness allows the plate to achieve large displacement at the center while maintaining structural integrity and resistance to cracking at the edges.
2Length of moving object
If the active portion of the piezoelectric actuator is positioned at the center of the pressure chamber, then the displacement is maximized, but the vibration plate becomes more susceptible to cracking
Solution Approach 1:
The active portion of the piezoelectric actuator is positioned at the peripheral portions of the pressure chamber rather than at the center, corresponding to the thicker regions of the vibration plate. This positioning ensures that the maximum stress and displacement occur in the thinner central region where the plate is designed to flex, while the thicker peripheral regions provide structural support and prevent cracking.
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 configuration enhances the ejection performance by increasing the displacement of the vibration plate, preventing damage, and improving the durability and reliability of the recording head.
Implementation Method 1
a piezoelectric actuator including a first electrode, a piezoelectric layer, and a second electrode laminated on a surface of the vibration plate remote from the pressure chambers
Data Source
AI summary
A piezoelectric actuator includes, in a first direction in which pressure chambers are arranged side by side, an active portion in which a piezoelectric layer is sandwiched between a first electrode and a second electrode in a first area of a vibration plate corresponding to opposite ends of each pressure chamber and does not include the active portion in a second area of the vibration plate corresponding to a center of the pressure chamber. The vibration plate has, in the first direction, a thick-walled portion with a predetermined thickness in the first area and a thin-walled portion thinner than the thick-walled portion in the second area.