Piezoelectric Actuator Vibration Plate Thickness Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Piezoelectric devices, such as ink jet printing heads, face challenges with crack formation in vibration plates due to flexural deformation, particularly when bubbles enter the pressure chamber, leading to excessive deformation and repeated stress, which existing strengthening methods fail to completely prevent.
Innovation Solution
A piezoelectric device design featuring a vibration plate with recesses on a substrate, where the piezoelectric actuator includes a first and second electrode with a piezoelectric layer sandwiched between them, and an active portion with distinct regions to manage deformation, increasing thickness in central regions to suppress deformation compared to edge regions when voltage is applied.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the strength of the vibration plate is increased to suppress crack occurrence, then the durability is improved, but the excessive deformation caused by bubbles cannot be completely avoided
Solution Approach 1:
The patent applies local quality by making the thickness of the vibration plate non-uniform. Specifically, the vibration plate has a first thickness in a first region and a second thickness greater than the first thickness in a second region. This localized thickness variation allows the plate to have enhanced stiffness in specific areas to resist deformation from bubbles while maintaining overall flexibility for normal operation.
Solution Approach 2:
The patent changes the geometric parameter of the vibration plate by varying its thickness distribution. By adjusting the thickness parameter locally rather than uniformly increasing the entire plate thickness, the design achieves improved crack resistance while controlling deformation characteristics. This parameter modification allows optimization of both strength and deformation properties.
2Strength
If the vibration plate is made thicker to prevent cracks, then the strength is improved, but the ejection characteristics may be degraded
Solution Approach 1:
The vibration plate features local quality through spatially varying thickness. The plate has a first thickness in a first region and a second thickness greater than the first thickness in a second region. This localized reinforcement provides necessary strength to prevent cracks while maintaining appropriate flexibility in other regions for optimal ejection performance.
Solution Approach 2:
The vibration plate is segmented into regions with different thickness characteristics. By dividing the plate into a first region with first thickness and a second region with second thickness, the design allows different portions to fulfill different functional requirements - one for strength and crack prevention, another for maintaining ejection characteristics.
3Reliability
If adhesive is poured in cutout portions to strengthen the vibration plate, then crack occurrence is suppressed, but the device complexity increases
Solution Approach 1:
Instead of adding adhesive materials and complex assembly steps, the patent achieves crack suppression through local quality variation in the vibration plate itself. By making the thickness non-uniform with a first thickness in a first region and a second thickness in a second region, the plate gains inherent strength where needed without requiring additional materials or complex manufacturing processes.
Solution Approach 2:
The patent extracts the strengthening function from the adhesive material approach and integrates it directly into the vibration plate structure. By incorporating the reinforcement feature into the base component through thickness variation, the design eliminates the need for separate adhesive application steps and reduces overall device complexity while maintaining crack suppression effectiveness.
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 design effectively reduces crack occurrence in the vibration plate while maintaining the ejection characteristics of ink droplets, reducing power consumption and heat generation, and enhancing the durability of the piezoelectric actuator.
Implementation Method 1
a piezoelectric actuator including a first electrode, a piezoelectric layer, and a second electrode stacked on a surface of the vibration plate
Data Source
AI summary
An active portion of a piezoelectric actuator includes a first region provided in a region opposed to a recess and extending in a first direction, and a second region provided in a region corresponding to a central part in the first direction of the recess, and being configured such that a laminated body including the active portion and a vibration plate has a thickness larger than a thickness of a portion corresponding to the first region and that deformation of the second region is suppressed as compared to deformation of the first region when a voltage is applied between a first electrode and a second electrode.