Dual-Layer Piezoelectric Actuator for High-Pressure Liquid Transport
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Solution Overview
Problem
Existing liquid transport apparatuses, such as inkjet printers, face challenges in applying high pressure to liquids due to limited deformation of piezoelectric layers, which restricts efficient liquid transport.
Innovation Solution
A liquid transport apparatus utilizing a piezoelectric actuator with two layers where one layer expands or contracts to project towards the pressure chamber, while the other remains inactive, allowing for significant volume change by switching between states to apply high pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single piezoelectric layer is used to deform toward the pressure chamber side, then the structure is simple, but the volume change of the pressure chamber is small and high pressure cannot be applied
Solution Approach 1:
The piezoelectric actuator is divided into two separate piezoelectric layers (first and second layers), each capable of independent deformation. This segmentation allows the first layer to deform toward the pressure chamber while the second layer deforms in the opposite direction, creating a larger cumulative volume change in the pressure chamber and enabling high pressure application.
2Stress or pressure
If both piezoelectric layers are made active with electric fields, then deformation capability increases, but control complexity and energy consumption increase
Solution Approach 1:
The system dynamically switches between different operational states: in the first state, only the first piezoelectric layer is active (with an electric field applied) while the second layer remains inactive; in the second state, only the second layer is active. This dynamic activation allows the actuator to achieve large deformation capability through sequential operation of layers, reducing overall energy consumption compared to keeping both layers continuously active.
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 enables efficient liquid transport by greatly changing the pressure chamber volume, allowing for high-pressure application and improved ink jetting efficiency.
Implementation Method 1
When a driving potential is applied to the individual electrode, a potential difference occurs between the individual electrode and the vibration plate as the common electrode kept at ground potential, and due to this potential difference, an electric field in a thickness direction is generated in a portion, of the piezoelectric layer, sandwiched between these electrodes. Due to the electric field, this portion of the piezoelectric layer contracts in a horizontal direction
Implementation Method 2
This increases the pressure of ink in the pressure chamber, resulting in the jetting of the ink from a nozzle communicating with the pressure chamber
Data Source
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AI summary
A liquid transport apparatus includes: a channel unit; a piezoelectric actuator which applies a pressure to a liquid in a pressure chamber and which has a first and a second piezoelectric layers, a first, a second, and a third electrodes, the first piezoelectric layer covering the pressure chamber and polarized in a thickness direction, the second piezoelectric layer being joined to a surface of the first piezoelectric layer and polarized in a thickness direction, the first electrode being formed on a surface of the first piezoelectric layer, the second electrode being formed on a surface of the second piezoelectric layer, the third electrode being formed between the first piezoelectric layer and the second piezoelectric layer; a driving mechanism which drives the piezoelectric actuator and which has a potential applying mechanism applying potentials to the first, second, and third electrode respectively, and a controller controlling the potential applying mechanism.