Series-Connected Piezo Actuator for Fluid Ejection Without Amplification
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Solution Overview
Problem
Existing fluid ejection devices using piezoelectric elements require amplification mechanisms to achieve sufficient displacement, leading to increased complexity and size, making them less efficient for discharging droplets without amplification.
Innovation Solution
A fluid ejection device utilizing a series-connected actuator composed of solid-state displacement elements, where one end of the elements contacts the moving object, allowing for sufficient displacement without amplification, and includes features like pressurization, differential drive signals, and a biasing member to enhance performance and durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If an amplification mechanism is used to amplify the small displacement of piezoelectric elements, then the displacement amount of the moving object is increased, but the device complexity and size increase
Solution Approach 1:
The actuator is segmented into multiple solid-state displacement elements (first, second, and third elements) connected in series. Each element contributes to the total displacement, allowing the system to achieve sufficient displacement without requiring an external amplification mechanism. The series connection of displacement elements effectively multiplies the total displacement output.
2Length of moving object
If an amplification mechanism is used to amplify the small displacement of piezoelectric elements, then the displacement amount of the moving object is increased, but the device size increases
Solution Approach 1:
The actuator is segmented into multiple solid-state displacement elements (first, second, and third elements) connected in series. Each element contributes to the total displacement, allowing the system to achieve sufficient displacement without requiring an external amplification mechanism. The series connection of displacement elements effectively multiplies the total displacement output.
3Length of moving object
If multiple solid-state displacement elements are connected in series to form an actuator, then the displacement amount is increased without amplification mechanism, but the heat generation between elements may occur
Solution Approach 1:
A resin layer is introduced as an intermediary between adjacent solid-state displacement elements. This resin layer serves as thermal insulation, preventing heat generated by one element from transferring to adjacent elements, thereby avoiding thermal interference and potential damage while allowing the elements to be closely spaced in the series configuration.
4Productivity
If the moving object reciprocates at high speed to discharge high viscosity material, then the productivity is improved, but the reliability of solid-state displacement elements may decrease due to increased stress
Solution Approach 1:
The actuator is divided into multiple solid-state displacement elements connected in series, which distributes the mechanical stress across multiple components rather than concentrating it on a single element. This segmentation enhances the overall reliability and durability of the actuator system during high-speed reciprocation.
Solution Approach 2:
The patent specifies that the solid-state displacement elements have different resonance frequencies, with the element on the back end side having the highest resonance frequency. This parameter optimization ensures that each element operates within its optimal frequency range, maximizing performance while minimizing stress and maintaining reliability during high-speed operation.
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 enables efficient ejection of materials with varying viscosities without the need for amplification mechanisms, miniaturizing the device while improving durability and speed, and preventing heat generation between elements.
Implementation Method 1
an actuator having contact with a back end part of the moving object to reciprocate the moving object... the actuator has a plurality of solid-state displacement elements connected in series to each other
Implementation Method 2
a pressurizing section adapted to pressurize the fluent material reserved in the fluent material reservoir to supply the flow channel with the fluent material
Data Source
AI summary
A fluid ejection device is a fluid ejection device adapted to eject a fluent material, including a fluent material chamber supplied with the fluent material, a moving object, which can reciprocate in the fluent material chamber, a nozzle part having a discharge port communicating with the fluent material chamber, and an inner wall on a periphery of the discharge port on which a tip part of the moving object can contact from the fluent material chamber side, and an actuator having contact with a back end part of the moving object to reciprocate the moving object to thereby discharge the fluent material from the discharge port. The actuator has a plurality of solid-state displacement elements connected in series to each other, and one end of one of the plurality of solid-state displacement elements has contact with the back end part of the moving object.