Piezoelectric Acoustic Transducer with Series-Connected Detection Regions
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Solution Overview
Problem
Existing acoustic transducers face challenges in achieving high sensitivity and efficient detection of sound pressure while maintaining a compact size and resistance to environmental factors like dust and water droplets.
Innovation Solution
The acoustic transducer design includes a fixed frame with cantilevers having detection and non-detection regions, where electrodes of the detection regions are electrically connected in series, and the piezoelectric film is structured with multiple layers and electrode-free regions to enhance sensitivity and reduce size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the piezoelectric element uses a single detection region, then the device structure is simple, but the sensitivity is insufficient
Solution Approach 1:
The piezoelectric element is divided into multiple detection regions (first detection region, second detection region, etc.) with different electrode configurations. Each region has electrodes connected in series, creating multiple active zones that collectively enhance the overall sensitivity of the transducer while maintaining a manageable structural complexity through modular design.
2Measurement precision
If the piezoelectric element includes multiple detection regions with series-connected electrodes, then the sensitivity increases, but the device size increases
Solution Approach 1:
The patent utilizes the thickness dimension of the piezoelectric element to accommodate multiple detection regions. By stacking detection regions in the thickness direction with intermediate electrodes, the design achieves enhanced sensitivity through multiple active zones without proportionally increasing the planar footprint, thus controlling the overall device size.
Solution Approach 2:
Multiple detection regions are nested within the piezoelectric element structure, with intermediate electrodes positioned between detection regions. This nested configuration allows multiple functional zones to coexist within a compact volume, achieving high sensitivity while maintaining a small device footprint.
3Strength
If the intermediate electrode thickness is increased, then the structural strength and stability improve, but the manufacturing complexity increases
Solution Approach 1:
The patent specifies a particular thickness range for the intermediate electrode (50 nm to 200 nm) to optimize both mechanical strength and manufacturability. This parameter optimization ensures the intermediate electrode is thick enough to provide structural support and electrical connectivity between detection regions, while remaining thin enough to be fabricated using standard thin-film deposition techniques.
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 design increases sensitivity, allows for reduced device size, and enhances resistance to environmental factors, while enabling flexible resonance frequency adjustment through cantilever length and width modifications.
Implementation Method 1
the piezoelectric element includes a lower electrode, a first piezoelectric layer formed over the lower electrode, an intermediate electrode formed over the first piezoelectric layer, a second piezoelectric layer formed over the intermediate electrode, and an upper electrode formed over the second piezoelectric layer
Data Source
AI summary
An acoustic transducer includes a fixed frame; and a piezoelectric element fixed to the fixed frame. The piezoelectric element includes a plurality of detection regions configured to detect a physical quantity, and a non-detection region configured not to detect the physical quantity. Electrodes of the plurality of detection regions are electrically connected in series.