Acoustic Wave Sensor Piezoelectric Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Capacitive acoustic wave sensors have complex structures leading to high sensitivity but are cumbersome, while piezoelectric sensors have simpler structures but lower sensitivity.
Innovation Solution
An acoustic wave sensor with a continuous membrane and a piezoelectric layer having multiple piezoelectric layer portions connected by individual electric contact structures, allowing for enhanced voltage output and noise reduction through differential amplification.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If capacitive acoustic wave sensors are used, then sensitivity is improved, but device complexity increases
Solution Approach 1:
The piezoelectric layer is divided into multiple piezoelectric layer portions (first, second, third portions) with different orientations. This segmentation allows each portion to generate voltage in response to acoustic waves while maintaining a simpler overall structure compared to capacitive sensors with multiple membranes and electrodes.
2Device complexity
If piezoelectric acoustic wave sensors are used, then device complexity is reduced, but sensitivity deteriorates
Solution Approach 1:
The sensor employs a composite structure with piezoelectric layer portions having different crystal orientations (e.g., different c-axis orientations) deposited on a common substrate. This composite approach enables the sensor to maintain simple structure while achieving enhanced sensitivity through the combined effect of multiple piezoelectric portions with complementary characteristics.
Solution Approach 2:
Different regions of the piezoelectric layer are given different local qualities through varying crystal orientations. The first piezoelectric layer portion has a first orientation, the second portion has a second orientation, and the third portion has a third orientation. This local quality variation allows each region to optimally respond to acoustic waves from different directions, thereby enhancing overall sensitivity without increasing structural complexity.
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 increases the net electric voltage and reduces noise levels compared to continuous contact structures, improving sensitivity without the complexity of capacitive sensors.
Implementation Method 1
A deflection of the piezoelectric film induces a voltage in the piezoelectric film that can be detected by a suitable read-out circuit providing an electric signal indicative of characteristics of the acoustic waves to be detected
Data Source
AI summary
An acoustic wave sensor may include: a continuous membrane deflectable by acoustic waves to be detected, and a piezoelectric layer provided on the membrane and including a plurality of piezoelectric layer portions respectively equipped with at least two individual electric contact structures configured to electrically connect the respective piezoelectric layer portions. Electric contact structures associated with different piezoelectric layer portions may be separated from each other.