Piezoelectric Diaphragm Passive Sensor Wireless Interrogation
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Solution Overview
Problem
Existing remotely interrogatable passive sensors face challenges in effectively measuring pressure and acoustic phenomena in hazardous or inaccessible environments, particularly in situations where direct physical measurements are impractical.
Innovation Solution
The development of pressure-sensitive acoustic resonators utilizing a dielectric substrate with an interdigital conductor pattern and a single-crystal piezoelectric diaphragm, which flexes in response to air pressure, allowing for wireless interrogation and measurement of pressure variations through changes in admittance and electromechanical coupling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a piezoelectric diaphragm is used in a passive sensor, then measurement precision for pressure and acoustic phenomena is improved, but the device complexity increases due to the need for wireless interrogation systems
Solution Approach 1:
The patent replaces traditional mechanical pressure sensing mechanisms with a piezoelectric diaphragm that generates electrical signals in response to pressure changes. This substitution enables wireless interrogation and eliminates the need for complex wired connections, thereby improving measurement precision while managing device complexity through non-mechanical signal transmission.
Solution Approach 2:
The piezoelectric diaphragm acts as an intermediary between the pressure field and the wireless interrogation system. It converts mechanical pressure into electrical signals that can be wirelessly transmitted, serving as a mediator that bridges the physical measurement domain and the wireless communication domain, thus improving precision without proportionally increasing overall system complexity.
2Ease of operation
If remote interrogation capability is implemented, then ease of operation in hazardous environments is improved, but loss of information may increase due to signal transmission challenges
Solution Approach 1:
By replacing mechanical readout systems with wireless electromagnetic interrogation, the patent improves ease of operation in hazardous environments where physical access is difficult or dangerous. The wireless signal transmission maintains information integrity by using electromagnetic fields that can penetrate obstacles without requiring physical contact with the sensor.
Solution Approach 2:
The wireless interrogation system creates an electrical signal copy of the pressure information detected by the piezoelectric diaphragm. This electrical copy can be transmitted wirelessly without degrading the original pressure data, allowing remote access while preserving information fidelity through accurate signal replication and transmission.
3Manufacturing precision
If a single-crystal piezoelectric diaphragm is used, then manufacturing precision is improved, but the ease of manufacture decreases due to the complexity of single-crystal fabrication
Solution Approach 1:
The patent applies single-crystal piezoelectric material specifically to the diaphragm region where high precision is critical for accurate pressure sensing, while other parts of the device can use less complex materials. This localized application of high-precision materials improves diaphragm manufacturing precision without requiring the entire device to be fabricated with the same level of complexity.
Solution Approach 2:
The device employs a composite structure combining single-crystal piezoelectric material for the diaphragm with other materials for supporting structures and electrodes. This composite approach allows the critical sensing element to have high manufacturing precision while the overall device can be manufactured using more conventional, easier-to-implement fabrication techniques for the non-critical components.
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
Enables accurate and remote sensing of pressure and acoustic data, suitable for covert surveillance and hazardous environments, with the ability to distinguish between different pressure frequencies and respond to variations effectively.
Implementation Method 1
a single-crystal piezoelectric diaphragm, which flexes in response to air pressure, allowing for wireless interrogation and measurement of pressure variations through changes in admittance and electromechanical coupling
Data Source
AI summary
There are disclosed pressure-sensitive acoustic resonators and remote pressure sensing systems and methods. A pressure-sensitive acoustic resonator includes a conductor pattern formed on a planar surface of a dielectric substrate, the conductor pattern including an interdigital conductor pattern (ICP), and a diaphragm, the diaphragm being a portion of a plate of single-crystal piezoelectric material, the diaphragm having a front surface exposed to an environment and a back surface facing, but not contacting, the ICP.