Resonant Pressure Sensor Structure for High-Pressure Linearity
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Solution Overview
Problem
Conventional resonant pressure sensors experience a 'balloon effect' at high static pressures, leading to degraded linearity and measurement precision due to peripheral deformation of the diaphragm, making it difficult to achieve accurate measurements under high static pressure conditions.
Innovation Solution
A resonant pressure sensor design featuring a substrate with a cantilever structure and strain-mitigating holes, where the first and second resonators made of semiconductor material with differing impurity concentrations are used to detect static pressure and temperature, providing high linearity and precision across a wide range of static pressures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional diaphragm structure is used in resonant pressure sensors, then the sensor can detect pressure changes through resonance frequency shifts, but the peripheral portion deforms under high static pressure causing the balloon effect and degraded linearity
Solution Approach 1:
The substrate is divided into a fixed portion and a separated portion, with the resonator placed only in the separated portion. This segmentation prevents the entire substrate from deforming uniformly under pressure, isolating the resonator from the balloon effect while maintaining pressure sensitivity through controlled strain in the separated region.
Solution Approach 2:
The substrate is designed with non-uniform properties: the fixed portion provides structural stability and resists deformation, while the separated portion allows controlled strain transmission to the resonator. This local differentiation enables the substrate to maintain overall shape stability while transmitting pressure-induced strain locally to the resonator for accurate measurement.
2Stability of the object's composition
If the substrate is fully fixed to the housing to improve stability, then structural stability is enhanced, but the resonator cannot detect pressure-induced strain
Solution Approach 1:
The substrate is segmented into a fixed portion that provides structural stability and a separated portion that remains free to deform under pressure. The resonator is positioned in the separated portion, allowing it to detect strain while the fixed portion maintains overall structural integrity and resists unwanted vibrations.
Solution Approach 2:
The separated portion of the substrate acts as an intermediary between the fixed substrate and the resonator. It transmits pressure-induced strain to the resonator while being isolated from the constraints of the fixed portion, enabling accurate strain detection without compromising structural stability.
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 ensures high linearity and excellent measurement precision regardless of the static pressure magnitude, effectively mitigating the balloon effect and maintaining accuracy under high static pressure conditions.
Implementation Method 1
detecting a change in a resonance frequency of a resonator, disposed on a surface of the sensor, caused by a strain arising in the resonator
Implementation Method 2
a strain arising in the resonator according to a static pressure applied by the pressure-receiving fluid
Data Source
AI summary
A resonant pressure sensor with improved linearity includes a substrate including a substrate-fixed portion fixed to a housing-fixed portion and a substrate-separated portion separated from the housing-fixed portion in a first direction; a first resonator disposed in the substrate-separated portion to detect a change of a resonance frequency based on a strain caused by static pressure applied by a pressure-receiving fluid interposed in a gap between the housing-fixed portion and the substrate; a first electrode extending along a second direction to output an excitation signal to the first resonator; a second electrode that extends along the second direction and from which the first resonator outputs a signal having the resonance frequency; and a processor that measures the static pressure based on the detected change.