Passive Pressure Sensor Using Piezoelectric Resonator

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Solution Overview

Problem

Existing pressure sensors with active electronic components have limited temperature tolerance and reliability issues in harsh environments, making them less suitable for high-temperature applications and more expensive compared to those using only passive components.

Innovation Solution

A pressure sensor design that employs a diaphragm separator and a flexure structure to exert a force proportional to fluid pressure onto a piezoelectric resonator, allowing for pressure sensing without active electronic components, enabling operation across a wide temperature range and reducing costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If active electronic components are used in pressure sensors, then measurement precision and signal processing capability are improved, but temperature tolerance and reliability in harsh environments deteriorate

Engineering Contradiction:

Improvepressure sensing accuracyVSAvoidreliability in high temperature environment

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent removes active electronic components from the pressure sensor design, extracting only the passive piezoelectric resonator element that can withstand harsh environments. This eliminates the reliability issues associated with active components while maintaining pressure sensing capability through the passive resonator's frequency response.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces electronic signal processing with a mechanical resonance-based sensing mechanism. The piezoelectric resonator mechanically responds to pressure changes through frequency shifts, eliminating the need for active electronic components that would degrade in high-temperature environments.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Ease of operation

If active electronic components are used in pressure sensors, then signal processing capability is improved, but device cost increases

Engineering Contradiction:

Improvesignal processing capabilityVSAvoidmanufacturing cost

Core Design Contradiction:

Ease of operationVSEase of manufacture

Solution Approach 1:

The patent employs inexpensive passive piezoelectric resonator materials that can be manufactured at lower cost compared to active electronic components. The simplified structure without active electronics reduces manufacturing complexity and material costs while maintaining adequate signal processing through the resonator's inherent frequency response characteristics.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Reliability

If only passive components are used in pressure sensors, then temperature tolerance and reliability are improved, but measurement precision may deteriorate

Engineering Contradiction:

Improvetemperature toleranceVSAvoidpressure sensing accuracy

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The patent utilizes mechanical vibration resonance of the piezoelectric resonator to achieve precise pressure measurements. The resonator's natural frequency responds to applied pressure, providing accurate measurement capability through vibration-based detection without requiring active electronic components.

Inventive Principle:

Principle #18Mechanical vibration

Solution Approach 2:

The patent measures pressure by detecting changes in the resonator's operating frequency parameter. As pressure is applied, the resonator's frequency shifts in a measurable way, providing precise pressure sensing capability through parameter change detection while maintaining passive component reliability.

Inventive Principle:

Principle #35Parameter changes

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 allows for reliable and cost-effective pressure sensing in high-temperature environments, maintaining the structural integrity of the piezoelectric resonator while accurately measuring fluid pressure through frequency changes proportional to the applied force.

Implementation Method 1

a piezoelectric resonator. A first resonator interface section of the flexure structure is in contact with a first edge of the piezoelectric resonator. The flexure structure exerts a load proportional to the imparted force onto the first edge of the piezoelectric resonator

Methodology Applied

Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentUS9506828B2Passive pressure sensing

Publication Date: 2016.11.29 CHEVRON USA INC

AI summary

A pressure sensor for sensing pressure of a fluid includes a diaphragm separator and a flexure structure. The diaphragm separator exerts an imparted force on the flexure structure, where the imparted force is proportional to fluid pressure exerted on the flexure structure. The pressure sensor further includes a piezoelectric resonator. A first resonator interface section of the flexure structure is in contact with a first edge of the piezoelectric resonator. A second resonator interface section of the flexure structure is in contact with a second edge of the piezoelectric resonator. The first edge and the second edge are opposite narrow edges of the piezoelectric resonator. The flexure structure exerts a load proportional to the imparted force onto the first edge of the piezoelectric resonator.