Variable Thickness Diaphragm Pressure Transducer Strain Optimization

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Solution Overview

Problem

Traditional diaphragm pressure transducers with constant diaphragm thicknesses experience varying strain at different points on the grid due to the mechanical structure, leading to suboptimal strain output when pressurized by a fluid.

Innovation Solution

A diaphragm pressure transducer design featuring a variable diaphragm thickness, specifically a circumferential channel with varying outer and inner radii, is implemented to maximize strain output, with the diaphragm located between the fluidic cavity and the outer surface, enhancing the strain gauge's sensitivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a constant thickness diaphragm is used, then the mechanical structure is simple and easy to manufacture, but the strain output is suboptimal due to varying strain at different grid points

Engineering Contradiction:

Improvediaphragm manufacturing simplicityVSAvoidstrain output

Core Design Contradiction:

Ease of manufactureVSMeasurement precision

Solution Approach 1:

The diaphragm is designed with variable thickness, being thinner at the center and thicker at the edges. This local variation in thickness optimizes the strain distribution across the diaphragm surface, ensuring more uniform strain at different grid points while maintaining manufacturing feasibility through standard fabrication processes.

Inventive Principle:

Principle #3Local quality

2Measurement precision

If a variable thickness diaphragm is used, then the strain output increases by at least 15%, but the manufacturing complexity increases

Engineering Contradiction:

Improvestrain outputVSAvoiddiaphragm structure

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The diaphragm thickness parameter is varied continuously across the diaphragm surface, transitioning from a constant thickness to a variable thickness profile. This parameter change optimizes the strain distribution and increases strain output by at least 15%, while the variable thickness is achieved through standard manufacturing processes to control complexity.

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 variable thickness configuration increases strain output by at least 15% compared to transducers with constant thickness, improving sensitivity and accuracy in pressure measurement.

Implementation Method 1

a strain gauge including a resistive element located on the outer surface

Methodology Applied

Scientific EffectStrain gauge resistive element deformation: Piezoresistive Effect

Data Source

PatentUS11499881B2Variable thickness diaphragm pressure transducer and method

Publication Date: 2022.11.15 WATERS TECHNOLOGY CORP

AI summary

A diaphragm pressure transducer includes a body having an outer surface and a diaphragm, a strain gauge including a resistive element located on the outer surface, a fluidic inlet, and a fluidic cavity enclosed by the body in fluidic communication with the fluidic inlet, the fluidic cavity having an upper surface. The diaphragm is located between the upper surface of the fluidic cavity and the outer surface of the body. The diaphragm includes a variable thickness across a region defined between the upper surface of the fluidic cavity and the outer surface located below the strain gauge.