Symmetric-Inlet Environmental Sensor Assembly for Fast Accurate Sensing
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Solution Overview
Problem
Environmental sensors face challenges in achieving fast response times due to gas diffusion limitations and thermal imbalances between sensing and reference regions, which affect accuracy and integration in space-constrained applications.
Innovation Solution
The environmental sensor assembly features a package with symmetrically arranged inlets that provide a short diffusion path for target molecules to the sensing region while maintaining thermal homogeneity between the sensing and reference regions, ensuring accurate and rapid readings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a reference region is added to the sensor to improve accuracy, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The sensing region and reference region are merged into a single sensor substrate, sharing common structural support and packaging. This integration reduces overall device complexity while maintaining the dual-region functionality needed for accurate measurements through differential sensing.
Solution Approach 2:
The package structure is designed to expose both the sensing region and reference region to identical thermal environments and fluid conditions. This equipotential exposure ensures that both regions experience the same ambient conditions, allowing the reference region to accurately compensate for environmental variations and improve measurement precision.
2Reliability
If the sensor is placed inside a protective package, then reliability is improved, but response time deteriorates
Solution Approach 1:
The package incorporates thin-walled structures and apertures that provide mechanical protection while minimizing diffusion path length. The thin film design allows gas molecules to rapidly reach the sensing region through the package walls, maintaining fast response times while preserving sensor reliability through protective encapsulation.
Solution Approach 2:
The package structure features localized apertures and thin-walled regions positioned directly adjacent to the sensing region. This local quality optimization creates preferential pathways for rapid gas transport to the sensing area, while other portions of the package maintain robust protective structures, thus balancing response time and reliability.
3Measurement precision
If the package is designed to protect from environmental interference, then measurement precision is improved, but thermal homogeneity deteriorates
Solution Approach 1:
The package is designed with symmetric aperture arrangements and thermally conductive materials that ensure both the sensing region and reference region experience identical thermal environments. This equipotential thermal exposure maintains thermal homogeneity while allowing environmental gas detection, resolving the contradiction between protection and thermal balance.
4Speed
If the diffusion path is shortened to improve response time, then speed is improved, but device complexity increases
Solution Approach 1:
The sensing region is positioned in direct contact with or immediately adjacent to the package exterior surface, creating a zero-dimensional or minimal one-dimensional diffusion path. This dimensional optimization eliminates the need for complex internal channels or cavities, achieving ultra-fast response times through direct external exposure while maintaining simple package geometry.
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
This design enhances response time and accuracy by minimizing thermal imbalances and gas diffusion delays, allowing for compact, self-contained sensors suitable for various applications.
Implementation Method 1
the time necessary for those molecules to reach the sensing area of the sensor is dictated by gas diffusion
Implementation Method 2
it is desirable that the sensing region and the reference region are subject to the same kind of thermal environment
Data Source
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AI summary
An environmental sensor assembly comprising: a package; and an environmental sensor disposed in the package, the environmental sensor comprising a sensing region and a reference region; wherein the package comprises one or more inlets arranged symmetrically with respect to the sensing region and the reference region; and wherein the sensing region is in fluid communication with an external environment through the one or more inlets. A method of manufacturing an environmental sensor assembly is also described.