Thermal Sensor Array Thermopile Segmentation for Gradient Measurement
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Solution Overview
Problem
Existing thermal sensor devices face challenges in accurately measuring temperature gradients due to variations in pixel response, local heating, and external heat sources, leading to inconsistent and inaccurate measurement results.
Innovation Solution
A thermal sensor device comprising a substrate with a cavity and an infrared absorbing membrane suspended over it, equipped with a plurality of thermocouples arranged as first and second thermopiles to measure temperature differentials between cold and hot junctions, allowing for accurate measurement of temperature gradients.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple thermocouples are disposed in a predetermined pattern on the sensor membrane, then temperature gradient compensation is improved, but device complexity increases
Solution Approach 1:
The thermocouple array is segmented into multiple independent measurement channels, each with its own cold and hot junctions positioned at specific locations on the membrane. This segmentation allows independent measurement of temperature gradients at different positions, improving overall measurement precision while maintaining manageable complexity through modular design
Solution Approach 2:
Different regions of the sensor membrane are equipped with thermocouples having different configurations and orientations according to the local thermal gradient patterns expected in those regions. This local optimization ensures accurate temperature gradient measurement at each position without requiring uniform complex arrangements across the entire device
2Measurement precision
If thermocouples are arranged to measure temperature differentials across the membrane, then temperature gradient detection is improved, but manufacturing precision requirements increase
Solution Approach 1:
The thermocouple positions and orientations are predetermined during the design phase based on expected thermal gradient patterns. Cold and hot junctions are pre-positioned at optimal locations before actual manufacturing, allowing the manufacturing process to follow established guidelines rather than requiring high-precision adjustment after fabrication
Solution Approach 2:
The thermocouple arrangement is designed to automatically compensate for typical manufacturing variations through its geometric configuration and measurement algorithm. The system self-adjusts for minor positioning deviations by utilizing the relative measurements from multiple thermocouples, reducing the stringency of individual positioning requirements
3Measurement precision
If additional thermocouples and interpolation techniques are used to determine temperature gradients, then measurement accuracy is improved, but device complexity and processing time increase
Solution Approach 1:
Instead of using sufficient thermocouples to directly measure all temperature gradient components, the invention uses a minimal set of strategically positioned thermocouples that provide enough information for accurate gradient determination through calculated inference. This partial measurement approach reduces device complexity while maintaining measurement accuracy
Solution Approach 2:
The physical measurement system is supplemented with computational algorithms that process the thermocouple signals to determine temperature gradients. This substitution of mechanical measurement complexity with computational processing achieves accurate gradient determination with fewer physical sensors, reducing overall device complexity
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 device provides more accurate measurements of infrared electromagnetic radiation and temperature gradients, enabling precise calibration and identification of temperature distributions across the sensor array, while also allowing for early detection of unreliable temperature measurements due to excessive heat sources.
Implementation Method 1
an infrared absorbing membrane suspended over a cavity in a substrate
Implementation Method 2
a plurality of thermocouples disposed over the first and second beams and the infrared absorbing membrane
Data Source
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AI summary
A thermal sensor array device (100) comprises a substrate having a cavity (291) formed therein. An infrared absorbing membrane (200) is suspended over the cavity from a first and second beams (202, 206), the first beam (202) being thermally coupled at one end thereof to the substrate (Cj1) at a first cold junction and the second beam (206) being thermally coupled at one end thereof to a second substrate cold junction (Cj2). Thermocouples are disposed over the first and second beams (202, 206) and on the membrane (200). The thermocouples are arranged on the first and second beams (202, 206) and the membrane (200) as first and second thermopiles (300, 320). The first and second thermopiles (300, 320) are arranged on the membrane (200) to measure a sum of first temperature differentials between the first substrate cold junction (Cj1) and a hot junction (Hj) on the membrane (200), and second temperature differentials between the second substrate cold junction (Cj2) and the hot junction (Hj) on the membrane. The first thermopile (300) is configured to connect selectively to the second thermopile (320) in series and anti-series.