ABA Block Copolymer Thermometers for Extended-Area Flow Sensing
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Solution Overview
Problem
Existing aerodynamic measurement techniques, such as pressure taps, pressure sensitive paints, and laser Doppler velocimetry, are limited by complexity, cost, spatial resolution, and operational constraints, while thermal flow meters face challenges with temperature sensitivity and fabrication complexity, especially in measuring low flow densities and extended areas.
Innovation Solution
Development of ABA type block copolymers with tunable high temperature coefficient of resistance, fabricated via RAFT polymerization, which form mechanically robust and elastic membranes for temperature sensing, enabling precise measurement of convective heat transfer coefficients for flow rate determination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If existing aerodynamic measurement techniques (pressure taps, pressure sensitive paints, laser Doppler velocimetry) are used, then flow rate measurement is possible, but device complexity and cost increase
Solution Approach 1:
The patent replaces complex mechanical and optical measurement systems (pressure taps, laser Doppler velocimetry) with a thermal-based measurement system using ABA block copolymers. The polymer's electrical conductivity changes in response to temperature variations caused by convective heat transfer, providing a simpler, more cost-effective method for flow rate measurement while maintaining measurement precision.
Solution Approach 2:
The invention utilizes changes in the electrical conductivity parameter of ABA block copolymers in response to temperature changes. By measuring conductivity variations that result from convective heat transfer coefficients, the system determines flow rate without requiring complex mechanical or optical instrumentation, thus reducing device complexity while preserving measurement accuracy.
2Area of stationary object
If thermal flow meters are used for extended areas, then flow measurement coverage increases, but temperature sensitivity and fabrication complexity become problematic
Solution Approach 1:
The patent employs ABA block copolymers as composite temperature-sensitive materials that combine thermal responsiveness with electrical conductivity. These copolymers consist of hydrophilic A blocks with chelating motifs and a hydrophobic B block, creating a composite structure that maintains high temperature sensitivity across extended areas while enabling straightforward fabrication through solution processing and cross-linking methods.
3Measurement precision
If ABA block copolymers are used for temperature sensing, then temperature responsivity and spatial resolution improve, but manufacturing complexity increases
Solution Approach 1:
The ABA block copolymer is segmented into distinct functional blocks: hydrophilic A blocks containing chelating motifs for metal ion binding, and a hydrophobic B block providing thermal responsiveness. This segmentation enables each block to contribute its specific function, achieving high temperature sensing precision while allowing independent optimization of each block's synthesis and processing characteristics.
Solution Approach 2:
The patent uses metal ions as intermediaries that bind to the chelating motifs in the A blocks of the copolymer. This intermediary binding mechanism translates temperature changes into measurable electrical conductivity changes, enhancing temperature sensing precision while providing a clear, controllable pathway for manufacturing through controlled metal ion incorporation and cross-linking.
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 ABA block copolymers provide high signal-to-noise ratio and spatial resolution, allowing accurate flow rate measurement across extended areas with improved temperature responsivity and conductivity, overcoming limitations of existing technologies.
Implementation Method 1
tunable high temperature coefficient of resistance
Implementation Method 2
improved temperature responsivity and conductivity
Implementation Method 3
the at least one heater layer is configured to generate a constant heat flux through the at least one first thermometer layer, the at least one thermal insulator layer, and the at least one second thermometer layer
Implementation Method 4
thus generating a thermal gradient within the at least one thermal insulator
Implementation Method 5
at least one thermal insulator layer between the first thermometer layer and the second thermometer layer
Implementation Method 6
two flanking hydrophilic A polymer blocks comprising chelating motifs capable of binding with divalent or trivalent cations
Implementation Method 7
accurate flow rate measurement across extended areas with improved temperature responsivity
Data Source
AI summary
ABA type block copolymers as a new class of temperature sensing polymers with tunable, high temperature coefficient of resistance (TCR). A sensor includes a heater, a thermal insulator between two thermometer layers, the heater generating a thermal gradient within the thermal insulator. The thermometers give an indirect measurement of fluid flow around the sensor, based on their temperature readings. The thermometers are flexible layers including ABA block polymers.