Thermoreflectance Microscopy for Parallel Thermal Property Mapping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for determining thermal properties of materials are inefficient and time-consuming, particularly when characterizing large areas or volumes of materials with heterogeneous compositions, such as polycrystalline materials used in electronics and nuclear power, due to their reliance on serial measurement techniques that require extensive manual intervention and take years to complete.
Innovation Solution
The use of parallelized spatial domain thermoreflectance (PSDTR) techniques that apply a reflective material to the surface of a sample and utilize frequency modulated pump and probe light to simultaneously measure thermal conductivity and diffusivity across multiple locations, employing a digital light projector (DLP) to illuminate dozens of sites and a lock-in camera to detect reflected light, allowing for high-throughput characterization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If serial measurement techniques are used to determine thermal properties of materials, then measurement precision can be maintained, but productivity is severely limited and characterization time extends to years
Solution Approach 1:
The patent divides the material sample into multiple discrete locations that can be measured simultaneously. By using arrays of pump light sources and probe light detectors positioned at multiple locations across the sample surface, the measurement process segments the characterization task into parallel independent measurements, enabling high-throughput data collection without sacrificing measurement precision at each location
Solution Approach 2:
The patent combines multiple measurement locations into a single experimental setup. By integrating arrays of pump light sources, probe light detectors, and synchronous detection systems across multiple positions simultaneously, the system merges what would traditionally be sequential measurements into a unified parallel measurement process, dramatically increasing productivity while maintaining data quality
2Productivity
If serial measurement techniques are employed, then device complexity can be kept manageable, but productivity remains low and extensive manual intervention is required
Solution Approach 1:
The patent replaces manual mechanical measurement processes with automated optical detection systems. By using pump light sources and probe light detectors positioned at multiple locations, along with synchronous detection electronics, the system automates the measurement process entirely, eliminating the need for manual intervention and extensive operator involvement while achieving high throughput
Solution Approach 2:
The patent creates a universal measurement platform that can characterize thermal properties across multiple locations simultaneously using the same fundamental measurement principles. The pump-probe light system with synchronous detection serves as a multi-functional unit that handles diverse measurement tasks across different material locations and conditions, increasing productivity without proportionally increasing system complexity
3Measurement precision
If frequency modulated pump light and lock-in detection are used, then measurement precision and signal-to-noise ratio improve, but device complexity increases
Solution Approach 1:
The patent employs periodic modulation of the pump light frequency to encode the thermal excitation signal. By modulating the pump light at a specific frequency and using lock-in detection synchronized to this frequency, the system extracts thermal property information with high precision while rejecting background noise and interference, achieving superior measurement precision through frequency-domain separation
Solution Approach 2:
The patent introduces frequency modulation as an intermediary mechanism between the pump light source and the thermal response detection. The modulation frequency acts as a carrier that encodes the thermal excitation, allowing the lock-in detector to selectively amplify and measure the thermal signal at the specific modulation frequency while filtering out other frequencies, thereby improving signal-to-noise ratio and measurement precision
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 approach significantly reduces characterization time from years to weeks by enabling simultaneous measurement of millions of locations, providing rapid insights into material homogeneity and identifying grain boundaries or inconsistencies, thereby enhancing thermal management capabilities in materials used in electronics and nuclear power.
Implementation Method 1
illuminating the surface of the material sample with pump light from a pump light source... modulating an intensity of the pump light
Implementation Method 2
detecting reflected light signals from the reflective material at a photodetector, responsive to reflected light induced via the probe light... determining the thermal property at least partially based on the reflected light
Implementation Method 3
measuring thermal conductivity and diffusivity across multiple locations... determining thermal properties of materials
Data Source
AI summary
Embodiments disclosed herein relate to methods and systems for determining thermal properties of materials by using frequency modulated pump light intensity to cyclically heat a sample, and using probe light to induce reflected light from reflective materials on the surface of the material during the cyclic heating. The pump and probe light may be emitted onto a plurality of locations on a material sample simultaneously. The methods and systems utilize the phase delay between the frequency modulated pump light and the corresponding reflected light to determine the thermal properties of the material at a plurality of the locations on the material sample simultaneously.