High-throughput chip-calorimeter using a Bi₂Te₃ thermopile heat flux sensor array.

Area of Science:

• Thermoelectric modules
• Microcalorimetry
• Biosensing

Background:

• Conventional calorimetric systems face throughput limitations.
• Precision thermal analysis is crucial for biological and chemical applications.
• Bismuth telluride (Bi2Te3) thermopile arrays offer potential for advanced heat flux sensing.

Purpose of the Study:

• To develop a high-throughput microcalorimeter using bismuth telluride thermopile arrays.
• To optimize the device for enhanced power sensitivity and dual-mode calibration.
• To validate the platform for real-time metabolic monitoring and rapid antimicrobial susceptibility testing.

Main Methods:

• Utilized finite element analysis for device optimization, focusing on thermocouple height.
• Implemented dual-mode calibration using electrical (Joule heating) and chemical (enthalpy of mixing) references.
• Integrated 8 sensing units with disposable microfluidic chambers for modularity and contamination prevention.

Main Results:

• Optimized thermocouple height to 0.8 mm achieved ~1 V/W power sensitivity.
• Demonstrated accurate real-time monitoring of Escherichia coli metabolism and thermal signatures.
• Achieved 4-hour antimicrobial susceptibility testing (AST) with results consistent with CLSI guidelines for minimum inhibitory concentration (MIC).

Conclusions:

• The developed chip-calorimeter offers a high-throughput solution for chemical reaction heat measurement.
• The platform enables rapid clinical diagnostics for infectious diseases through sensitive thermal analysis.
• This modular microcalorimeter design represents a new paradigm in calorimetric applications and diagnostics.