Temporal and spatial temperature measurement in insulator-based dielectrophoretic devices

Area of Science:

• Analytical Chemistry
• Biophysics
• Microfluidics

Background:

• Insulator-based dielectrophoresis (iDEP) is a microfluidic technique for manipulating biological samples.
• Joule heating in iDEP can cause detrimental effects like thermal flow and biomolecule degradation.
• Precise control of the microenvironment, including temperature, is crucial for iDEP applications.

Purpose of the Study:

• To investigate temperature variations in iDEP devices.
• To compare experimental temperature measurements with numerical simulations.
• To evaluate two different experimental methods for temperature measurement in iDEP.

Main Methods:

• Experimental temperature measurements using thermosensitive dye Rhodamine B.
• In-channel measurement and thin film measurement techniques were employed.
• Comparison of experimental data with numerical simulations of Joule heating effects.

Main Results:

• Minimal temperature increases were observed at conductivities of 100 and 300 μS/cm up to 3000 V.
• At 1 mS/cm and 3000 V, significant temperature increases occurred, indicating potential degradation risks.
• The thin film measurement method showed lower temperature enhancement and better agreement with simulations.

Conclusions:

• Temperature effects are marginal for iDEP of proteins and mitochondria at common buffer conductivities.
• Higher conductivities pose a risk of thermal degradation in iDEP devices.
• The thin film method is a preferable experimental approach for temperature monitoring in iDEP due to accuracy and material independence.