Thermal Effects in Microfluidic Electrokinetic Flows: From Limitation to Design Opportunity

Area of Science:

• Fluid dynamics
• Heat transfer
• Microfluidics

Background:

• Microfluidic electrokinetic flows are vital for lab-on-a-chip diagnostics, microelectronics cooling, and biomedical sample manipulation.
• These systems involve complex heat transfer processes like Joule heating and flow instabilities, impacting device performance.
• Challenges include non-equilibrium charge dynamics, limited thermophysical data for complex fluids, and thermal crosstalk.

Purpose of the Study:

• To review the literature on heat transfer in microfluidic electrokinetic flows over the past 20 years.
• To cover fundamental mechanisms, characterization approaches, limitations, and opportunities.
• To provide design principles for thermally optimized microfluidic technologies.

Main Methods:

• Literature review of analytical, numerical, and experimental studies.
• Analysis of fundamental heat generation and dissipation mechanisms.
• Discussion of current challenges and future research directions.

Main Results:

• Summarizes key findings on Joule heating, flow instabilities, and thermal-fluid interactions.
• Identifies limitations in current understanding and data for complex fluids.
• Highlights application-driven opportunities and design considerations.

Conclusions:

• Effective thermal management is critical for robust electrokinetic microfluidic devices.
• Further research is needed to address non-equilibrium dynamics and data gaps.
• This review offers guidelines for developing advanced microfluidic technologies.