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

Microfluidic electrokinetic flows play a central role in applications such as lab-on-a-chip diagnostics, microelectronics cooling, and biomedical sample manipulation. These systems involve intricate heat transfer processes, including Joule heating from ionic currents, temperature-driven flow instabilities, and strongly coupled thermal–fluid interactions, that crucially affect device performance, reliability, and scalability. Current challenges include non-equilibrium charge dynamics, incomplete thermophysical property data for complex fluids, and thermal crosstalk in integrated platforms. This review summarizes the fundamental mechanisms of heat generation and dissipation in electrokinetic micro-flows, describes analytical, numerical, and experimental approaches for characterizing thermal effects, and discusses application-driven opportunities and limitations. It also highlights open questions and future research directions and offers a comprehensive view of the unified principles and practical design guidelines for developing robust, thermally optimized electrokinetic microfluidic technologies.