Design and Fabrication of Microelectrodes for Dielectrophoresis and Electroosmosis in Microsystems for Bio-Applications.

Microfluidic technology has emerged as a multidisciplinary field, integrating fluid dynamics, electronics, materials science, etc., enabling precise manipulation of small volumes of fluids and particles for various bio-applications. Among the forms of energy integrated into microfluidic systems, electric fields are particularly advantageous for achieving precise control at the microscale. This review focuses on the design and fabrication of microelectrodes that drive electrokinetic phenomena, dielectrophoresis (DEP) and electroosmotic flow (EOF), key techniques for particle and fluid manipulation in microfluidic devices. DEP relies on non-uniform electric fields to manipulate particles based on their dielectric properties, while EOF utilizes uniform electric fields to generate consistent fluid flow across microchannels. Advances in microelectrode fabrication, including photolithography, soft lithography, and emerging non-cleanroom techniques, are discussed. Additionally, the review explores innovative approaches such as rapid prototyping, contactless electrodes, and three-dimensional structures, along with material considerations like conductive polymers and carbon composites. The review discusses the role of microelectrodes in enhancing device functionality, scalability, and reliability. The paper also identifies challenges, including the need for improved fabrication reproducibility and multifunctional integration. Finally, potential future research directions are proposed to further optimize DEP- and EOF-based microsystems for advanced biomedical and diagnostic applications.