Precise manipulation of microparticles and cells is crucial for advancements in diverse fields, from disease diagnostics to advanced materials engineering. Microfluidic devices offer a promising platform for such manipulation due to their low cost, high sensitivity, and minimal sample requirements. This book introduces a novel microfluidic device that leverages dielectrophoresis (DEP) - a label-free and highly efficient technique - for continuous separation of three distinct particle populations. Unlike existing DEP-based separators, this device utilizes a uniquely configured bi-gap electrode pair, enabling enhanced separation efficiency and purity. The book details the design, fabrication, and performance evaluation of this innovative device.