Beyond two dimensions: Exploring 3D dielectrophoresis for microparticle control using carbon electrodes.

This study explores the frontiers of microparticle manipulation by introducing an actuator platform for the three-dimensional positioning of microparticles using dielectrophoresis (DEP), a technique known for its selectivity and ease of integration with microtechnology. Leveraging advancements in carbon-based devices due to their biocompatibility and electrochemical stability, our work extends the application of DEP from two-dimensional constraints to precise 3D positioning within microvolumes, employing a photolithography-based fabrication process known as Carbon-MEMS technology (C-MEMS). We present the design, finite element simulation, fabrication, and testing of this platform, which utilizes a unique combination of planar and 3D carbon microelectrodes individually addressable on a transparent substrate. This setup enables the application of DEP forces, allowing for high-throughput manipulation of multiple microparticles simultaneously, as well as displacement of individual microparticles in any desired direction. Demonstrated with spherical 1μm and 10μm diameter polystyrene microparticles, this platform features straightforward fabrication and is suitable for batch industrial production. The study concludes with a discussion of the platform's advantages and limitations, marking a significant step toward a valuable tool for studying complex biological systems.