Monolithic surface micromachined fluidic devices for dielectrophoretic preconcentration and routing of particles

• Published in: Journal of micromechanics and microengineering 2006-10, Vol.16 (10), p.1909-1918
• Main Authors: James, Conrad D, Okandan, Murat, Mani, Seethambal S, Galambos, Paul C, Shul, Randy
• Format: Article
• Language: English
• Subjects: Applied fluid mechanics; Applied sciences; Electronics; Exact sciences and technology; Fluid dynamics; Fluidics; Fundamental areas of phenomenology (including applications); Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Mechanical engineering. Machine design; Mechanical instruments, equipment and techniques; Microelectronic fabrication (materials and surfaces technology); Micromechanical devices and systems; Physics; Precision engineering, watch making; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices
• ISSN: 0960-1317; 1361-6439
• DOI: 10.1088/0960-1317/16/10/001

We describe a batch fabrication process for producing encapsulated monolithic microfluidic structures. The process relies on sacrificial layers of silicon oxide to produce surface micromachined fluid channels. Bulk micromachined interconnects provide an interface between the microchannels and meso-scale fluidics. The full integration of the fabrication processing significantly increases device reproducibility and reduces long-term costs. The design and fabrication of dielectrophoresis (DEP) gating structures configured in both batch-flow and continuous-flow modes are detailed. Highly efficient microparticle preconcentration (up to ~100X in 100 s) and valving (97% particle routing efficiency) are demonstrated using ac DEP and an accompanying phase separation. The low aspect-ratio fluid channels with integrated microelectrodes are well suited for mum and sub-mum particle manipulation with electric fields.