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Dielectrophoresis is a force applied to microparticles in non-uniform electric field. The presented study discusses the fabrication of the glassy carbon interdigitated microelectrode arrays using lithography process based on lithographic patterning and subsequent pyrolysis of negative SU-8 photoresist. Resulting high resistance electrodes would have the regions of high electric field at the ends of microarray as demonstrated by simulation. The study demonstrates that combining the AC applied bias with the DC offset allows the user to separate sub-populations of microparticulates and control the propulsion of microparticles to the high field areas such as the ends of the electrode array. The direction of the movement of the particles can be switched by changing the offset. The demonstrated novel integrated DEP separation and propulsion can be applied to various fields including in-vitro diagnostics as well as to microassembly technologies. 

Microparticulates placed in non-uniform electric field experience dielectrophoretic forces that can be utilized for the guided assembly of microparts. The presented study discusses two types of such guided micro-assemblies. We observe the self-assembly of carbon nanotubes (CNTs) into the conductive bridges between microelectrodes along the field lines. These conductive bridges are later fixed in place by the layer of electrodeposited conductive polymer Polypyrrole (PPy). Additionally, we report on using positive dielectrophoresis (pDEP) to attract polymer microbeads to the windows opened in the SU-8 photoresist on top of the microelectrodes. The electric field is getting shielded by the photoresist and thus the beads are attracted only to the bare electrodes opened in the photoresist via standard lithographic process. Presented techniques open new possibilities for the guided assembly of micro-components for sensors, actuators, microelectromechanical systems (MEMs), as well as for micro- and nano-electronic devices.