A miniaturized electrokinetic bioparticle microseparator based on travelling wave dielectrophoresis for lab on a chip applications

In order to offer the ability of smaller volumes and high throughput in Lab-On-a-Chip devices more miniaturized components are needed. In this paper a microchannel technique based on surface micromachining method is modified to a miniaturized microseparator. Any downscaling of channels which is used microfluidic components in such systems intensified the phenomena. The proposed device is a 4-phase travelling wave microseparator with fishbone-like and sorting electrodes. Due to fabrication process the electrodes made of highly boron-doped poly-silicon are covered by a thin insulating (silicon-nitride) layer. Additional advantage of the silicon-nitride layer on electrode arrays is the reduction of high electric field gradient. The effect of this layer on functionality of the microseparator is discussed. The simulation results show that a good focusing and separation occurs in the frequency range of 5MHz and 150kHz respectively, when electrical conductivity of buffer fluid is near 10µs/m. The fabrication steps are presented and influence of buffer fluid conductivity on the functionality of separator is presented.