Fabrication of dielectrophoretic microfluidic device

Abstract

Technological needs of the recent times require the improvement in micro-scale devices that manipulate the bioparticles like cells, bacteria, viruses, DNA, proteins, etc. Such devices have diverse and widespread applications in biomedical, drug delivery and diagnostics for separating, trapping, sorting and mixing of particles. Dielectrophoresis (DEP) is one of the techniques used for manipulating the particles in a nonuniform electric field. In the present study, fabrication and characterization of microfluidic device for DEP is analyzed and experimented. An overview of fabrication techniques which can be used for making of DEP device is provided with experimental details. DEP microfluidic device is fabricated by preparing channels and microelectrodes on PDMS and glass materials respectively. Oxygen plasma treatment has been used for bonding the PDMS channel and micro-electrode patterned glass substrate. Further experiments are conducted to demonstrate the DEP principle with polystyrene microbeads. The movement of microbeads towards the high electric field strengths at 12Vpp and 10 MHz frequency is observed. Characterizing equipments like ellipsometer, profilometer, scanning electron microscopy, contact angle measurement systems were used for measuring oxide layer thickness, width and depth of the channels, surface characteristics etc., during fabrication.