Helical dielectrophoretic particle separator fabricated by conformal spindle printing

This paper reports the fabrication and testing of a helical cell separator that uses insulator-based dielectrophoresis as the driving force of its separation. The helical channel shape's main advantage is its constant curvature radius which generates a constant electric field gradient. The presented separator was fabricated by extruding a sacrificial ink on rotating spindles using a computer- controlled robot. After being assembled, connected to the reservoir and encapsulated in epoxy resin, the ink was removed to create a helical microchannel. The resulting device was tested by circulating polystyrene microbeads of 4 and 10 μm diameter through its channel using a voltage of 900 VDC. The particles were separated with efficiencies of 94.0% and 92.5%, respectively. However, roughness in some parts of the channel and connections that had larger diameters compared to the channel created local electric field gradients which, doubtless, hindered separation. It is a promising device that could lead the way toward portable and affordable medical devices.