Inexpensive three-dimensional dielectrophoretic microfluidic devices using milled copperclad substrates

• Fabrication of microfluidic devices (without a clean room) using a printed circuit board milled with a 100 μm bit.
• Electrodes themselves serve as sidewalls of the microfluidic device.
• This inexpensive fabrication method enables higher throughput dielectrophoretic trapping and/or sorting.

This manuscript demonstrates an inexpensive method of fabricating 3D dielectrophoretic microfluidic devices using a milling machine equipped with a sub-millimeter end mill. Features were milled into a copperclad substrate, otherwise typically used for printed circuit boards. Milled electrodes themselves serve as walls of the microfluidic channel therefore delivering a stronger electric field throughout the depth of the microchannel compared to traditional, coplanar electrode designs. Dielectrophoretic particle trapping and concentration were demonstrated with 8 μm polystyrene beads at voltages no greater than 10 V. The method of fabrication will be discussed as well as advantages and challenges associated with this technique.