(252b) Inexpensive Electrokinetic Microfluidic Systems Using Printed Circuit Board Substrates

Dielectrophoresis (DEP) is a well-known particle manipulation technique that has been able to capture, sort, concentrate, and characterize a variety of biological and artificial particles down to nanometers in diameter. Within the past decade there has been a thrust in developing novel DEP microsystems with the goals of higher throughput, inexpensive fabrication, and user-friendliness. Recent DEP techniques have developed fabrication methods to incorporate 3D electrodes or structures for improved throughput; however, clean room facilities and equipment are needed in order to create these platforms, limiting the number of researchers and students exposed to such technology.

This work shows preliminary results of fabricating 3D DEP microfluidic systems using neither clean room facilities nor photolithography. Rather, fabrication uses a CNC milling machine equipped with a sub-millimeter end mill. A copper-clad board provides the substrate for the system. Milled features serve as the microfluidic network with the copper electrodes being the sidewalls of the channels. The procedure of milling copper-clad boards is well known by the printed circuit board (PCB) industry and hobbyists. In addition, sub-millimeter end mills are commercially available for under $50 including 25, 50, and 100 micrometers. Preliminary results demonstrate this concept, aggregating 8 micrometer beads at 10 V using 3D quadropole electrodes milled with a 100 micrometer bit.