Fabrication of a Polymeric Microfluidic Device with Inkjet-Printed Silver Electrodes for Electrokinetic Bioparticle Characterization

We are developing an inkjet printing technique for patterning electrodes on polymeric substrates to create microfluidic devices for bioparticle applications. Electrode deposition is important for actuating electrokinetic phenomena in microfluidic devices, and polymeric substrates are becoming increasingly common. Dielectrophoretic (DEP) forces are induced via application of a spatially non-uniform electric field and are directly dependent on the sign and magnitude of the ClausiusMossotti factor. Accurate characterization of particle response when subject to spatially varying electric fields is essential for successful implementation of DEP-based particle sorting and manipulation techniques. We propose a microfluidic device that will (a) characterize Clausius-Mossotti factors for biologically relevant particles and media, and (b) allow for easy and inexpensive fabrication outside of a clean room environment. Particle characterization is conducted using an interdigitated electrode design in a polymeric microchannel. A Dimatix inkjet printer is used to deposit micro-scale electrodes onto Zeonor 1020R using a silver nano-ink (PChem Assoc.). Electrode resolutions of approximately 70 μm have been accomplished using these techniques, which are compatible with applications on a biological scale. The inkjetting protocols developed allow for fast, inexpensive fabrication of our device and rapid prototyping for future research.