Adventures in using 3D Printing to Integrate Electrodes into Microfluidic Devices for Analysis of Cellular Systems

Our lab has long been interested in the development of robust microfluidic devices that integrate cell culture and analysis, with electrochemistry being used to detect neurotransmitters in close-to-real-time. This talk will describe new advances we have made using 3D printing technology to create microfluidic devices with integrated electrodes. First, the use of threaded electrodes on either side of a channel has been used to create an in-line microfluidic device with amperometric detection. This system can be integrated with a separate mode of detection downstream from the electrochemical flow cell by addition of a mixing T for introduction of reagents for chemiluminescent detection of ATP. This results in a single 3D-printed device that can be used for electrochemical and luminescence detection, nearly simultaneously. We will also describe methodology to fully integrate electrode materials into microfluidic devices during the print process. This approach uses a stacked printing process with liquid support to result in devices where electrodes and a capillary fluidic connection are directly integrated and ready to use when printing is complete. We have extended this process to enable integration of gold, platinum or carbon electrodes with 50 micron channels for microchip electrophoresis. The ability to use these microchip electrophoresis/electrochemistry devices with off-chip sampling methods such as microdialysis will be discussed. Finally, the use of 3D printing to create a fluidic transwell culture system with ports for TEER measurements will be described, with work towards a true blood-brain barrier mimic with actual blood flow.