Fluid Patterning in a Cavity Array for High-Throughput Screening and Biotechnological Applications

Abstract

Over the past few decades, fundamental biological understanding has advanced significantly with the help of experimental biotechnologies. Among them, synthetic biology as a rising research field has shown its capability for building new microorganisms from the scratch. In conjunction with synthetic biology, directed evolution techniques seem to be highly useful for industrial purposes such as the over-production of chemical products such as biofuels, which are expected to resolve global energy problems. However, it still requires a high-throughput screening technique and/or compartmentalized environments for cell sorting. In this thesis, two microfluidic technologies are described. First, a novel microdroplet trapping technology is developed that utilizes the difference of specific gravity between two immiscible fluids to offer simple and easy manipulation of microdroplets for time-traceable single microorganism analysis. Second, a high-throughput screening technology is developed by patterning fluid, in which individual Escherichia coli cells can be immobilized and cultured in a cavity array format. It is noted that the cavities were coated with parylene and bonded with another parylene layer to secure chemical compatibility. In addition, it was successfully demonstrated that the two technologies hold a high potential to enable not only high-throughput screening but also many biological experiments such as detection of cell-excreted products, long-term cell incubation, cell to cell communication, and detection of target molecules via a whole cell biosensor