Exploration of microfluidic technologies in cell study

In the past twenty years, microfluidics and micrometer-scale total analysis systems (μTAS) have been experienced a fast development and brought us a new insight to many fields, such as chemical and biological-analysis, chemical synthesis, and biomedical sciences. They take the advantages of downscaling laws to achieve better performances, such as high resolution and sensitivity of separation and detection; low cost and consumption of samples and reagents; shorter reaction times and faster heat transfer for analysis; and adaption of automation for commercial uses. However, this field is in its early adolescence, and still requires a broad range of microfabrication technologies, microcomponents, and their integration to complete functional systems. Throughout my studies, I have focused on Microfabrication technologies and its practical applications in cell biology. My work can be divided into three parts. Firstly, I developed a convenient method for fabricating functional whole-Teflon microchips by a series of fabrication techniques, including hot embossing micropatterns, sealing whole-Teflon chips, and integrating microvalves and pumps. Moreover, we further evaluate the performance of the Teflon chips by examining their compatibility with various solvents, biomolecules, and cell cultures. In the second part, I design a portable microchip integrated with screw-actuated microvalves to generate stepwise concentration gradient of anticancer drugs and provides a static culture environment to cells, which can be used for high-throughput drug screening on single cell level. Besides, I further developed several methods for cell micropatterning: (1) We used a NOA penetrated membrane as a mask for selective surface plasma treatment of the PEG-modified PDMS, which can further induce the cell micropattens in single cell level; (2)We also developed a micro-eraser micropatterning method by a stamping-seeding process, which is efficient in real-time multi-cell patterning on a single substrate; (3) Based on micro-eraser method, I further involved in a 3D substrate for generate single cell micropatterning with the capability of selecting, tracing, and analyzing single cell colonies in the long run