An Integrated Microfluidic Platform for Chemical and Biological Sensing Employing Polymer-coated Piezoelectric Microcantilevers

Microfluidic integrated systems offer several advantages compared to macroscopic techniques. The ability to handle small sample volumes, portability, and the low cost of the devices are the most significant of these advantages. Microfluidic systems have substantially advanced the landscape of chemical and biological research. Microfluidic platforms hold great promise in manipulation and examination of single cells, single molecules, sensor integration, chemical synthesis, biochemical assays, bioanalysis, and high-throughput screening. In addition, microfluidic systems have great potential for integration of Micro/Nano electromechanical systems (MEMS/NEMS) and microcantilever-based sensors.;In this work, an integrated microfluidic system with shear-protective regions that enables cell and particle immobilization, sensor integration, and nanoparticle synthesis is presented. Thus, a novel and simple microfluidic device for capturing small volume of cells by using sidewall microgroove containing channels and microposts is developed. The developed microfluidic system enabled the control of fluid flow and shear stress profiles. Furthermore, the shear stress variation and cell positioning in the sidewall microgrooves were investigated. Moreover, the histograms of cell locations in the microgrooves were provided and the most probable destination of the cells was presented. In the microfluidic device, further investigation on extracting cell information from image data was carried out. Hence, a cell segmentation technique was developed for cell counting and extracting the cell information from the microfluidic device.;This platform also has the capability of integration of polymer coated piezoelectric microcantilevers which can be functionalized for analyte detection. Piezoelectric microcantilever-based sensors provide less complex system, eliminate the need for external optics and optical alignments, operate under larger gap distances, consume less power and generate less heat. Furthermore, piezoelectric microcantilever-based sensors can operate in the self-sensing manner where a piezoelectric layer embedded in the structure of the microcantilevers can be used for both sensing and actuating purposes. Moreover, an excellent way of enhancing and broadening the applicability and functionality of piezoelectric microcantilever-based sensors is to coat them with a layer of sensitive polymer. The data obtained from analyte detection by polymer coated piezoelectric microcantilever was presented. In addition, through a combined mathematical modeling the experimental findings were rationalized. Integration of microfluidic platform containing polymer coated piezoelectric microcantilever was presented. Utilization of three-dimensional (3D) printing method for developing of the microfluidic component of integrated system was discussed. Alternative physical set-up of the integrated microfluidic platform containing microcantilever array was presented.;Microfluidic devices are also able to rapidly mix reagents, and provide homogenous reaction environments. These features make them an ideal platform for nanoparticle synthesis. In this work, capability of nanoparticle synthesis by our microfluidic platform was also presented. In particular, flow focusing microfluidic technique for continuous synthesis of nanoparticles was examined.;There are some improvements that can be pursued for further investigation on the presented integrated platform such as using different shapes and angles of sidewall microgrooves. Overall, it is possible to use this simple and adaptable platform for a sensitive detection of a wide range of analytes.