Microfluidic impedance flow cytometry (μIFC) and digital microfluidics (DMF) are powerful techniques for single cell analysis and point-of-care diagnostics. Conventionally, these platforms are fabricated in cleanrooms with complicated and time-consuming microfabrication procedures such optical lithography, depositions, and etching. However, such high-end microfabrication facilities are extremely difficult to establish in low-income and developing countries due to their high capital investment and operating costs. This prevents the fabrication and use of these platforms in the developing world, where they are most needed for point-of-care applications. This thesis addresses these challenges by developing low-cost, scalable, easily-fabricable, and inkjet printed μIFC and DMF platforms for point-of-care applications, especially in developing countries. Our platforms can be fabricated rapidly by any minimally trained user using just a commercial office inkjet printer, without the need for expensive cleanroom facilities.

In chapter 2, we present a high-throughput, low-cost, inkjet printed μIFC platform capable of measuring single cell electrical properties. By combining our platform with advanced machine learning techniques, we demonstrate its utility to reliably classify different cell types. Specifically, we show the utility of our platform to reliably discriminate between cancerous and non-cancerous cells and to identify and classify different cancer cell sub-types. Our results show the potential of our platform for single cancer cell analysis, point-of-care cancer diagnosis and tumor heterogeneity studies.

In chapter 3, we present our reusable, low-cost, easily-fabricable, inkjet printed DMF platform. We demonstrate the utility of our platform to precisely move and mix droplets of different reagents. We also show a miniaturized, portable, programmable, battery-powered version of our platform suitable for performing pre-programmed biochemical assays. Such a platform could be useful for performing point-of-care diagnostic tests in developing countries.

We envision our low-cost, scalable, easily fabricable and user-friendly μIFC and DMF platforms to be potential game-changers in single cell analysis and point-of-care diagnostic technologies.