Abstract

Digital microfluidics (DMF) is a technique for the manipulation of discrete droplets on an array of electrodes, which allows the controlled movement of fluids and represents an alternative from the conventional microfluidic paradigm of transporting fluids in enclosed channels. One of the major benefits of DMF is that fluid motion and control is achieved without external pumps and fabricated valves – it only requires the use of electric fields. The automation component of DMF has pushed the barriers of this ‘lab-on-chip’ technology; however, integration with external components (i.e. world-to-chip) interfaces has been a challenge. For example, the delivering of the biological fluids to the chip and integrating temperature control on a single platform are considered as two world-to-chip challenges in DMF. To address these two challenges, my thesis describes two world-to-chip components that are integrated with the DMF device: reagent delivery and temperature control. This new platform enables us to perform a variety of biological or chemical experiments on a chip with reduced manual intervention. Specifically, the new platform enabled an increase in reservoir volume on the chip by 40-fold from ~10 µL to 400 µL which allowed more reproducible dispensing and eliminated the need to refill the reservoirs during the biological assay. In addition, we integrated a closed-loop temperature control system that enabled fast and rapid changes in temperature on the chip.
To show the utility of the world-to-chip interfaces, we validated the system by automating bacterial transformation and enzymatic assay procedures, which show that both procedures require world-to-chip interfaces for accurate and precise implementation. Overall, we propose that this system has the potential to be integrated for other types of biological assays and experiments which require fluidic control, automation, and temperature control.