In-situ nanostructure synthesis and integration for advanced microfluidic systems

Abstract

In this master’s thesis, we introduce a novel integration method for the functional nanostructures within microfluidic channel by in-situ nanomaterial synthesis for the advanced microfluidic systems. Nanostructures integrated within microfluidic devices have great potentials for substantial improvement of performance and widening of applications by taking advantages of unique nanoscale material properties such as high chemical reactivity, electrical sensitivity, and mechanical robustness. However, the integration of nanostructures such as nanowires and nanotubes has been carried out by sequential multi-step procedures: ex-situ high-temperature synthesis of nanostructures followed by the assembly with microfluidic that requires complicated alignment processes. In this work, we report an extremely simple and controllable route to the fabrication of nanowires, in particular ZnO nanowires, within pre-fabricated microfluidic channel by liquid-phase synthesis. Since ZnO nanowires can be synthesized in low-temperature liquid environment, they can be easily grown within both silicon/glass-based and polymer-based microfluidic devices. In this dissertation, we will first describe our work on the global synthesis within the entire fluidic channel. Then, we will present local synthesis of nanowires either by seed patterning or by localized heating with microheaters in microfluidic channel. Finally, we will demonstrate the applications of in-situ synthesized nanowire arrays to chemical sensor, cell stimulation tool, particle trapping structure, and chaotic fluid mixer.