Lab-on-a-chip technology is enabling revolutionary influences on biochemistry and presents a whole new class of miniaturized analysis systems for chemical and biological applications. Biomolecular analysis is one of the most promising applications for such lab-on-a-chip micro/nanofluidic systems. The ability to analyze biologically-relevant entities on chip, such as DNA and proteins, offers great potential to outperform conventional clinical diagnostic techniques through many opportunities including economy of samples and reagents, less reaction waste, short analysis time, cost effectiveness, high resolving power of separation, compactness and portability, high throughput, and the ability to multiplex and automate. The glass capillaries or channels, as the basic elements of mic...[ Read more ]

Lab-on-a-chip technology is enabling revolutionary influences on biochemistry and presents a whole new class of miniaturized analysis systems for chemical and biological applications. Biomolecular analysis is one of the most promising applications for such lab-on-a-chip micro/nanofluidic systems. The ability to analyze biologically-relevant entities on chip, such as DNA and proteins, offers great potential to outperform conventional clinical diagnostic techniques through many opportunities including economy of samples and reagents, less reaction waste, short analysis time, cost effectiveness, high resolving power of separation, compactness and portability, high throughput, and the ability to multiplex and automate. The glass capillaries or channels, as the basic elements of microchemical “laboratories” in micro/nanofluidic systems, are fabricated with various surface properties, dimensions and structures to meet the requirements and provide adequate environments of biomolecule transport, enrichment, separation and detection.

In this thesis, we propose two novel micromachined platforms involving cylindrical glass micro/nanocapillaries to serve crucial roles in the various stages of biomolecular analysis. One platform is microchannel plate (MCP), which involves a high-porosity glass membrane with millions of high-aspect ratio identical capillaries that are closely packed through glass fiber drawing process. The second platform involves self-enclosed cylindrical glass capillaries monolithically integrated on silicon through a lithography-based process in plane with rectangular microchannels. The round capillaries are achieved through thermal reflow of a glass layer in microstructured trenches where slender voids are molded into cylindrical tubes. The utility of these platforms for transport, enrichment, separation and detection of biomolecules is explored and demonstrated. Leveraging on these platforms, a number of novel devices are implemented here and present notable progress beyond the existing state of the art, addressing particular issues in bioanalysis stages such as biomolecule enrichment, high performance chip-based capillary electrophoresis and liquid chromatography separation, and detection.