Over the past decade, interest in microfluidics has surged as applications have trended towards novel biological assays. Specifically, the ability of microfluidics to parallelize cellular studies through array-based chip designs has attracted researchers interested in investigating cellular function under a wide variety of environmental conditions. The capability of microfluidic devices to control microenvironment conditions and induce dynamic perturbation to cellular systems makes microfluidics (or "lab-on-a-chip") an attractive platform to study gene expression dynamics. In this project, the functionality of microfluidic technology is exploited to design and construct a device for isolation and observation of cells in high throughput. The integration of a concentration gradient with homogenous medium within each chamber was designed specifically to investigate gene regulation in Saccharomyces cerevisiae under various concentrations of chemical inducers. These devices were designed to sustain cells for extended periods of time with high temporal resolution to study dynamic gene expression in single cells. The device builds on previous studies by probing up to eight distinct cell cultures in parallel. The microfluidic platform was then used to study yeast cells at various levels of inducer perturbations. Further experimentation revealed the utility of a parallel gradient by producing an induction curve of the yeast response. Such high-throughput designs will prove essential to yeast systems biology research as it strives to understand the complex regulatory interactions that dictate cell function by probing vast regions of parameter space.

The central idea/premise behind Ancestral Meridians is that there are undiscovered acupuncture points that could lead mankind to higher spiritual and emotional planes. Ancestral Meridians is designed to explore the possibility that these points may exist. It should be clearly understood that acupuncture is not the sole instrument used to explore the undiscovered but may create the conduit for a flow of information from an area, or areas, previously unknown. Ancestral Meridians is a modern novel divided into three main story lines, with linking substories woven into and throughout the narrative. The action of the work takes place in America, Ancient Egypt, India, and modern-day China. The stories in Ancestral Meridians are revealed by Dr. Daniel Lane II and Dr. Jonathan Hoover, both acupuncturists.

Droplet-based microfluidics has been considered as a prospective tool for high throughput screening analysis, which is highly demanded in a wide range of areas including but not limited to life science research, drug discovery, material synthesis and environmental monitoring. Low sample consumption, reduced reaction time, high throughput manipulation, fast mixing, and prevention of cross contamination at channel walls are just some of the benefits of droplet-based microfluidics. Although extensive research efforts have been reported in the study of droplet-based microfluidics over the past decades, it has yet to be widely commercialized. One of the challenges that limit droplet microfluidic chips from being commercialized is the difficulty in integrating multiple functions robustly without increasing the device footprint. Major functionalities of interest include generating droplets with controlled volume and frequency, and precisely controlling and manipulating each individual droplet such as sorting, detecting, merging, splitting, pairing, mixing, trapping, releasing, long term and short term storing, etc. Since many of these functionalities rely on the accuracy of droplet generation which is the first step, it is crucial to investigate the droplet formation process and understand how to design microfluidic structures to manipulate each individual droplet effectively. To this end, this thesis started with a fundamental study of droplet generation in a flow focusing geometry based on extensive experimental data, from which a physical model was developed to describe droplet formation processes, then move on to study droplet generation in a geometry with two junctions in series, with the goal of improving single encapsulation (one particle per droplet) efficiency. Later, droplet merging towards whole genome amplification and drug screening applications was investigated, and finally a microfluidic chip integrated with multiple functionalities was developed, and its robustness was validated. The first project studied the fundamental principles of liquid-liquid droplet generation in a flow focusing device. This work presents a 3D physical model with less fitting parameters than existing ones. The model describes droplet formation process in flow focusing devices operating in the squeezing regime, where droplet size is usually larger than the channel width, and was developed based on a systematic and extensive experimental study. In particular, it incorporates an accurate geometric description of the 3D droplet shape during the formation process, an estimation of the time period for the formation cycle based on the conservation of mass, and a semi-analytical model predicting the pressure drop over the 3D corner gutter between the droplet curvature and channel walls, which allows droplet size, spacing and formation frequency to be determined accurately. The model takes into account change in channel geometry (height to width ratio), viscosity contrast, flow rate ratio and capillary number with a wide variety. In the second project, liquid-liquid droplet generation in a flow focusing device with two junctions in series was investigated using experimental approach. Extra emphasis was placed on the device's ability to encapsulate single cell and particle. . This study employs glycerol solutions with different concentrations as the dispersed phase, which tends to form stratified flow at the first junction due to viscosity contrast. The stratified flow proceeds to form droplets in oil stream at the second junction. To obtain a comprehensive understanding of the droplet formation dynamics involving stratified flow, five different scenarios were considered. These include a single stream of 10%glycerol aqueous solution, a single stream of 80%glycerol aqueous solution, as well as the simultaneous flow of multiple streams of the above mentioned solution. Droplet size and formation period for these cases were compared and analyzed considering the same geometric and flow conditions. It is found that stratified flow structure strongly influences droplet formation dynamics such as droplet size and formation frequency and the scenario with 80%glyc surrounded by 10%glyc in the first junction generates the largest droplet size. Each structure finds its own applications. For the purpose of single encapsulation, the scenario with 80%glyc surrounded by 10%glyc in the first junction is most suitable because the high viscosity of 80%glyc allows particles to be focused into a thin stream and spaced out before entering droplets. On the other hand, the scenario with two fluids side by side in the first junction generates droplets with high monodispersity for a larger range of flow ratios, which is useful for high throughput reactions involving different reagents. After understanding the fundamentals of the droplet generation process, several designs for practical use were proposed to generate or manipulate droplets. These designs include: i) a flow focusing device that improve droplet size uniformity through changing junction angle; ii) a system for droplet generation on demand, which is essential to controlling droplets of specific reagents; iii) a geometry for generating droplet pairs with uniform droplet sizes and controlled droplet spacing , and to study the interaction between two nearby droplets; iv) a simple droplet merging chamber for controlled reagent volume; and v) a droplet trapping and releasing on demand system for drug screening. The final part of this thesis presents a complex microfluidic system that integrates multiple functionalities, including droplet generation, pairing, trapping, merging, mixing, and releasing. The criterion of this design was analyzed and verified by experiments. This design does not require any synchronization of droplet frequency, spacing or velocity, which makes the microfluidic chip work robustly, and is controlled entirely by liquid flow eliminating the needs for electrodes, magnets or any other moving parts. This design can be applied to many chemical or biological reactions, such as drug screening, chemical synthesis, and cell culture, etc.

Microfluidic Devices for Biomedical Applications, Second Edition provides updated coverage on the fundamentals of microfluidics, while also exploring a wide range of medical applications. Chapters review materials and methods, microfluidic actuation mechanisms, recent research on droplet microfluidics, applications in drug discovery and controlled-delivery, including micro needles, consider applications of microfluidic devices in cellular analysis and manipulation, tissue engineering and their role in developing tissue scaffolds, and cover the applications of microfluidic devices in diagnostic sensing, including genetic analysis, low-cost bioassays, viral detection, and radio chemical synthesis. This book is an essential reference for medical device manufacturers, scientists and researchers concerned with microfluidics in the field of biomedical applications and life-science industries. - Discusses the fundamentals of microfluidics or lab-on-a-chip (LOC) and explores a wide range of medical applications - Considers materials and methods for microfabrication, microfluidic actuation mechanisms and digital microfluidic technologies - Details applications of microfluidic devices in cellular analysis and manipulation, tissue engineering and its role in developing tissue scaffolds, and stem cell engineering

The field of microfluidics has in the last decade permeated many disciplines, from physics to biology and chemistry, and from bioengineering to medical research. One of the most important applications of lab-on-a-chip devices in medicine and related disciplines is disease diagnostics, which involves steps from biological sample/analyte loading to storage, detection, and analysis. The chapters collected in this book detail recent advances in these processes using microfluidic devices and systems. The reviews of portable devices for diagnostic purposes are likely to evoke interest and raise new research questions in interdisciplinary fields (e.g., efficient MEMS/microfluidic engineering driven by biological and medical applications).The variety of the selected topics (general relevance of microfluidics in medical and bioengineering research, fabrication, advances in on-chip sample detection and analysis, and specific disease models) ensures that each of them can be viewed in the larger context of microfluidic-mediated diagnostics.

Microfluidics for Biological Applications provides researchers and scientists in the biotechnology, pharmaceutical, and life science industries with an introduction to the basics of microfluidics and also discusses how to link these technologies to various biological applications at the industrial and academic level. Readers will gain insight into a wide variety of biological applications for microfluidics. The material presented here is divided into four parts, Part I gives perspective on the history and development of microfluidic technologies, Part II presents overviews on how microfluidic systems have been used to study and manipulate specific classes of components, Part III focuses on specific biological applications of microfluidics: biodefense, diagnostics, high throughput screening, and tissue engineering and finally Part IV concludes with a discussion of emerging trends in the microfluidics field and the current challenges to the growth and continuing success of the field.