As the energy demands continue to swell with growing population and there persists a lack of unexploited oilfields, the prime focus of any nation would be to maximize the oil recovery factor from existing oil fields. CO2-Enhanced oil recovery is a process to improve the recovery of crude oil from an oil field and works at high pressure and in very deep conditions. CO2 and oil are miscible at high pressure, resulting in low viscosity and oil swells. This swelling can be measured based on mathematical calculations in real time and correlated with the CO2 concentration. This process has myriad advantages over its counterparts which include being able to harness oil trapped in reservoirs besides being cheaper and more efficient. A Diffusivity meter is inevitable in the measurement of the diffusion co-efficient of two samples. Diffusivity meters currently available in the market are weighed down by disadvantages like the requirement of large samples for testing, high cost and complexity. This elicits the need for a Microfluidic based diffusivity meter capable of analyzing Nano-liter sample volumes besides being more precise and affordable. The scope of this work involves the design and development of a Microfluidic robust and inexpensive prototype diffusivity meter using a capillary tube and endorsing its performance by comparison of results with known diffusivity range and supervision of the results with an electronic microscope coupled to PC and Data Acquisition System. The prototype produced at the end of the work is expected to outweigh disadvantages in existing products in terms of sample size, efficiency and time saving.
Today, Polymerase Chain Reaction (PCR) based DNA amplification plays an indispensable role in the field of biomedical research. Its inherent ability to exponentially amplify sample DNA has proven useful for the identification of virulent pathogens like those causing Multiple Drug-Resistant Tuberculosis (MDR-TB). The intervention of Microfluidics technology has revolutionized the concept of PCR from being a laborious and time consuming process into one that is faster, easily portable and capable of being multifunctional. The Microfluidics based PCR outweighs its traditional counterpart in terms of flexibility of varying reaction rate, operation simplicity, need of a fraction of volume and capability of being integrated with other functional elements. The scope of the present work involves the development of a real-time continuous flow microfluidic device, fabricated by 3D printing-governed rapid prototyping method, eventually leading to an automated and robust platform to process multiple DNA samples for detection of MDRTB-associated mutations. The thermal gradient characteristic to the PCR process is produced using peltier units appropriate to the microfluidic environment fully monitored and controlled by a low cost controller driven by a Data Acquisition System. The process efficiency achieved in the microfluidic environment in terms of output per cycle is expected to be on par with the traditional PCR and capable of earning the additional advantages of being faster and minimizing the handling.
A novel integrated optical component useful for two-species detection, particle velocity measurement and cell-sorting in
lab-on-a-chip devices is described. The component consists of dual waveguides that can simultaneously deliver light of
two wavelengths to two fixed points in a microchannel. Labeled cells in the channel can be detected by laser-induced
fluorescence stimulated by either wavelength or their velocities determined by measuring the time between peaks in the
captured signals. The properties of the integrated optical component are determined by simulations and measurements
and the measurement of velocities of fluorescent particles in pressure-driven flows is demonstrated.
A new optical detection system for microfluidic lab-on-a-chip applications is described. The photomultiplier tube (PMT) system is controlled by LabVIEW and has output/primary current gains that are programmable from 104 to 107. Light is delivered to and from microfluidic systems by a custom launch-and-detect fiber probe fabricated from one-millimeter plastic optical fibers. The noise characteristics are descrbied and the detection of fluorescent 15μm polystyrene spheres is demonstrated. Using the measured static spatial response of the tip, the velocities of moving microparticles can be calculated from dynamic measurements of their fluorescence.
Developmental work in the fabrication of microsystems with integrated optics and fluidics is described. For application such as blood flow and blood cell deformability studies, microparticle identification and manipulation, and on-chip chemical analysis, microchannels and waveguides with inner dimensions in the range of 30 - 50 μm are required. Two integration strategies are described: laser-writing of channels and waveguides in UV-curable polymers and fabrication of silver ion-exchange waveguides in glass microchannel biochips. A fiber-fed photomultiple detection system is also discussed.
The development of devices for biological and chemical analysis is a new and exciting application of micro-electro-mechanical systems (MEMS) technology. In this paper, a method for integrating multimode optical waveguides within glass biochips with fluidic microchannels is described. The waveguides buried in the glass are designed to carry probe light to the channels, capture any emission from samples therein, and deliver the emitted light it to a sensitive photodetector. The ultimate goal is a self-contained, operatorless analysis system for mass testing of biological samples. The field-assisted silver ion-exchange process for fabricating the multimode waveguides and some preliminary results on the waveguide properties are described.