Microfluidics and Sensors for DNA Analysis

Microfluidics drives the advance technology to perform biological and chemical experiments at micro and nanometer scale, at affordable cost with minimal material consumption and optimal results. In microfluidic devices fluidic components are miniaturized and integrated together, leading to a realization of an entire “lab on a chip,” in the same way that a microelectronic circuit is a whole computer on a chip [1]. There has been keen interest in achieving the full potential of this approach and, consequently, the development of many microfluidic devices and fabrication methods. Elastomeric materials such as polydimethylsiloxane (PDMS) have excellent alternatives to the silicon and glass used in new devices fabricated by MEMS (microelectromechanical systems) processes. Simplified device fabrication and the possibility of incorporating densely integrated microvalves into designs have helped microfluidics to expand into a ubiquitous technology that has found applications in many diverse fields.

Microfluidics is the science and technology of systems that process or manipulate small (10-9 to 10-6 liters) amounts of fluids, using channels with dimensions less than tens to hundreds of micrometers. Applications of microfluidic technologies offer many useful capabilities: the ability to use minuscule quantities of samples and reagents and to carry out separations and detections with high resolution and sensitivity; low cost; short times for analysis; and small footprints for the analytical devices [2]. Microfluidics exploits its most prominent characteristic, small size and less distinct characteristics of fluids in microchannels. It offers new capabilities in the control of concentrations of molecules in space and time. Microfluidics is a key to advancing molecular sensor based on bioassays including immunoassay, cell separation, DNA amplification and analysis [2]. It processes a vast number of parallel experiments rapidly with the tiny amount of reagents and chemicals. A reduction in size to the micrometer scale will usually not change the nature of molecular reactions, but laws of scale for surface per volume, molecular diffusion, and heat transport enable dramatic increases in throughput. The research for drugs demands robust and fast methods to find, refine and test a likely drug with relatively low cost. The discovery of a unique molecule with new qualities out of a nearly unlimited number of possibilities is laborious, time-consuming and relies heavily on technological resources that are available for handling small liquid volumes, automation, and high-through-put processing and analysis [1]. Initially, the concept of microfluidics solely dedicated to significantly reducing sample consumption and increasing efficiency in separation methods such as electrophoresis, but eventually low costs of mass production of microchips and automation of reaction systems for commercial use. At the time of review, there are many commercially available microfluidic devices made by prominent companies like Agilent Technologies, Evotec Technologies, Hitachi, and Fluidigm Technology [2].