Microfluidic

An integrated micro/nano-fluidic system is presented for protein analysis. It is comprised of an integrated micromixer (IMM) and a preconcentrator with a separation column. The passive and planar type of IMM is based on an unbalanced split and the cross collision of the fluidic streams. The IMM can be easily fabricated and integrated to the microfluidic system. The preconcentrator has nanochannels formed by the electrical breakdown of polydimethylsiloxane (PDMS) membrane by applying a high electrical shock, but without any nano-lithography. The integrated microdevice was used for sample preparation (mixing with tagging molecules) and subsequent concentration of proteins. Proteins were electrokinetically trapped near the junction of the micro/nanochannels. We show a conceptual design and a simple microfluidic system for purposes of mixing and preconcentration. Figure Mixing and preconcentration of dissolved proteins using an integrated micro/nano-fluidic system

Today most of the countries facing many environmental problems out of which water pollution are extremely hazards and world's most of the countries facing enormous challenges to solve this. Water pollution due to Heavy Metal Ions (HMIs) is a global issue which requires proper attention to maintain the water quality demands. A portable system made of MEMS sensors capable of detecting multiple analytes simultaneously is highly demanded. The HMI detection in vapour phase can be a solution for laboratory based detection, but for the field instrument using MEMS the temperature cannot be raised beyond certain limit. Hence, the microfluidic detection is the only option which required high sensitivity. Accordingly, our main objective is to develop a microfluidic platform that can be used for sensing HMIs using a capacitive microcantilever beam fabricated by using MEMS technology. The proposed system is divided into two parts; the first one includes microfluidic chamber or tub and polydimethylsiloxane (PDMS) based microfluidic channel for handling water and second one uses the array of microcantilever beams surface modified with different protein for selective detection of HMIs. In this work, we try to investigate the cantilever based capacitive sensor for different pressure due to HMIs and sensitivity enhancement. Sensitivity optimization is very much essential and it is improved by using different shape, stress concentration region (SCR) and changing the dimension of microcantilever for HMI detection in water environment. It is found that in case of rectangular beam with SCR improves deflection up to 33% and in case of triangular beam this improvement is up to 73%.

This article reviews the recent development in microfluidics for medical diagnostics and integrations with biosensors. Diagnostic and sensing applications have been the focus of much of the development of the micro-Total-Analysis-Systems (MicroTAS), and have recently enjoyed further development in new fabrication technologies, integrations, and utilities in field- and medical-applications. The challenges for these applications have been to reduce cost, to meet the sensitivity requirements while providing throughput and speed, and to expand the repertoire of applications. This review focuses mostly on new developments in the last 5–10 years in materials development, chip architecture and integration, different sensing modes that can be used in conjunction with microfluidics, and new applications that have emerged or have been demonstrated; it also aims to point out where future research can be directed to in these areas.

We report the results of a comparative study of microfluidic emulsification of liquids with different viscosities. Depending on the properties of the fluids and their rates of flow, emulsification occurred in the dripping and jetting regimes. We studied the characteristic features and typical dependence of the size and of the size distribution of droplets in each regime. For each liquid, we identified a range of hydrodynamic conditions promoting generation of highly monodisperse droplets. Viscosity played an important role in emulsification: highly viscous liquids were emulsified into larger droplets with lower polydispersity. Although it was not possible to provide a unified scaling for the volumes of the droplets, our results suggest that the break-up dynamics of the lower viscosity fluids resembles the rate-of-flow-controlled break-up, as reported earlier for the formation of bubbles in flow-focusing geometries [Garstecki P, Stone HA, Whitesides GM (2005) Phys Rev Lett 94:164501]. The results of this study can be helpful for a rationalized selection of liquids for the controlled formation of droplets with a predetermined size and with a narrow distribution of sizes.

MEMS, Electromagnetic field is a way to manipulate droplets, beads or cells without direct contact. In particular, dielectrophoresis is often used in BioMEMS applications, for cell handling operations such as moving, sorting, trapping or deforming cells. In this paper, a 3D focusing geometry for the electrical field is proposed, that permit the trapping of single cell, or cells pair, thanks to positive dielectrophoresis. The design is explained with highlighting the focusing effect versus insulator shape for trapping cells. A prototype based on classical MEMS process and results of first trapping are presented.

This review describes recently emerging optical and microfluidic technologies suitable for point-of-care genetic analysis systems. Such systems must rapidly detect hundreds of mutations from biological samples with low DNA concentration. We review optical technologies delivering multiplex sensitivity and compatible with lab-on-chip integration for both tagged and non-tagged optical detection, identifying significant source and detector technology emerging from telecommunications technology. We highlight the potential for improved hybridization efficiency through careful microfluidic design and outline some novel enhancement approaches using target molecule confinement. Optimization of fluidic parameters such as flow rate, channel height and time facilitates enhanced hybridization efficiency and consequently detection performance as compared with conventional assay formats (e.g. microwell plates). We highlight lab-on-chip implementations with integrated microfluidic control for &quot...

Rapid chiral method development using microfluidic multiparallel HPLC is illustrated with several examples of ‘real world’ pharmaceutical intermediates for which speed was critical for successful process development. It is shown that this rapid chiral method development approach is suitable for support of high throughput screening of enantioselective catalytic hydrogenation reactions and other high throughput experimentation initiatives in pharmaceutical process research.

Abstract Today most of the countries facing many environmental problems out of which water pollution are extremely hazards and world’s most of the countries facing enormous challenges to solve this. Water pollution due to Heavy Metal Ions (HMIs) is a global issue which requires proper attention to maintain the water quality demands. A portable system made of MEMS sensors capable of detecting multiple analytes simultaneously is highly demanded. The HMI detection in vapour phase can be a solution for laboratory based detection, but for the field instrument using MEMS the temperature cannot be raised beyond certain limit. Hence, the microfluidic detection is the only option which required high sensitivity. Accordingly, our main objective is to develop a microfluidic platform that can be used for sensing HMIs using a capacitive microcantilever beam fabricated by using MEMS technology. The proposed system is divided into two parts; the first one includes microfluidic chamber or tub and polydimethylsiloxane (PDMS) based microfluidic channel for handling water and second one uses the array of microcantilever beams surface modified with different protein for selective detection of HMIs. In this work, we try to investigate the cantilever based capacitive sensor for different pressure due to HMIs and sensitivity enhancement. Sensitivity optimization is very much essential and it is improved by using different shape, stress concentration region (SCR) and changing the dimension of microcantilever for HMI detection in water environment. It is found that in case of rectangular beam with SCR improves deflection up to 33% and in case of triangular beam this improvement is up to 73%.