In microfabrication

Haab B B and Mathies R A 1999 Single-molecule detection of DNA separations in microfabricated capillary electrophoresis chips employing focused molecular streams Ana/. Chem. 71 5137-45... 

Ross D, Gaitan M, Locascio LE (2001) Temperature measurement in microfluidic systems using a temperature-dependent fluorescent dye. Anal Chem 73 4117-4123 Sammarco TS, Bums MA (1999) ThermocapiUary pumping of discrete drops in microfabricated analysis devices. AlChE J 45 350-366... 

Figure 4.7 Steps in microfabrication of the chip reactor with multiple vertical injections [17].

The flow distribution was far from ideal [23]. Collected volumes at the individual outlets ranged from 2.15 to 3.65 ml, thus, differing by more than 50% at maximum. This was seen to be due to differences in pressure drops resulting from imperfections in microfabrication. 

Lu, H., Schmidt, M. A., Jensen, K. F., Photochemical reactions and online product detection in microfabricated reactors, in Matlosz, M., Ehrfeld, W., Baselt, j. P. (Eds.), Microreaction Technology - IMRET 5 Proc. 5th International Conference on Microreaction Technology, pp. 175-184, Springer-Verlag, Berlin (2001). 

Salimi-Moosavi, H., Tang, X, Harrison, D. )., Electroosmotic pumping of organic solvents and reagents in microfabricated reactor chips,... 

In general, optical-based pH measurement techniques require relatively expensive and cumbersome instruments, and their sophisticated method cannot be easily carried out for routine assay. Interfering contact and reactions of the dye molecules, particularly considering in-vivo measurements, cannot be excluded [34], Some other possible factors, such as a weaker signal at shorter response times, complications in microfabrication, and difficulties in attaching the chemical or biological agents to the small fiber tip, are potential limitations for the application of these optical sensors to in-vivo measurements in micro environments [35]. 

Lu H, Schmidt MA, Jensen KF (2001) Photochemical Reactions and On-Line UV Detection in Microfabricated Reactors. Lab Chip 1 22-28 Manz A, Harrison DJ, Verpoorte EMJ, Fettinger JC, Ludi H, Widmer HM (1991) Miniaturization of Chemical-Analysis Systems - A Look into next Century Technology or just a Fashionable Craze. Chimia 45 103-105 McCreedy T (1999) Reducing the Risks of Synthesis. Chem Ind 15 588-590 McCreedy T (2000) Fabrication Techniques and Materials Commonly Used for the Production of Microreactors and Micro Total Analytical Systems. Trac Trends Anal Chem 19 396-401... 

In addition to providing a brief tutorial on 2PA spectroscopy, some of the examples discussed here can be useful in understanding the origin of the 2P activity and in estimating approximate 2PA cross sections of so-called conventional initiators which have been used by some investigators in microfabrication applications (see Sect. 5). 

A conceptually simple way of changing surface properties is to remove parts of it. These methods are summarized as etching techniques [407,444], In particular in microfabrication etching techniques are essential. Etching techniques are characterized by several properties ... 

Significant advances have occurred in microfabricated ion sensitive and Pd gated field effect devices and fiber optic, chemically rsnsitive elements. These elements are beginning to find their way into commercial development. Recent advances in these devices are discussed and compared. Pyroelectric sensor devices developed here are reviewed. A discussion of the utility of these devices is presented. 

Plastic materials have gained importance in microfabrication due to their ease of molding, inexpensiveness, and disposability. Some workers have used these substrates for fabrication of microchips. Pethig et al. [78] and Roberts et al. [79] used laser ablation as a direct method for creating microchannels in plastic chips without the need for fabrication. The methods used an UV excimer laser to bum the microchannels onto the polymer substrate, moving in a predefined,... 

Since it will take several years to realize such an integral software toolbox, individual approaches with separate steps have to be applied to meet gradually the requirements of microreactor design. Standard software for computational fluid dynamics is directly applicable in this context, and there are also powerful software tools for the simulation of special steps in microfabrication processes. However, there has been rather little experience with materials for microreactors, optimization of microreactor design, and, in particular, the treatment of interdependent effects. Consequently, a profound knowledge of the basic properties and phenomena of microreaction technology just described is absolutely essential for the successful design of microreaction devices. 

Surangalikar, H., Hydrocarbon hydrogenation and dehydrogenation reactions in microfabricated catalytic reactors, Chem. Eng. Sci. 2003, 58, 19-26. 

Microfabrication is increasingly central to modern science and technology. Many opportunities in technology derive from the ability to fabricate new types of microstructures or to reconstitute existing structures in down-sized versions. The most obvious examples are in microelectronics. Microstructures should also provide the opportunity to study basic scientific phenomena that occur at small dimensions one example is quantum confinement observed in nanostructures [1]. Although microfabrication has its basis in microelectronics and most research in microfabrication has been focused on microelectronic devices [2], applications in other areas are rapidly emerging. These include systems for microanalysis [3-6], micro-volume reactors [7,8], combinatorial synthesis [9], micro electromechanical systems (MEMS) [10, 11], and optical components [12-14]. 

Several techniques for miniaturization of simple chemical and medical analysis systems are described. Miniaturization of total analysis systems realizes a small sample volume, a fast response and reduction of reagents. These features are useful in chemical and medical analysis. During the last decade many micro flow control devices, as well as the micro chemical sensors fabricated by three dimensional microfabrication technologies based on photofabrication, termed micromachining, have been developed. Miniaturized total analysis systems (pTAS) have been studied and some prototypes developed. In microfabricated systems, microfluidics , which represent the behavior of fluids in small sized channels, are considered and are very important in the design of micro elements used in pTAS. In this chapter microfluidics applied flow devices, micro flow control devices of active and passive microvalves, mechanical and non-mechanical micropumps and micro flow sensors fabricated by micromachining are reviewed. 

Paegel, B.M., Hutt, L.D., Simpson, P.C., Mathies, R.A., Turn geometry for minimizing band broadening in microfabricated capillary electrophoresis channels. Anal. Chem. 2000, 72(14), 3030-3037. 

Ermakov, S.V., Jacobson, S.C., Ramsey, J.M., Computer simulations of electrokinetic transport in microfabricated channel structures. Anal. Chem. 1998, 70(21), 4494M504. 

Brahmasandra, S.N., Ugaz, V.M., Burke, D.T., Mastrangelo, C.H., Bums, M.A., Electrophoresis in microfabricated devices using photopolymerized polyacrylamide gels and electrode-defined sample injection. Electrophoresis 2001, 22(2), 300-311. 

Mogensen, K.B., Petersen, N.J., Hubner, J., Kutter, J.P., Monolithic integration of optical waveguides for absorbance detection in microfabricated electrophoresis devices. Electrophoresis 2001, 22(18), 3930-3938. 

Cheng, J., Shoffner, M.A., Hvichia, G.E., Kricka, L.J., Wilding, P., Chip PCR. II. Investigation of different PCR amplification systems in microfabricated silicon-glass chips. Nucleic Acids Res. 1996, 24, 380-385. 

Tang, T., Ocvirk, G., Harrison, D.J., Iso-thermal DNA reactions and assays in microfabricated capillary electrophoresis systems. Transducers, 1997, Jun 16-19, 523-526. 

Sorouraddin, M.H., Hibara, A., Proskurnin, M.A., Kitamori, T., Integrated FLA for the determination of ascorbic acid and dehydroscorbic acid in microfabricated glass-channel by thermal-lens microscopy. Anal. Sci. 2000, 16, 1033. 

Also, EOF velocity in plastic microchannels had been imaged using video imaging of caged fluorescent dye [92], Dispersion of the uncaged dye for microchannels composed of poly-(dimethylsiloxane) (PDMS) was similar to that found in fused silica capillaries. The calculated EOF mobilities in different mobile-phase systems for various channels (acrylic, PDMS, acrylic/PDMS hybrid) were similar. This work shows that EOF profile is similar in microfabricated devices and in capillary columns. 

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