Microfabrication technology

Hierarchical structured surfaces have also been obtained by combining photolithography and dry etching methods, as typically used in MEMS fabrication [56, 57]. Single crystal silicon posts (1 [xm in diameter and height up to 50 [xm) supporting 

---

Microfabrication technology has made a considerable impact on the miniaturization of electrochemical sensors and systems. Such technology allows replacement of traditional bulky electrodes and beaker-type cells with mass-producible, easy-to-use sensor strips. These strips can be considered as disposable electrochemical cells onto which the sample droplet is placed. The development of microfabricated electrochemical systems has the potential to revolutionize the field of electroanaly-tical chemistry. 

All of the above trends make a planar platform configuration the ideal choice for the development of such sensors due to the compatibility of this geometry with a range of microfabrication technologies, the availability of low-cost materials for the production of such platforms and the robust nature of planar configurations when compared with alternatives based on optical fibres. 

R.P. Buck, V.V. Cosofret, E. Lindner, S. Ufer, M.B. Madaras, T.A. Johnson, R.B. Ash, and M.R. Neuman, Microfabrication technology of flexible membrane-based sensors for in-vivo applications. Electroanalysis 7, 846-851 (1995). 

Poly(methylmethacrylate), PMMA, Is a well-known degradable polymer in the radiation chemistry of macromolecule (1). Hatzkis reported that PMMA is an excellent resist material usable in the microfabrication technology for manufacturing the microelectronic devices where X-rays and electron beams are used as radiation sources (2). 

The development of microfabrication technologies for ceramic and metallic materials has significantly promoted, during the last decade, research in the field of microreactors, characterized by higher specific productivity, better control of operating conditions and a higher standard of intrinsic safety than large-scale reactors [33, 34]. 

Certainly, the selectivities, efficiencies, reproducibilities, and applications of nanoliquid chromatography (NLC) and nanocapillary electrophoresis (NCE) machines depend on the materials used for microchips. The microfabrication technologies originated from the microelectronics industry using silicon... 

Michel F, Ehrfeld W, Koch O, Gruber H-P. EDM for microfabrication—technology and applications. In Week M, ed. Proceedings of the International Seminar on Precision Engineering and Microtechnology, Aachen, July 2000. 

Smart WH, Subramanian K. The use of silicon microfabrication technology in painless blood glucose monitoring. Diabetes Technology Therapeutics 2000, 2, 549-559. 

Mathies RA (1996) Microfabrication Technology for Biomedical Applications. Cambridge Healthtech Institute, San Jose, California... 

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. 

---