Microfabrication future

It is to be expected that in the near future more of such concepts will find application, simply for cost reasons. Laboratory-scale investigations with precisely microfabricated reactors in advance of the use of such devices can give valuable information, providing a best-case scenario. From then, one can look for alternative micro-flow solutions of lower cost, higher reliability, higher flexibility and so... 

Andersson H, van den Berg A (2004) Microfabrication and microfluidics for tissue engineering state of the art and future opportunities. Lab Chip 4 98-103... 

Micro milling was applied frequently in many early applications of micro structuring. Microfabrication of the parallel channels was performed by micro milling of metal tapes at the Karlsruhe Research Center (Forschungszentrum Karlsruhe) [138], In the case of aluminum alloys, ground-in monocrystalline diamonds were used [139], In the case of iron alloys, ceramic micro tools have to be used owing to the incompatibility of diamonds with that material [44], It is certainly a useful tool for experimental work and rapid prototyping, but not a choice with respect to future mass production. 

Microfabrication is growing in importance in a wide range of areas outside of microelectronics, including MEMS, microreactors, micro analytical systems and optical devices. Photolithography will continue as the dominant technology in the area of microelectronics for the foreseeable future. Photolithography has, however, a number of limitations for certain types of applications, as discussed in Sect. 3.1. 

Future work will focus on real three-dimensional electrodes that may slowly penetrate the superficial layer of the retina. We hope to improve the spatial selectivity of a stimulator structure and to lower the energy consumption during stimulation, when the microelectrode is in close proximity to the somata of the ganglion cells. A possible design of this structure is shown in Fig. 27. It demonstrates the design potentials that microfabrication of polymer based microstructure offer. 

Layer thickness The typical film thickness used by the microelectronics community lies in the range between about 0.1 and 2.0pm, which is relatively small in comparison to microfabrication, where layers of up to 50 pm or more have to be deposited and structured. In future, film thickness in microelectronics will continue to decrease with increasing number of stacked layers, whereas in microfabrication the range of thickness will increase in both large and small vertical dimensions. 

On the other hand, the future of CEC may lie with the exciting developments in microfabrication [14], where capillaries are open channels 1.5 /tm wide and 4.5 cm long and can achieve efficiencies of 800,000 plates per meter. 

There are now considerable efforts being made to develop and manufacture miniaturized analytical devices (see Chapters 4 and 10) that wiU enable faster analytical times to he achieved, with smaUer sample requirements. There are now several examples in the field of microfabricated devices that have been shown to meet these aspirations. In the future, continued technological advances will result in even smaUer devices that can be taUored for a large number of analytes and that are very simple to operate. 

Use of capillary electrophoresis has been a great success in pharmaceutical analysis. Its further extension to microfabricated electrophoresis devices is anticipated to gain momentum in the not too distant future. 

Miniaturization has already enabled significant inroads to be made toward the development of parallel analytical systems. For example, microfabrication techniques have been used to produce ESI emitters in an array format [89,90]. Miniaturized arrays of ion-trap mass spectrometers are being tested and developed with some success, and promise at least mass selective detection in a miniature parallel device in the near future [91]. 

As outlined, microfabrication has revolutionized medicine and pharmaceutical technology. BioMEMS range from molecular motors utilizing intracellular ATP as an energy source [87, 88] to point-of-care diagnostics. These systems have been described as extremely sensitive biosensors and multi-well delivery systems. In the future we can expect another wave of miniaturization, new self-cahbrating systems [89], and improved analytical properties... 

Polymeric microfluidic systems coupled to a microfabricated planar polymer tip can be used as a stable ion source for ESI-MS. A parylene tip at the end of the microchannel delivers fluid which easily produces a stable Taylor cone at the tip via an applied voltage. The described device appears to facilitate the formation of a stable spray current for the electrospray process and hence offers an attractive alternative to previously reported electrospray emitters. When this interface was employed for the quantification of methylphenidate in urine extracts via direct infusion MS analysis, this system demonstrated stable electrospray performance, good reproducibility, a wide linear dynamic range, a relatively low limit of quantification, good precision and accuracy, and negligible system carryover. We believe polymeric devices such as described in this report merit further investigation for chip-based sample analysis employing electrospray MS in the future. 

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