Process microdevice technology

In the context of this paper, only the microdevices and the micropro-cess engineering for uses in tine chemistry and pharmacy are considered. The view will be process-based and deduced from a rough economic calculation of how mature the technology is and what needs to be done to promote it further. 

The latest advancement in femtosecond (fs)-based micromachining technology has opened a new window of opportunity for fabrication of microdevices. Direct exposure of most solid materials (including fused silica glass) to high power fs laser pulses may lead to the ablation of a thin layer of materials at the laser focal point13. Due to the multiphoton nature of the laser-material interaction, the ablation process can be conducted on the material surface as well as within its... 

The body of scientific knowledge behind food fabrication started to accumulate less than 50 years ago. It has been in the last 20 years that the study of foods as materials has become a field in its own. It has been fostered by advances in related areas, most notably polymer science, mesoscopic physics, microscopy, and other advanced physical techniques. Progress in separations science has led to economically feasible processes that make available refined and functional food ingredients that replace or complement traditional raw materials. New technologies, most notably the use of membranes and microdevices, promise to bring the scale of fabrication closer to that of micro structural elements in dispersed phases (droplets, bubbles). 

Part 11 elaborates on some of the topics presented and discussed in recent CPAC Summer Institute sessions at the University of Washington. The impact of microinstrumentation on high throughput experimentation and process intensification will be highlighted in these chapters as a valuable and emerging field of technology. The initial chapters describe fimdamentals and hardware developments and some techniques to monitor and characterize them. These are followed by a series of chapters that emphasize the applications and impact of the microdevices. 

Many technologies have been developed to monitor or measure fluid flow in microdevices. The underlying mechanisms of these devices are based mainly on thermal or mechanical principles examples of the variables to be measured are temperature, differential pressure, and drag force, which translate to thermal changes, deflection of cantilever beams, and shear strain, respectively. Most of these microflow sensors are manufactured by microelectromechanical systems (MEMS) processes without moving parts, and the flow rate measurements are mainly translated from velocity detection. For example, because flows in microchannels are in most... 

Plasma treatment of microfluidic surfaces can be used to improve microdevice functionality, to build devices through bonding processes, and to activate and sterilize surfaces. Future directions for this technology include improved modeling of techniques with respect to parameter and surface plasma interaction. The development of refined experimental methods, theoretical models, and experimental studies is required to have more control over plasma treatment within microchannels. 

We will not consider here the large domain of silicon-based microdevices (including silicon nitrides and carbides), which would hardly be considered for fuel processing at the industrial level due to the cost of the substrate material. A general literature review and detailed information on silicon technology-based microreactor... 

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