9.1 Environmental Aspects

All manufacturing industries must consider the possible negative effects of the technology they use, both in the product development phase and in the product itself. These concerns start from the refining of the raw materials, and continue to the creation of semi-finished products with specific material properties, as well as other related processes that have a possible impact on the environment throughout the product’s life-cycle. It is difficult to estimate the environmental impact of a micro-nanofabricated product’s full life-cycle and we will not try to generalize or condense this topic into one single section of a book chapter.

Nevertheless, I would like to address this topic, at least briefly, because of the urgent need to incorporate such considerations into micro-nanofabrication product design. Many dedicated funding schemes worldwide, and this book are intended to further stimulate the implementation of micro-nanofabrication into industrial application, and this should not be hampered simply by the lack of awareness.

Similarly to the previous chapters, this broad topic of environmental aspects of micro-nanofabrication is best addressed by an example from industry. I found this example by Williams et al. in the field of electricity-generating technologies who question whether photovoltaic (PV) systems, although producing little or no environmental pollution at the point of use, carry a significant environmental burden because of the types of materials and fabrication methods involved in their production [1]. Without going into their life-cycle analysis, we know that current state of the art is clearly capable of producing PV systems at a very large scale. Williams et al. conclude that there are significant opportunities for increasing the environmental performance of a PV system. This is where micro-nanofabrication may be able to offer technological solutions, e.g., by replacing currently-used batteries by novel means of energy storage systems.

A discussion of the possible routes for higher efficiency in energy storage systems is beyond the scope of this book. We can, of course, conduct desk research and bring all the different factors of currently existing scientific strategies to the point. Just to give an idea of novel concepts being developed in this field Birch examines the construction of an artificial leaf by means of micro-nanofabrication [2]. This example demonstrates that a micro- and nanofabrication concept may improve the overall efficiency of a given amount of available resources, and by itself does not form a direct threat to the environment, but the processes and materials in the product’s life-cycle still might.

It is therefore possible that micro- and nanotechnology could be used to optimize systems, by stimulating the selection of materials for a cradle-to-grave approach, to strongly reduce or even deminish completely an environmental negative impact of novel commercial products and processes [3–6].

9.2 Health Aspects of Nanoparticles

One of the most alarming examples of health risks we have experienced in recent years arising from technical solutions is the case of asbestos in the building industry. Asbestos was the number one material for fire protection and fire resistance. The material as used appears harmless, but exposes its danger upon aging, or when machined by drilling, etc. Under these circumstances fine-scale particles of a few micrometers in length are released. These whisker-type structures get stuck in the cellular tissue, specifically in the lung, initially causing a reduction in lung capacity, and also a possible carcinogenic reaction. Currently, these symptoms have no known cure.

This material has now been banned from production and use, and significant effort is made by industry and government to remove it from existing buildings. Although asbestos is now going to the grave to minimize future health risks, we have to realize that industries and governments have the responsibility of investigating possible health risks from the introduction of novel materials and products before they go to market.

Nanoparticles (μNP) are starting to be used in commercial products. These particulate systems are either designed as a stand-alone nanodevice in, e.g., drug delivery applications, or are used as the smallest building block within higher order architectures, e.g., in their incorporation into self-healing materials [7, 8]. These materials do not constitute a new risk to mankind. μNPs are all around us in nature, and many natural and artificially designed materials already contain them.

Our novel understanding of these μNP systems allows their controlled placement in artificially created systems at the molecular or atomic scale, e.g., from solutions or the gas phase. If the μNPs remain either in solution or within the solids created during a process, the materials are considered as safe. This concept has yet to be evaluated over the product’s full life-cycle. Of course, in cases that use powderized μNPs, special safety rules apply and are stringently followed, since we have learned so much about asbestos and its related diseases.

However, I believe that we are quite capable of organizing and installing appropriate rules for dealing with these substances. Like any other chemical, the health risks of μNPs can be identified and communicated through the appropriate channels within working environments.

Although I am not an expert on the design of such particulate systems, I do work on microreaction controlling technologies on chip that enable their fabrication, so I feel that it is important to mention these facts within the content of this book. I wish to point out that the risk is not that associated with working with μNPs. The real risk arises from combining artificially produced materials, by trial and error, and only considering the utility of the outcome. Scientists working in micro-nanofabrication have the opportunity to accumulate appropriate knowledge to counteractary any possible negative effects and any associated predictable risks when the materials are affiliated with traceable drivers. Scientific publication will not be enough; the results of research findings in μNPs should be disseminated via channels used by the general public. As a first source on μNP fabrication and their use I refer the reader to the contributions by Rottelo and co-workers [9] and Yang et al. [10].

In sum, I would like to suggest putting all the different types of effort concerning μNPs into one public–private research program, to investigate the design, ethical and technical validation of these novel technologies, as well as their clinical and economical impacts on society. Fragmented investigation approaches may simply spend tax-payers’ money on similar debates to those experienced in the development of genetically-modified food and organic feedstock. Such a process should not only provide a solution to a single technical problem (e.g., treating a specific disease) but should also provide long-term perspectives on the safety and sustainability of μNP technology.

9.3 Conclusions

This book is about microfabrication for industrial applications. It provides a first insight to the variety of technical processes and initial efforts regarding the implementation of these novel technologies in microdevices, e.g., sensors and actuators. Of course, the fabrication technologies at the nanoscale are part of this field, and become more and more important in applications. Utilizing micro- and nanofabrication technologies in real-world tangible products (raw materials, semi-finished or fully developed end-user products) is a task for the applied sciences and industries. These actors meet in the microsystems devices industry, which has evolved from the previously established and highly successful semiconductor industry.

Many recent innovations have been enabled by microfabrication. In this book we have studied a variety of cases at different levels of development. Resonant microsensors, for example, are already highly established in the market (accelerometers in our cars and mobile phones). The introduction of technologies including wet-state components is less advanced. Although microfluidics is being investigated by different scientific disciplines, its application in commercial products is still hampered by the complexity of systems design. On the other hand, once a viable outlet has been identified, e.g., working towards a point-of-care diagnostic device dedicated to the measurement of lithium in blood (see the case in Chapter 7), these technologies are clearly able to penetrate into their market place. Cross-disciplinary efforts produce rapid progress in the field of nanotechnologies. Nanoscience and nanotechnology anticipate also on the mimicking of many processes in biology that occur naturally at the nanoscale, and by the introduction of this novel field of work, societies can reach far beyond microtechnology as an occupation of engineering scientists alone.

However, there has not been a paradigm shift that would be comparable to the effect of the fabrication of the integrated electronic circuit according to Moore’s law¹ on the world’s overall living standards. These devices are reaching the physical limit of a line width that can act as a transistor, which signals the end of the microelectronic development era. This is why novel nanofabrication techniques must emerge to provide other means of fulfilling this logic function within the design of future systems. One concept is to carry out logical operations at the molecular level, switching, for example, the energy state of a π-bond in an organic chemical compound. The ability to create materials and systems from the bottom up is exciting and may indeed present society with a new paradigm shift.

These efforts will eventually provide us with solutions for specific needs. The nanosciences and nanotechnologies will feed the knowledge grid as much as other areas of knowledge-creating disciplines, and will create new disciplines, which eventually will lead to the continuous generation of marketable non-tangible and tangible products in a sustained environment. In the latter, microfabrication will remain a stable factor in the overlapping networks of industrial and academic actors that now, more than ever, explore the working mechanisms of smaller and smaller dimensions, in which MST offers more than Moore.

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