Preface

Small, smaller, nano: “What happened?”. Posing this question insinuates that “micro” has not made its way into the popular scenarios of opinion makers. Micro has had tremendous success in the microelectronics industry, but all other fields lack attention. It is not my current intention to evaluate why micro lacks impact on society and nano is overrated, but to provide a book on Microfabrication for Industrial Applications. This is because of two reasons: (1) I have spent the last twenty years in this field of research and I am fascinated by the fact that not only can we fabricate a hole of 10 μm diameter, but also we can make it at a precision of 10 ± 0.05 μm under mass production conditions, and, (2) I am not only a scientist in this field but also an entrepreneur.

Having spent a decade of my professional career in Twente, the Netherlands, it is inevitable that I should present some examples of its successful spin-off activities, specifically, from the University of Twente’s MESA+ Institute for Nanotechnology.

Let me briefly take the opportunity here to give you some facts about the University of Twente. It was established at the very east of the Netherlands in 1960, with the purpose of upgrading the region’s economy through education and employment. Today, it is one of the largest organizations in the region, with 3300 employees and 9000 students studying high-tech sciences, (medical) engineering technologies (including ICT), business and public administration, communication, and psychology. The University’s slogan, “High-tech, human touch” is not just a phrase; it has become a center for cultural and economical redevelopment of an environment that was previously in decline.

I would also like to refer to some of the influences that helped me to produce the book in its present form. First of all, I have to thank the Dutch Science and Technology Foundation, STW, for funding my research activities, and the University of Twente and the Science Park of Twente for providing me with a working environment in which it was possible to dedicate my time and effort to the book. I was also able to learn that technology transfer is about people as much as technology.

The research group Mesoscale Chemical Systems is affiliated with the MESA+ Institute for Nanotechnology, headed by Prof. Dr. J.G.E. Gardeniers. It provides me with a superb facility for research on micro-nanofabrication. I am therefore very much indebted to Prof. Dr. J.G.E. (Han) Gardeniers. He has given me a scientific home in his research group.

This book was intended to be joint effort between Han and myself, about three years ago. Due to the many tasks resting on Han’s shoulders in his position as head of the group, he asked me to write it alone. When we suggested this solution to the publisher, Elsevier, I was overwhelmed with the trust that they all had in me, and I was determined to complete the project for the reasons stated above, and also because I read the second year undergraduate course Lab-on-a-Chip Technologies in a project-oriented approach. I felt that a book dedicated to microfabrication for industrial applications could bring together the endlessly scattered background information onto one line of thought, which would enable students to familiarize themselves with the design of future Lab-on-a-Chip products, as well as to get a general understanding of the needs for miniaturization in society. The present book, therefore, provides an introduction to the topics around the concept of the Lab-on-Chip and related fields of microfabrication technologies, for students and non-specialists.

Thanks to Matthew Deans, Senior Publisher, and Frank Hellwig, Editorial Project Manager at Elsevier; I realize that it is OK to restrict the content, instead of “wanting to write it all”. I eventually made sufficient progress on the book project when I was ready to see that it made sense to reuse some of my previously produced texts. I refer, here, mainly to my own previously unpublished PhD thesis on “Fabrication technologies for optical scanners based on micromachined cantilevers”, (Imperial College, London, 2003), which laid the foundations for Chapters 2 and 5, and three specific publications, which I (co)authored between 2007 and 2010, that gave an overview of nanolithographies for nanoarrays (discussed in Chapter 4) and the utility of microchip capillary electrophoresis (discussed in Chapter 7). I present these parts here in one coherent line of thought. I noticed that the text that was originally intended as a scientific contribution fulfils its purpose as a stand-alone document in the expert community, but not necessarily as a source for students or non-experts who wish to learn about micro-nanofabrication. Therefore, I felt that it was permissible to incorporate these previous texts as central core information in this book.

This process also made me realize that if students see a gap between scientific information, and that supplied for educational purposes, it may also be a hint for bridging what society experiences as the technology gap between science and its application. The objectives of this book are first to allow the reader to become familiar with the field of microfabrication, and second to give the reader a guideline for assessing the potential of any new technology that is based on microfabrication, thus reducing the investment risk by means of a simple academic tool: desk research.

This book is set out in nine chapters. Chapter 1 gives a brief introduction to the value-creation process of a commercial technology implementation chain by securing a patent. Chapters 2–4 illustrate the technical background knowledge of process engineering for micro-nanofabrication purposes. Chapter 5 concentrates on a more classical microtechnology field: the microtransducer, while Chapters 6 and 7 present an introduction to (bio)chemical sensors and microcomponents, and the technologies used in the life-sciences industry. Chapter 8 illustrates the concept of academic desk research, which is applied to evaluate microneedle array technology for its application in diabetes management. This specific application is far beyond the original scientific project goals. However, it is via this type of project after care analysis that I am able to begin screening the depth of societal and economical impact of the novel technologies developed in the lab. I propose that the latter allows scientists to get in touch with key-technology managers in relevant industries. Eventually, we all have to realize that it is industry which must balance the budgets of these identified values with the actual available resources for development throughout a product’s life-cycle.

The book could not have been written without the support of others. A considerable part of my scientific research consists of collaboration with other scientists and technologists. This work is incorporated to a large extent in Chapters 4, 7 and 8. Specifically in the work on nanofabrication for biomaterials, my thanks are due to Prof Dr. J.A. Jansen and his research staff at the Department of Biomaterials, Radboud University Medical Centre, Nijmegen, The Netherlands, and to my recent PhD student here at MESA+, Maciej Domanski, who combined most spectacularly in the course of his project the capabilities of laser interference lithography (LIL) into a new nanofabrication technology for medical-grade bulk titanium implants. The utility of LIL as a nanolithographical technique and its subsequent application is discussed in more detail in Chapter 4. The other extensive collaboration project I was involved with is the work on microneedle array technology discussed in Chapter 8, as an example of desk research, which is one important driver for innovation. With respect to this collaboration, I wish to thank Prof. Dr. R.J. Scheper and Dr. T.D. de Gruijl at Free University Medical Center, Amsterdam, The Netherlands, for their honest and motivating belief in this novel technology for advanced cancer vaccination therapies, by means of which they have also inspired spin-off applications of University of Twente’s patent-pending ceramic, nanoporous microneedle array technology for other SMART¹ products based on this platform technology. I truly hope to be able to secure the required funds and continue this collaborative study to validate the benefits of these types of nanoporous microdevices. Within this context of science enabling innovation I owe thanks also to the professionals with whom I am involved via the organization and teaching of the Entrepreneur Workshop for Physicists and Engineers, established by the Institute of Physics, UK, London, and with whom I have the most extraordinarily exciting exchange of ideas on the topic of entrepreneurship.

My thanks also include all my colleagues, technicians and fellow scientists, who consistently work (and have worked) with me towards the understanding and implementation of micro-nanofabrication. Furthermore, I would like to acknowledge the dedicated support of Jacqueline Emmerich-Nijenhuis, our group’s secretarial assistant, and Stefan Schlautmann, our group’s technical assistant, who always lend a helping hand.

Of course, there are also others who have made my life comfortable up until now, and I should not forget to express my gratitude to them. First of all my thanks go to my family, my two brothers and their families and of course my parents, who are all based in my home town, Vienenburg, Germany. They do not see or hear much of me since I left to find myself by building an academic career, although they are always in my heart, and without their love I could not live as happily as I do. Of course, there is more than science. I am particularly lucky that I have found in Michel a partner with whom I can share my scientific passion and my life, and without whose inspirational support and the tips and tricks he revealed to me from his own book project, I would not have been able to accomplish the book.

Finally, microfabrication is the essential core of microsystems technology (MST) that focuses on the miniaturization of engineering systems to accommodate the design specifications of small space, light weight and enhanced portability. At the onset of all miniaturization we mainly refer to the development of the integrated transistor, the workhorse device by means of which all the major new markets were created. The importance of MST lies, for a large part, in the economical and technical development of innovative systems in general, and particularly in the extended functionality which is made possible by this approach. An example of such miniaturized systems is the wide-scale utility of distributed transducer networks. The research field of microfabrication technology was established in industry approximately 50 years ago, and thus it is a relatively young business discipline with a high potential.

Leaving the question from above: small, smaller, nano: “What happened?” for you to answer, by starting your own journey around the world of micro-nanofabrication, I hope that this book will spark many new ideas for the implementation of microfabrication in industrial applications.

Last but not least: thank you. Your comments and suggestions for micro-nanofabrication implementations and its related topics are highly welcome.

Regina Luttger

March 2011, Enschede, The Netherlands

E-mail: [email protected]