Optomechatronics--An Overview to Modern Technology

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Engineering is one of the key crafts and professions that has for millennia been part of the driving intellectual energy of economic development and social change as far back as the earliest civilizations[1]. As the twenty-first century nears, Engineering's role is more important than ever. With humanity's growing numbers and demands placing ever-increasing pressure on the resources of a shrinking world, creative and thoughtful use of engineering and technology will remain essential for solving the problems of energy, food, transportation, housing, health care, communication, manufacturing, education, and environmental protection and for fulfilling all the other requirements of modern life.
An explosion of technology is occurring. It is not an explosion that affects the outward look of the landscape, as occurred in the period from 1850 to 1950 with the emergence of factories, large bridges and dams, automobiles and airplanes, highway systems, electronic power systems, telephones, and televisions. Instead, it is a revolution in the way things are designed, made, and controlled--in what they are made of and how they work. This technological revolution is more subtle than past ones but just as pervasive and important in its impact and on human life. Many of the technologies of today and tomorrow are internal rather than external in their function and impact; often they operate on a microscopic and molecular scale-- or even invisibly, in the electromagnetic spectrum.
To adapt to the changing context of engineering, future engineers will have greater intellectual breadth, better communication skills, a penchant to collaboration, and a habit of lifelong learning[2]. Among these characteristics, It is essential that the knowledge they obtain will be broad enough to be comfortable with systems-oriented work and be able to move with relative ease between different specialized areas of engineering research.
Given the rapidity of the technological change, some interdisciplinary and multidisciplinary engineering areas are formed by integrating traditional engineering disciplines with new techniques. In this work, optomechatronics is proposed as a general engineering area for engineers to meet the challenge of intellectual broadness in technology.

II Optomechatronic philosophy

2.1 Definition
Optomechatronics is the integration of optical, mechanical and other traditional engineering areas with microelectronics in order to unify machine and information technology. The knowledge structure of optomechatronics is shown in Fig. 1.

Fig. 1  The knowledge structure of optomechatronics

Information technology is computer technology appropriate to the encoding, storage, communication, manipulation, and use of information in digital form. Information engineering is the synthesis of new and old information techniques, producing the least cost method of distribution of services, production of labor, ecological revitalization to our world and more[3]. Examples include digital library, electronic education, electronic commerce, computer-based patient records and computer-based collaborative engineering. Information engineering is the fastest growing sector of modern industry. Microelectronics has experienced an exponential growth in the last five decades and is heading from the Mega to the Giga and Tera age in terms of speed and pixel density as feature size decreases from 0.5 to 0.05 micron[4]. Microelectronics and packaging technology is a keystone in modern industry.
In the past, the integration of electronics with mechanical components has often been more by coincidence or desperation than by design. Microprocessor controllers have often been merely added on to existing electro-mechanical systems. If the best properties of mechanical, electro-mechanical and microelectronic components are considered at the concept stage, a fully integrated design is possible offering dramatic improvement in performance. This is mechatronics.
With the increasing application of optoelectronics and laser technology to a wide range of consumer products and capital plant, optical engineering may often also need to be considered from the onset of the design exercise. Optical and laser-based technology provides a means of sensing engineering parameters such as distance, velocity, and deformation and can be integrated into equipment and used as a valuable tool at the development stage[5].
There are other interdisciplines which study the fusion of traditional techniques with microelectronics such as thermoelectronics, acoustoelectronics, and so on.
2.2 Characteristics
2.2.1 Interfusion
The interfusion of the traditional engineering areas with microelectronics forms the interdisciplines such as mechatronics, optoelectronics, thermoelectronics etc. The purposes of these interdisciplines are to study the sensors which transfer non-electronic signals to an electronic signal and the devices that can be controlled by electronic signals to generate non-electronic variables or energy. The digital computer is the bridge between microelectronics and information technology. Computers and computer networks provide the information infrastructure which can be universally accessible, day and night, at home and at school and at work.
2.2.2 Interdependence
The traditional technologies provided important infrastructure for the microelectronics industry and physical support for electronic products while microelectronics and information technologies are essential for innovation of conventional machines. Information technology can provide important software tools (CAD/CAM/CAE) to design parts and systems for microelectronic and traditional engineering areas.
2.2.3 Entirety
Although the mechanical and optical engineering incorporates with microelectronics earlier and is the essential part of optomechatronics, other fusions are also in progress including thermoelectronics, piezoelectronics, acoustoelectronics, etc. Optomechatronic philosophy is unitiation of all the engineering areas.
2.3 Conclusion
The insular attitude to electronic, optical, and mechanical engineering is initiated at an early stage in the engineer’s career by the need to select a single discipline degree course and is perpetuated by the departmental structure of most industrial companies. Optomechatronic philosophy not only offers a remedy to this problem but will also reshape the education and research in engineering in general. Optomechatronics, energy electronics and new material and properties provide the full option in the technology aspect of product design to achieve optimal products. This integration may sound like a Utopian ideal , but if achieved it can have many benefits both to the final product and the efficiency of the company.

III Optomechatronic product

3.1 Introduction
Currently, people in the engineering society are easily confused by all kinds of new concepts such as intelligent machines, smart products, mechatronic products, MEMS(microelectro-mechanical systems), MCMs(multi-chip modules), human-machine systems, and KBS(knowledge-based systems), etc. We prefer the term optomechatronic product to all the names although they are proper on the specific perspectives. A microprocessor is the centerpiece of an optomechatronic product. Computers and robots are the masterpiece of optomechatronic products. A robot is a computer with arms and/or legs. Almost all the modern instruments and equipments are specialized computers.
3.2 Definition
An optomechatronic product is a machine with knowledge and intelligence, which can process information and take action in response to human beings, other machines and the environment.The generic model of optomehatronic products is shown in Fig. 2.

Fig. 2  The generic model of optomehatronic products

3.3 Properties
3.3.1 Openness
An optomechatronic product is an open system which is able to interact with human beings, other machines and the environment through corresponding channels. Each channel can be one-way or two-way. Channels are also used to connect cells inside the optomechatronic product.
3.3.2 Hierarchy
There are three levels in the hierarchy of an optomechatronic product: physical, logical, and operational. Non-electronic signals can be converted to electronic signals, electronic signals can control physical variables and energy, analog electronic signals can be transferred to digital data, raw digital data can be formatted into multimedia like text, graphical, audio, video, etc.
3.3.3 Recursion
There may be one or many optomechatronic products inside an optomechatronic product. One product can be a subsystem of another one.
3.4 Conclusion
An optomechatronic product incorporates a machine with information into a system. This will allow new sophisticated equipment to be developed for future medical, biological and cosmical industries.

IV Future Trends

4.1 Introduction
The explosion of technology is occurring and new techniques and concepts are appearing very fast. People feel uncertain about technology in the future. We envision three fundamental trends in optomechatronics and optomechatronic product.
4.2 Trends
4.2.1 Smaller
We are familiar with micro?, like microengineering, microtechnology, microsoftware, microelectronics, micromechanical, micromechatronics, microoptics, microfluid, etc. and microsystem, micromachine, MEMS (microelectro-mechanical system), and so on.
Advances in information devices are made possible by decreasing the bit cell size with a sufficient signal to noise ratio. To accomplish this, it is very important to increase the preciseness in machining, positioning and motion control of recording media and transducers. At the same time, it is also necessary to reduce mechanical disturbances such as vibration, friction, wear and temperature increases. The scientific and engineering techniques used to achieve this goal are micromechanics, microtribology, and micromechatronics.
The length scale involved in these devices is shifting from micro/sub-micrometer to nano/sub-nanometer. Micromachine technology, which first originated from LSI manufacturing technology, is now contributing to the innovation of key components used in information equipment. Miniaturization, micro/nano-technology and preciseness are key concepts in the advancement of information equipment.
For precision equipment such as machine tools, LSI manufacturing equipment, various types of measuring instruments and so on, it is essential to increase the resolution of physical signals with a wide dynamic range. The science and engineering used for this purpose will be also termed micromechatronics. This includes micromechanisms, mechanics, tribology, machining, measurement and control. In addition, various kinds of scanning microscopes that reveal the nanometer surface structures have recently been developed, and the precision equipment used in this area is now undergoing rapid innovation[6].
4.2.2 Swifter
The conventional computers follow a serial model called Von Neumann machine, in which one processor performs one instruction at a time. Although processing speed is being improved rapidly with the advance of VLSI technology, they have not provided enough computational power to satisfy the demand for solving the complex problems in machine vision, motion planning, virtual reality, communication, and so on.
Parallel processing is another way to improve computer performance. The parallel computer is the type of high performance computer that harnesses many processors together to solve a problem. A variety of parallel architectures and algorithms have been investigated. Physically, parallel can be implemented in chip(circuit), package or machine level.
The information highway is emerging as the axis of inter-machine communications. Current PCs will become a network of PCs in the future. The highway is a webwork of powerful (high-capacity) computer-communications networks capable of handling everything from video to voice , text to computer data and graphics interchangeably, interactively and at a lightening speed[7].
One of the final goals of optomechatronics is to build an agency which can interact with the real world(human beings, other machines, and the environment) in real time. The response time should be limited only by physical properties of the machine.
4.2.3 Smarter
AI(artificial intelligence) is an experimental science whose goal is to understand the nature of intelligent thought and action. This goal is shared with a number of longer established subjects such as philosophy, psychology, and neuroscience. The essential difference is that AI scientists are committed to computational modeling as a methodology for explicating the interpretative processes which underlie intelligent behavior, that relate sensing of the environment to action in it. Early workers in the field saw the digital computer as the best device available to support the many cycles of hypothesizing, modeling, simulating, and testing involved in research into these interpretative processes, and set about the task of developing a programming technology that would enable the use of digital computers as an experimental tool. A considerable amount of time and energy over the last 35 years or so has been given over to the design and development of new programming languages, tools and techniques. While the symbolic programming approach has dominated, other approaches such as non-symbolic neural nets and genetic algorithms have also featured strongly, reflecting the fact that computing is merely a means to an end, an experimental tool, albeit a vital one.The popular view of intelligence is that it is associated with high level problem solving, i.e. people who can play chess, solve mathematical problems, make complex financial decisions and so on[8].
The term Knowledge-Based System(KBS) involves the integration of AI know-how methods and techniques with methods and techniques from other disciplines such as Computer Science and Engineering to construct systems that replicate expert level decision making or human problem solving to make it generally available to technical and professional staffs in organizations[9]. AI/KBS is migrating into industry and commerce and a wide variety of university departments.
4.3 Conclusion
Optomechatronic products will become smaller and faster, and intelligence and human capabilities will be incorporated into these machines. Will AI created on the materials overgrow human intelligence? The answer is no. AI, like expert systems and neural networks, do not replace human thought anymore than the motor car replaces human feet. No matter how it will be improved, a modern machine essentially has no difference with the earliest man-made artifact like stone. It is a human-made tool but a complicated one.

V Conclusion

Under the theory that all things are one, optomechatronics is presented as a united area of engineering forged from different disciplines, traditional and new, science and technology.
Technology has changed human society from the pre-industrial age, through industrial and information ages, to post-information age. This century will go down in history as the century of technology. In these almost one hundred years we developed the ability to move people and things between any two points on the globe in hours and to keep those points in instantaneous communication. We sow, reap , cook, communicate, manufacture, travel, clothe, entertain, educate, research, manage, cure, and kill by highly technological means.
Engineering will be challenged as never before to shape the nature and quality of life in the twenty-first century. Future engineers will have the optomechatronic vision in technology and be able to work together efficiently in teams to identify and solve complex problems in industry, academe, government, and society.

[1] Terry S. Reynolds, editor, "The Engineer in America: a historical anthology from technology and culture", The University of Chicago Press, Chicago, 1991.
[2] Board on Engineering Education, Commission on Engineering and Technical Systems, Office of Scientific and Engineering Personnel, National Research Council, "Engineering Education: design an adaptive system", National Academy Press, Washington, D.C. 1995.
[3] Center for Information Research(CIT), Stanford University. http://logic.standford.edu/cit/cit.html.
[4] ONR European Office, Newletter#54 on Electronics by Nick Bottka, Report on NATO Advanced Research Workshop on Future Trends in Microelectronics, 7-Aug-95. http://www.ehis.navy.mil/nbnews54.htm.
[5] MSc Mechatronics and Optical Engineering, Mechatronics Group, Department of Mechanical Engineering, Loughborough University. http://info.lut.ac.uk/mechatronics/mechatronics.html.
[6] International Conference on Micromechatronics for Information and Precision Equipment(MIPE’97), July 22, 1997, International Forum, Tokyo, Japan. http://dycon.mech.titech.ac.jp/MIPE97/shushi_h.html.
[7] Heather Menzies, "Whose Brave New World: the information high and new economy", Between The Lines, Toronto, Canada, 1996.
[8] Department of Artificial Intelligence, University of Edinburgh.
http://www.dai.ac.uk/AI_at_Edinburgh_perspective.html.
[9] Fatemeh Zahedi, " Intelligent Systems for Business: Expert Systems with Neural Networks", Wadsworth Publishing Company, Belmont, California,1993.