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New
frontiers of engineering-fifth wave of technology The
frontiers of engineering are advancing on many unexplored territories.
In the 19th and 20th centuries, we were driven by the desire to
go big. We have seen giant skyscrapers, suspension bridges, aircraft,
chemical processing plants, etc. Such developments significantly
improved our standards of living. The aviation industry peaked in the 1970s and thereafter reached a steady state. The same is true of the information technology industry, which peaked during the last two decades of the 20th century and has seen a gradual downturn over the past five years. New
waves of technology The fifth wave of technology, which we are riding today, is about Nobel Prize winner in Physics, the late Professor Richard Feynman’s ideas and vision. Many things he mentioned have become possible in recent years or will become possible over the next few decades. MEMS technology came to the forefront of engineering in the early 1990s although some applications existed before that. It is a technology similar to that used for making computer chips. Today, a computer chip the size of your thumb can perform 10 billion operations per second. Advances in semi-conductor technology for more than a decade have enabled building very small-scale mechanical devices and objects such as beams, plates, gears, motors, actuators, etc. Could we build a micro-robot that navigates through blood vessels using bio-sensors to reach the site of a cancer for controlled delivery of a drug? This would be a much more effective way to treat cancer patients than current approaches such as radiation therapy. Research is underway to use MEMS technology to restore vision to people suffering from certain types of blindness. According to an article published in the Mechanical Engineering magazine of ASME, a group of engineers from several leading laboratories in the US is working together to design and build a microelectromechanical device that can be implanted on the surface of the retina. In this artificial retina, a microelectrode array will perform the function of normal photoreceptor cells, to restore vision for people whose photoreceptors cells have been damaged. The goal is to build an array of 1,000 electrodes, with each electrode having a diameter of 50 ìm. The 1000-electrode array, according to the researchers, will deliver enough optical resolution for patients to read and recognize fine shapes. Another interesting application of MEMS technology under development is an implantable device for monitoring blood glucose, oxygen, acidity or other chemicals. My colleague, Professor Mu Chiao, who holds a Canada Research Chair in MEMS and Nanotechnology in the Department of Mechanical Engineering, does this work. The proposed device is a square silicon chip, half a millimeter thick and two millimeters wide. It will have a self-contained power source and work by allowing chemicals in the blood to flow through it. A sensor measures chemical concentrations then sends this information to a tiny processor, which transmit the information to a receiver. A major challenge in implantable biomedical device technology is the power source. Lithium batteries have long been used to power implantable devices such as pacemakers and spinal-cord stimulators. According to Professor Chiao, MEMS-based implantable biosensors can become viable if a power source can be built using MEMS technology. To meet this need, Dr. Chiao teamed up with other researchers to build a micro-battery that runs on glucose from body fluids. He has applied for a US patent for this new battery. While MEMS researchers are searching for revolutionary new applications and MEMS technology rapidly advances towards mass production of micro devices for various applications, a new area of research that takes us deeper into Feynman’s ‘infinitesimal world’ has emerged. This is Nanotechnology. Feynman speculated about Nanotechnology nearly 50 years ago. Advances in Nanotechnology are expected to yield significant benefits in areas as diverse as advanced materials, water treatment, information and communication technology, computer technology and medicine. Advanced materials have played a critical role in technological advances over the past four to five decades. Today we have composite materials that are not only much lighter than steel but several times stronger. Nanotechnology would allow us to build, starting at the atomic and molecular levels, new materials that have novel properties, functions and applications. Carbon NanoTubes (CNT) are an important class of nanomaterials in the development of this new generation of materials. There are two types of carbon nanotubes: single-walled or multi-walled. The diameter of a carbon nanotube is only a few nanometers and the length varies between a few micrometers to centimeters. Carbon nanotubes are not only extremely stiff and as strong as diamonds, they can also conduct electricity extremely well. Current R&D efforts are focusing on the application of CNTs in reinforced composites, sensors and nanoelectronic devices. In addition, some nanomaterials, such as nanocrystalline ceramics, have properties that may result in superior quality medical implants. Nanotechnology could be used one day to build a new generation of smart materials that posses the ability to sense, actuate and perform self-repair. There will be many exciting applications of Nanotechnology in medicine. One of the most exciting areas is in drug and gene delivery. The challenge is to build a nanoparticle with an on-board sensor that can destroy specific diseased cells by using controlled delivery of drug molecules or introduce new, stronger DNA molecules to repair damaged cells. This dream may not be realized for another 20-30 years but the groundwork is being laid today in leading laboratories. Let me take a minute to explain why I am interested in MEMS and Nanotechnology. My area of specialization is Solid Mechanics, which deals with the mechanical behaviour of materials, and forces and deformations in structures and devices under various types of loading. Now think about the structures and devices encountered in MEMS and Nanotechnology. Consider a practical example of a MEMS device where a crack could grow at a rate of less than one micron per day. How do we model and understand fracture at that scale to ensure reliability of MEMS devices? Another good example is in biomedical applications where nano-scale holes are created in a plate device to allow transfer of cells and fluids. Civil and Mechanical engineers have studied stress concentration around notches and holes in plates for a long time. Could we use such solutions at the nano-scale? At the nano-scale, surface energy and quantum effects play a dominant role. What happens when a fluid flows through a micro or nano-scale channel? Research shows that modeling of devices at the nano-scale cannot be done by classical continuum mechanics or fluid mechanics. New theories accounting for surface energy and quantum effects have to be developed. I am therefore interested in developing new theories and computational techniques to study the mechanics of nano-scale and micro-scale objects. Hydrogen
Technology Motor vehicles and electric power generators are the prime sources of carbon monoxide and carbon dioxide in the atmosphere, which contribute to global warming and climate change. Motor vehicles also emit nitrogen oxides, sulphur and carbon particulates (or soot) which cause serious health problems in humans. Around the world today, billions of dollars are spent on research and development programs in the area of clean energy technology. Alternative fuels such as natural gas, ethanol, methanol, etc. have been studied for many decades. It is well known that electric vehicles have many advantages over conventional vehicles run by internal combustion engines. The main advantages are efficiency, no pollution and low mechanical wear and tear due to fewer moving parts. I would like to talk about a new frontier of engineering that would make cars powered by a device analogous to a conventional battery viable and efficient. The device is powered by hydrogen, and research is underway in leading industrial and government laboratories around the world. The Clean Energy Research Centre at the University of British Columbia (UBC) and the Institute for Fuel Cell Innovation of the National Research Council of Canada located at UBC are leading Canadian centres for hydrogen-based clean energy technology. Hydrogen is the most abundant chemical element in the universe. Think of the abundant amount of water and plant life on earth as sources of hydrogen. Hydrogen can be considered the ideal fuel because of its inexhaustibility and compatibility with nature. How do we use hydrogen to run a car or produce electricity for an industrial plant? The answer is a device called a fuel cell. A Swedish scientist first introduced the concept of a fuel cell in 1838. A fuel cell is similar to a conventional battery. It is an electrochemical device, which uses hydrogen and oxygen as the reactants. Hydrogen and oxygen are fed to a fuel cell from an external supply. The reactants are therefore continuously supplied, unlike in the case of a traditional battery. A continuous supply of reactants allows for continuous long-term operation of fuel cells. The only by-product of a hydrogen fuel cell is water vapor. I am sure you have an obvious question for me. Why are we still running cars and power generators on petrol and diesel instead of using fuel cells? Although hydrogen-based fuel cell technology looks very attractive from a pollution point of view, there are significant technological challenges in getting our cars and other equipment run by fuel cells. What
are these challenges? The first hydrogen refueling station was opened in Iceland in 2003. There are also issues in the design and manufacturing of fuel cells with respect to materials, water management and temperature. Major auto and electric power industries are investing substantial resources (multi-millions of dollars) to address these key technological barriers. Research is also underway to replace batteries used in many industrial equipment and consumer electronic products by fuel cell powered batteries. There are already demonstration cars and buses in operation. A hydrogen highway is planned from Vancouver to Whistler in Canada. It is expected that most major technological challenges will be addressed over the next two decades and that hydrogen-based clean energy technology will be implemented by automobile and other industries. Applications with power demands below 1 kW constitute a potential market niche for fuel cells. Examples of these applications include communication systems, power tools, portable electronics, sensors for remote locations, and a large number of recreational appliances. Small-scale power plants (1 to 50 kW) for residential and commercial applications (e.g., restaurants, hospitals, and hotels) are another area with significant potential. Large-scale power generation (100 kW – 2MW) from fuel cells is also under consideration. Impact
on Engineering Education Engineering programs became too compartmentalized and students today have difficulty in seeing interconnections between core subjects. Such approaches to engineering education discourage interdisciplinarity and produces engineers with poor system integration skills. Another issue to note is the emergence of Biology as a core discipline of engineering in the 21st century. This is a challenge because Biology has never been a part of the engineering core. However, think about emerging areas such as Nanotechnology, tissue engineering, bio-electronics and the vast opportunities in the health and communication technology sectors. In these areas, great inventions will be made based on biological systems. We therefore need to think seriously about including core elements of Biology in relevant engineering curricula. In my opinion, there is strong merit in having a common curriculum, based on core engineering sciences, design, mathematics and basic sciences for the first two years of undergraduate engineering programs. Sufficient specialization can be achieved in the remaining two years, and postgraduate studies should be the avenue for further specialization. Some of the world-renowned institutions such as Harvard University have a strong component of core engineering sciences and integration of Biology in the undergraduate engineering programs. Two weeks ago, I had lunch with a former CEO of a Canadian advanced technology company. According to him we need only two types of engineers to drive the knowledge-based economy of the 21st century. One is an engineer with strong system integration skills to create the inventions, and the other is an engineer with strong product management skills to generate value out of these inventions. I think that is an important message for engineering educators around the world. |
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