Engineering Science Programme

What is Engineering Science?
Anjam Khursheed, ESP Director at NUS

There is currently, a great demand for all kinds of engineers. Beyond the traditional engineering disciplines, such as civil, electrical, mechanical, chemical, industrial, engineering is rapidly growing in new fields, such as medicine, biology and the environment. All are needed, and there are plenty of jobs to go round. Our Engineering Science graduates have been successful in finding jobs in a wide-variety of different ways. Some find jobs in traditional engineering disciplines, such as electrical power distribution. Others go to the newer high tech multi-disciplinary industries, companies in alternative energy technologies (eg, solar cells), in medical, communications and semiconductor industries. Quite a few ESP graduates have found jobs with government research centres such as DSO and A*STAR research institutes. A significant number of ESP graduates have started up their own companies, and many have gone on to do further studies, both in Singapore and prestigious universities such as Harvard university and MIT. Our graduates have found jobs in a wide variety of places.


When deciding on which course to study at NUS, a prospective student should mainly be guided by what they are interested in, strong passion and interest is the most secure foundation for a successful career. This leads us to ask, what topics are covered by Engineering Science? What kind of challenges does an Engineering Science degree prepare us to solve? The answer to this may not be obvious, since engineering is becoming increasingly multi-disciplinary in nature and a single engineering device or system may require knowledge of several disciplines. Let us take for example, the subject of Maglev.


Maglev Trains

When most people think of Magnetic Levitation, they think of Maglev Trains, trains that move without making contact to the ground, vehicles that use no moving parts to lift and propel them, a minimum friction system that relies on the force of invisible magnetic fields. Maglev is a complex interdisciplinary engineering electromechanical system which requires a very high level of engineering expertise.


The Maglev Train Magnetic Force Lift/Guide Principle
Maglev trains
(above picture taken from: https://en.wikipedia.org/wiki/Maglev)

Maglev obviously requires a great deal of training in electrical and mechanical engineering, so where does engineering science come in? The answer to this is best answered in terms of looking at the Maglev of the future, that is, to the research and development of Maglev. This naturally requires us to bring in fundamental scientific principles. Two examples of this in relation to magnetic levitation are given below: diamagnetic levitation and quantum levitation.


Diamagnetic Levitation

The following video link is a famous video on an internet website that shows a frog floating in mid-air, suspended and levitated in a stable way by magnetic fields.

How is this possible? Well the answer is, that just about everything is magnetic. At school we are often taught that only a few metals are magnetic (nickel, iron and cobalt), but that is a great simplification, in fact, almost everything is magnetic, not just the familiar ferromagnetism of permanent magnets or electromagnets.


Are you magnetic?

In physics, we learn that there is a dimensionless constant called magnetic susceptibility, χ, which tells us how magnetic a material, is, iron for instance, has a magnetic susceptibility that can easily exceed 100,000. However, things we usually think that are not magnetic, are actually magnetic, and have magnetic susceptibilities in the millionths (10-6) range. Even more curious, is that many materials, including human tissue, have negative magnetism, known as diamagnetism, that has negative magnetic susceptibility! Diamagnetism was first discovered by the English engineer Michael Faraday in the middle of the 19th century, over 150 years ago.

Water has a magnetic susceptibility of approximately 10-5, and is actually pushed away by a magnet! Did you know that it is relatively simple to do experiments to show that water is slightly pushed away by permanent magnets? There are a growing number of websites that are devoted to the new promising applications of diamagnetic levitation (things like frictionless bearings) using the more diamagnetic materials such as pyrolytic carbon, see for instance the following link:


This is the kind of subject that falls into the category of engineering science.

In the video of the frog being levitated, the experiment was actually carried out in a superconductor electromagnet solenoid where the field strength exceeds 10 Tesla (the surface of a permanent magnet usually has a field strength of around 1 Tesla). The floating frog is pushed up by the strong magnetic field of the superconducting solenoid into a region where it is stably floating.

Frog magnetic levitation principle
(Diagram levitation that appears in a paper by M. D. Simon and A. K. Geim entitled “Diamagnetic levitation: Flying frogs and floating magnets”, J. Applied Physics, Volume 87, Number 9, (2000), pp 6200-6204)
Mathematics is the common language of Scientists and Engineers

It is interesting to note that in 1842, a British mathematician by the name of Samuel Earnshaw published a theorem that subsequently became very important to the science of magnetic levitation, his theory can be used to state there is no way magnets can be arranged for them to be stable. Passive magnetic levitation is theoretically impossible. Understanding this fundamental principle is now an important engineering principle of magnetic levitation, and how that can be overcome by diamagnetic materials is a fascinating story. All this illustrates another important feature of engineering science, mathematics is an integral part it. Mathematics is the common language that scientists and engineers share, and it is a key component to engineering science.


Quantum Levitation-Locking

Another example of a more engineering science form of magnetic levitation is Quantum Levitation or Quantum Locking. See the video on the website link below of a how a thin disc stably floats above permanent magnets. It not only is stable, but locks into position holding its initial orientation! This is a new revolutionary form of magnetic levitation, how does it work?

To start with, an inert, chemically inactive disc is required, such as a crystal sapphire wafer. That wafer is then coated with a superconductor yttrium barium copper oxide. When superconductors become very cold (like liquid nitrogen cold) they conduct electricity with no loss of energy, which normal conducting materials like copper can't do. Superconductors, when cold enough, expel magnetic fields, but normally, when they do that, they would just repel the magnetic force and float in a wobbly fashion. However, because the superconductor is so thin in this case, tiny imperfections allow some magnetic forces through. These little magnetic channels are called flux tubes.

The flux-tube principle of Quantum Locking
Flux tube
(above picture taken from: http://io9.gizmodo.com/5850729)

The flux tubes cause the magnetic field to be "locked" in all three dimensions, which is why the disk remains in whatever position it starts in, levitating around the magnets. There are a growing number of engineering applications being proposed for this newly discovered technique, research and development of this kind of “technology” is something that aptly describes what we mean by engineering science.

Diamagnetic and quantum magnetic levitation are only two simple examples of subjects that fall naturally into the domain of engineering science, there are of course, many more. Engineering Science also encompasses many new applications of quantum physics, such as quantum computing, sensing, communicating and encryption. Quantum tunnelling is the basis of a microscope called the Scanning Tunnelling Microscope (STM) that can image atoms! Focused electron and ion beams can also be used to image atoms. Other Engineering Science techniques for imaging include Magnetic Resonance Imaging (MRI), commonly used to image the brain. Did you know that the MRI principle uses the fact that protons are ever so slightly magnetic? From self-powered multi-functional sensors required for smart sustainable cities, through to space satellites, there many cutting edge research areas where engineering science is required.