Living in a Material World

Before you read this article put the magazine down for a minute and take a look around you. Really take a good look.  What do you see? 

My guess would be that you are sat on a chair somewhere in a building, you can see out of the window (perhaps there is traffic on the road outside), you might be sat next to a computer or might be listening to your mp3 player while you are reading, you will be wearing clothes, maybe spectacles and you might have braces on your teeth.

The reason for me asking you to do this isn’t to show that I am psychic! The one thing that all the things around you have in common is that they are made of something!  Its pretty obvious really, but everything you see and use around you everyday has been engineered from materials. I can quite confidently tell you that there has been a materials scientist or materials engineer involved in designing, developing and manufacturing everything you can see (at least the man-made stuff anyway!).

Materials science or materials engineering is quite simply the study of materials. We need to understand everything about materials, from how the atoms inside them are arranged into crystals or molecules, to how materials can be formed to shape and how both of these things can change the properties of the material. By understanding these things we can design new materials from scratch to meet the needs of a new applications, improve materials that we already have to get better performance and most importantly, make sure the best material is chosen for the job. 

Throughout our history finding new materials and improving our understanding of them has gone hand in hand with advances in the technology we rely on. Materials have been so important that we have named key periods of time after the materials that we learnt how to use, we had the Stone Age, then the Bronze Age then the Iron Age and if we hadn’t come up with ways of processing iron and steel on a large scale when we did, the Industrial Revolution may have been very different. If you were to take a look around you now and try and choose one element, material or group of materials that has had the biggest influence on our technology over the past few decades it would probably be much more difficult as our understanding has improved so much so quickly. Here are a few materials that might just be contenders

The Silicon Age?

Over the past forty years our ability to build increasingly more powerful processors has improved dramatically. The reason we are now able to make home computers and games consoles that give almost life-like graphics and game play is that we understand how to process the element silicon. Silicon is a metalloid, that is it has some properties of metals and some of non-metals. Of particular interest is how silicon conducts electricity, it is a semiconductor. The microprocessor at the heart of your computer or games console is made from a small piece of silicon, perhaps the same size as a postage stamp. Electronic components such as diodes and transistors can be built within the surface layers of the silicon by very carefully doping it with other elements such as gallium and arsenic. By doing this on a minute scale it is possible to incorporate the equivalent of hundreds of millions of components on that postage stamp-sized piece of material!!  And don’t worry we have plenty of silicon to go round - it is the second most abundant element in the Earth’s crust and pretty much every rock that you see will contain it.

The Plastics Age?

Plastics have become in integral part of our everyday life and are materials that we all take for granted.  Just look in your fridge and you will see a variety of plastics used to package your food, such as polyethene (HDPE), PET (polyethylene teraphthalate) and polystyrene, you may well be wearing clothes made from plastics like nylon or polyester, you might be walking on polypropylene carpet and a range of different plastics are used to make the cases for the electronic equipment that we all rely on.  The majority of the plastics you see and use around you are thermosoftening polymers or thermoplastics, that is they can be remelted by heating them.  These plastics can be formed to an almost infinite number of shapes using processes like injection moulding or vacuum forming.  These materials originate from oil so we do need to make sure that we use plastics responsibly and recycle them wherever possible, to make the best use of this valuable and finite resource. 

The Titanium Age?

The metal titanium is used in a wide range of applications from jet engine components to artificial hip joints, and jewellery to sports equipment.  It is useful as it has a very high strength to weight ratio, it is relatively inert and is safe to use inside the human body.  Titanium is used in a wide variety of artificial body parts, including replacement joints, heart valve cages and dental implants.  Around a 1000 tonnes of titanium are used every year in the manufacture of hip joints which have helped to improve the quality of life of millions of people!

The Carbon Age?

Carbon forms more compounds than any other element, over 10 million!  It is also special as it can form different allotropes, that is there are different ways that carbon atoms can arrange themselves which result in stable material. Graphite and diamond have both been around for a long time and have surprisingly different properties considering they are made from the same stuff! Graphite is very soft (it can be used as a lubricant) and will conduct electricity, whilst diamond is the hardest natural substance known and is an electrical insulator. Carbon atoms can also form themselves into balls or tubes and carbon nanotubes may provide some very exciting construction materials for the future. Carbon fibres composites are now commonly used in sports equipment, where they have helped to improve the performance of professional and amateur athletes.

There are countless other materials that have helped to change the technology that we rely on, take another look around you and see if you can identify the materials that have shaped the world around you!

If you would like to find out more about materials and how you can help to develop the material world of the future please contact Dr Diane Aston, the Education Co-ordinator for the Institute of Materials, Minerals and Mining by e-mailing diane.aston@iom3.org, or visit our web-sites www.iom3.org or
www.materials-careers.org.uk.