Energy can never be created or destroyed. Instead, we convert it from one form to another. We convert electrical energy to heat energy in our toasters and we convert wind energy to electrical energy using wind turbines. But what about the energy that our own bodies produce, is there an efficient way of harvesting it?
We eat our dinners, which are digested into their basic components (sugars, carbohydrates, proteins etc.) to produce chemical energy. We then convert this chemical energy into useful energy to go about our everyday lives.Unfortunately, much of this energy is wasted as heat. What if, instead of wasting it, we could harness it for something useful? Scientists have been trying to come up with ways in which we can use this heat energy to power very small bits of electrical equipment.
Almost 200 years ago, a physicist called Thomas Johann Seebeck discovered that when a circuit is made from two different metals, with each metal at a different temperature, it would be able to move the needle on a compass. This is due to Ampere’s Law, in which an electrical current can induce a magnetic field.
The temperature gradient across the two metal pieces created a difference in electrical potential across the device, which allowed an electrical current to flow within the closed circuit. This is what created a magnetic field to move the needle. The whole phenomenon is called thermoelectric power.
These devices are ideal for converting our body heat into useful energy. With one piece of metal in contact with our skin, and the other with the air, a significant temperature difference is measured and a current will flow! Scientists are now using this idea to create small devices which can monitor different aspects of our health.
In order to get the most out of these devices, materials need to be developed with certain characteristics. Material scientists can make materials from scratch, building them up one layer of atoms at a time. By controlling the manufacturing process, they can make something that does exactly what they want. Imagine devices that will monitor your heart and would never run out of power, and all you need to do is wear it.
Jamie Gallagher is one of these material scientists, his expertise lie in the making of these materials. He looks at different materials, and attempts to enhance certain characteristics, “I try to make them better. I grow materials on the nanometer scale”.
He is very passionate about his work and has good reasons for working in this field. By building up materials from the atomic scale he gets to explore an entirely different world, “a world that is unseen and almost unimaginable yet we can grow, then control them and make them work for us.”
His show, ‘Living in a Material World’ looks at the cutting edge research done in his lab at University of Glasgow. “We develop new materials which are used for renewable energy… Some of it might sound a little familiar like solar power and batteries but there are also more farfetched ideas like harnessing body heat! The development of new energy solutions is incredibly important. In our lives we consume so much energy, lighting, transport, heating- where can all this come from if we don’t have petrol and coal? Science is frantically trying to find out.”
Jamie Gallagher and his show will be in the Fraser Noble Building from 14:00 until 15:00 during the British Science Festival.
Julie Gould is the Science in Society Assistant for the British Science Association. She is starting the Science Communication MSc this autumn at Imperial College, London. She has a blog and you can follow her on Twitter @JuliePCGould.