A specialist microscope developed and built in Gloustershire is being used in new research that addresses one of the major hindrances to the wider exploitation of graphene: the difficulty in growing large defect-free films.
The Renishaw inVia Raman microscope is being used by an international team—led by Oxford University scientists Professor Nicole Grobert and Adrian Murdock— in collaboration with Renishaw and researchers from the Forschungszentrum Juelich in Germany and University of Ioannina in Greece to examine film thickness, strain and defects in graphene films.
Graphene is a single layer of carbon atoms and was the first two dimensional material to be discovered. It has very interesting electronic and mechanical properties; it is one of the most conductive materials known to science and has a breaking strength 100 times greater than steel.
Typically, when graphene is grown using chemical vapour deposition (CVD), the individual graphene flakes merge with a variety of different orientations, creating defects. In this work, titled ‘Controlling the Orientation, Edge Geometry and Thickness of Chemical Vapour Deposition Graphene’, and published in the journal ACS Nano, it was found that the orientation of the underlying copper substrate could be used to guide the graphene flakes so they are aligned, and these defects are prevented.
“The inVia Raman spectrometer is a very powerful tool for investigating the properties of graphene. This work gives a much better understanding of CVD graphene growth, which will be important for manufacturing graphene on an industrial scale,” said Dr Tim Batten, Raman applications specialist at Renishaw.
In 2006 Professor Andrea Ferrari (University of Cambridge), used a Renishaw Raman spectrometer to conduct the first Raman characterisation of graphene. He used samples from its discoverers, Nobel Prize winners Professor Andre Geim and Professor Kostya Novoselov (University of Manchester). Since then, researchers worldwide have used data from Renishaw Raman systems in hundreds of scientific papers on graphene, greatly assisting in the understanding and development of this amazing material.
Nemesis project to explore energy harvesting
The University of Bath has received £2.27m to create a new world-leading centre for energy harvesting and generation.
The Centre aims to create new piezoelectric and ferroelectric energy harvesting systems capable of converting mechanical vibrations into electrical energy, thermal fluctuations into electrical energy, sunlight into chemical and electrical energy, and vibrations into chemical energy.
Having a focus centre on energy harvesting can boost developments in clean tech, power systems and chip design, all of which are strong in the region.
“Setting up a world-leading research centre here in the UK will put us at the forefront of this increasingly important field of work,” said head of the new centre, Professor Chris Bowen. ” The new Centre brings together experts in from different disciplines, including materials, physics, chemistry and electrical engineering, offering an ideal environment in which to develop new and innovative solutions to generating and harvesting energy.”
One work stream in the Centre will look at novel materials that are capable of harvesting the vibrations of machines or vehicles and converting the energy into electricity. This electricity can then be used to power devices within a vehicle or machine, including damage sensors or consumer electronics.
Another stream aims to develop new methods for water splitting – separating water into hydrogen and oxygen. The process of splitting water to create clean-burning hydrogen fuel has long been the Holy Grail for clean energy advocates.
“As we continually strive to create safer and more efficient machines and vehicles, the need to power sensors that can safely sit in potentially very hot and hostile environments near the engine, where batteries would be unsafe or impractical, has increased,” said Bowen. “Clean energies are also a high priority for modern society, and through our research we aim to create nano-structured ferroelectric and piezoelectric materials that can be used to split water, creating clean, environmentally-friendly hydrogen fuel.”
“This is an increasingly important area of research and Professor Bowen’s unique expertise in piezoelectric and ferroelectric material, along with the University of Bath’s track-record of high impact materials research, has been recognised by the ERC in their decision to fund this Centre,” said Professor Jane Millar, Pro Vice Chancellor for Research.
The Centre will fund visiting researchers at the University, and interaction with other leading academics working in ferroelectrics and energy harvesting such as Prof. John Wang of NUS, Singapore and Prof. Vitaly Topolov of Rostov State University.
A smaller version of the Raspberry Pi computer built in South Wales is driving the cost to under $25 for portable and low cost media centres.
element14 has announced the launch of the new credit card sized Raspberry Pi Model A board in Europe, selling at under $25. It uses the same 700MHz ARM1176 Broadcom BCM2835 processor (Boradcom has a design centre in Bristol) but only 256MB of RAM is included as standard, there is no Ethernet connection and only one USB port, but it does use considerably less energy for battery-powered applications.
The larger Model B sold over 500,000 units and demand for the Model A board is anticipated to be from those making industrial control modules, from robotics, automation, and significantly, to use the Pi as a very cheap media centre.
In recent weeks element14 has launched two exclusive accessories to support the development of new applications and uses: The Gertboard, a flexible experimenter board that connects the Raspberry Pi out to the physical world, and PiFace, which allows the user to sense and control the real world. Both are available to buy to supplement activity on the Raspberry Pi and can be used with the Model A and Model B boards.
“The Model A board is the next item in the Raspberry Pi range to be manufactured exclusively in Wales by Sony in partnership with element14,” said Claire Doyle, Global Head of Raspberry Pi at element14. “Being a part of the Raspberry Pi revolution is something we are very proud of as computer science and programming skills are key to ensure future generations of design engineers.”
The Model A board costs $25 (£15.95) plus tax and shipping, and is available today through Farnell element14 in Europe and CPC in the UK and Ireland. Further countries will be added in the coming weeks.