Throughout history, materials and advances in material technology have influenced humankind. Now we might be on the verge of the next shift in this type of technology, enabling products and functions we never believed possible. By Mark Teague, Business and Communications Specialist at Sandvik Coromant.
Industry is demanding that materials be lighter, tougher, thinner, denser and more flexible or rigid, as well as heat- and wear-resistant. At the same time, researchers are pushing the boundaries of what we imagine is possible, seeking to improve and enhance existing materials and at the same time come up with completely new materials that, while years away from day-to-day use, take us down entirely new technological pathways.
Based on the research we’re seeing today, the field of applied material science is set to move in new, almost science-fiction-like directions. Looming resource scarcity is demanding innovations and out-of-the-box thinking. On the materials front, composites with desirable attributes such as low weight, high strength and high durability look likely to take a larger market share, and more of these materials will likely be based on renewable resources, as the need for this becomes greater. The most promising jewel in this arena is graphene.
Heading for the graphene revolution
Graphene is a single atom thick (a million times thinner than a human hair) but 200 times stronger than steel by weight, extremely flexible, super light and almost transparent, with great heat and electricity conductivity. In fact, researchers at Nankai University in Tianjin, China, recently found that a graphene sponge can turn light into energy, thus taking humankind one step closer to a fuel-free spacecraft, one that runs by the light of the sun.
Graphene was discovered almost accidentally when professors Andre Geim and Kostya Novoselov at the University of Manchester in the UK experimented with pencils and sticky tape in 2004. In 2010, Geim and Novoselov won the Nobel Prize in physics for their graphene research, and the European Union subsequently committed 1 billion euros to fund the Graphene Flagship, a research initiative aimed at speeding up the development of commercial applications.
Potential areas of application range from water purification and energy storage to household goods, computers and other electronics. Meanwhile, although graphene-related patents are increasing by the thousands, widespread industrial adoption of graphene is limited by the expense of producing it – but that may be about to change. Researchers at the University of Glasgow have found a way to produce large sheets of graphene at a cost some 100 times cheaper than the previous production method.
Synthetic skin, capable of providing sensory feedback to people with limb prostheses, is one of the many possibilities that could grow out of this development.
“Graphene could help provide an ultraflexible, conductive surface that could provide people with prosthetics capable of providing sensation in a way that is impossible for even the most advanced prosthetics today,” says Dr Ravinder Dahiya, who led the research team at the University of Glasgow.
The death of metals?
Metals have dominated industry, defining entire periods of human history. Such long-term use has created a wealth of information and expertise, but scientists and researchers continue to work to extend the boundaries of these materials. Nanomaterials figure prominently in this research, enhancing metals and opening up new application areas. Developments in metal matrix nanocomposites – composites that partially consist of carbon nanotubes or nanoparticles – could usher in a new era of weight reduction in the aerospace industries, with added strength and stiffness.
If it’s broken, let it fix itself
Nanocomposite research is opening up the possibility of materials that fix themselves, much the way the human body heals itself. Researchers at the Beckman Institute’s Autonomous Materials Systems Group at the University of Illinois in the US are working on fibre-composite materials with self-healing properties that involve the integration of healing agents that are released to mix and polymerise when a defect is detected.
“Materials that heal themselves are coming,” says material scientist Mark Miodownik. For now, what’s technically possible isn’t close to being reasonable economically, but the possibility of fixing anything on the fly, from airplane wings to bike frames to car parts crucial to the safety of vehicle and passengers, is on the horizon. And it will have massive impact on product development, life cycle and sustainability. Researchers are even working on materials that will allow a roadway to repair itself instead of waiting for an overworked, understaffed maintenance crew.
Outperforming nature
For thousands of years, material science moved forward through a series of accidental discoveries of materials that existed in nature. Today researchers are looking beyond what’s in the natural world, combining multiple conventional materials or parts of materials and focusing on the inherent structure or pattern, to create properties that do not exist in nature – or at least haven’t been discovered thus far.
One such development is an arrangement of ridges formulated to resemble a shark’s skin. The micropattern, named Sharklet, protects against the harboring and transmission of bacteria and is being developed for use in hospital and health-care settings.
Another materials development involves invisibility. Physicists in several countries are working on metamaterials that hold the promise of rendering objects invisible by cloaking them with a material that can bend the electromagnetic radiation, such as light, around an object, creating the illusion that it isn’t really there.
Material science and the development of new materials, as well as improvement of existing ones, look likely to play a crucial role in such areas as resource scarcity and sustainability. New materials – for example, light-absorbing building materials – could help counter global warming.
We seem to be on the verge of a new age, characterised not only by digitalisation and the Internet of Things but also, importantly, by new materials – materials that can make our future easier, safer and more sustainable. The sky really is the limit.