Self-healing gold particlesSeptember 14, 2017
Self-healing materials are able to repair autonomously defects, such as scratches, cracks or dents, and resume their original shape. For this purpose, they must be composed of several components whose combined properties result in the desired characteristics. Scientists of the Karlsruhe Institute of Technology (KIT) and the Technion - Israel Institute of Technology now discovered that also tiny particles of pure gold have surprising self-healing capacities.
Lending shape memory to materials is a very complex, painstaking effort. In pure metals, self-healing capacities repairing mechanically caused defects so far have been considered impossible. However, they have now been observed by scientists in pure gold. This is reported in the Advanced Science journal.
"The search for materials of this kind so far has been concentrated on polymers made up of many components and complicated structures," states Christian Brandl of the Institute for Applied Materials - Materials and Biomechanics (IAM-WBM). Their self-healing powers were all based on the collective transformation of the phases of one or more materials making them up. This is caused, for instance, by heating, melting or precipitation, which may change materials properties. In metal alloys, the shape memory effect is based on the phenomenon that they can exist in two different crystal structures as a function of a specific temperature. When this is changed, the metals "remember" their former shape they had at that respective temperature. However, this self-healing effect is never complete in composites or in alloys.
Self-healing or shape memory in pure metals was entirely unknown before. This effect is precisely what a group of scientists around Dr. Christian Brandl (KIT) and Eugen Rabkin of the Technion - Israel Institute of Technology now observed in gold particles. These multi-shaped particles resumed their individual original shapes almost completely. There was no deformation of any kind. "The fascinating thing about this is that the restored particle shapes did not correspond to that with the lowest surface energy, as would have been expected," says Brandl.
The scientists had produced mechanical defects in the particles first in simulations by high-power computers and then, in reality, with the measurement tip of a scanning force microscope. They found that annealing air temperatures far below the melting temperature of gold caused gold atoms to move along surface steps back into the dents, refilling them almost completely. Such surface steps occur in many deformed metals. Consequently, Brandl expects also other metals to have the self-healing properties observed here. The scientists anti-cipate that their findings will allow robust components for structures smaller than one thousandth of a millimeter to be designed.
Video description: The video shows how, in molecular dynamics simulation, heating of the deformation first applied (dent) produces random movements of the gold atoms (so-called diffusion) slowly healing back into the original shape. The atoms are stained as a function of their height. In the smaller window, those atoms are darkest which moved over the longest distance, which shows that the atoms move along the surface steps.
For further information, please contact: Dr. Felix Mescoli, Press Officer, Phone: +49 721 608-48120, Fax: +49 721 608-43658, Email: firstname.lastname@example.org
Being „The Research University in the Helmholtz-Association", KIT creates and imparts knowledge for the society and the envi-ronment. It is the objective to make significant contributions to the global challenges in the fields of energy, mobility and infor-mation. For this, about 9,300 employees cooperate in a broad range of disciplines in natural sciences, engineering sciences, economics, and the humanities and social sciences. KIT pre-pares its 26,000 students for responsible tasks in society, indus-try, and science by offering research-based study programs. In-novation efforts at KIT build a bridge between important scien-tific findings and their application for the benefit of society, eco-nomic prosperity, and the preservation of our natural basis of life.
Since 2010, the KIT has been certified as a family-friendly university.
This press release is available on the internet at http://www.sek.kit.edu/presse.php
Karlsruher Institut für Technologie (KIT)
Related Technology Articles:
More use of technology led to increases in attention, behavior and self-regulation problems over time for adolescents already at risk for mental health issues, a new study from Duke University finds.
The transfer of technology brings ideas closer to commercialization. The transformation happens in several steps, such as invention, innovation, building prototypes, production, market introduction, market expansion, after sales services.
Imagine patterning and visualizing silicon at the atomic level, something which, if done successfully, will revolutionize the quantum and classical computing industry.
Pioneering research by Professor Paul Lewis of Swansea University's Medical School into one of the most common lung diseases in the UK, Chronic Obstructive Pulmonary Disease, has led to the development of a new technology that can quickly and easily diagnose and monitor the condition.
Tecnalia leads EFFIPRO (Energy EFFIcient PROcess of Engineering Materials) project, which shows a new manufacturing process using powder metallurgy.
A team of researchers at Friedrich-Alexander-Universität have achieved an important milestone in the quest to develop efficient solar technology as an alternative to fossil fuels.
For this episode of BioScience Talks, we're joined by Gene Drive Committee co-chair James P.
The same technology used by the entertainment industry to animate characters such as Gollum in 'The Lord of The Rings' films, will be used to help train elite athletes, for medical diagnosis and even to help improve prosthetic limb development, in a new research center at the University of Bath launched today.
Carbon capture and storage could be used to mitigate greenhouse gas emissions and thus ameliorate their impact on climate change.
It has been thought technically difficult to achieve projection mapping onto a moving/rotating object so that images look as though they are fixed to the object.
Related Technology Reading:
Irresistible: The Rise of Addictive Technology and the Business of Keeping Us Hooked
by Adam Alter (Author)
“One of the most mesmerizing and important books I’ve read in quite some time. Alter brilliantly illuminates the new obsessions that are controlling our lives and offers the tools we need to rescue our businesses, our families, and our sanity.” —Adam Grant, New York Times bestselling author of Originals and Give and Take
Welcome to the age of behavioral addiction—an age in which half of the American population is addicted to at least one behavior. We obsess over our emails, Instagram likes, and Facebook feeds; we binge on TV episodes... View Details
Radical Technologies: The Design of Everyday Life
by Adam Greenfield (Author)
A field manual to the technologies that are transforming our lives
Everywhere we turn, a startling new device promises to transfigure our lives. But at what cost? In this urgent and revelatory excavation of our Information Age, leading technology thinker Adam Greenfield forces us to reconsider our relationship with the networked objects, services and spaces that define us. It is time to re-evaluate the Silicon Valley consensus determining the future.
We already depend on the smartphone to navigate every aspect of our existence. We’re told that innovations—from... View Details
Soonish: Ten Emerging Technologies That'll Improve and/or Ruin Everything
by Kelly Weinersmith (Author), Zach Weinersmith (Author)
The instant New York Times bestseller!
A Wall Street Journal Best Science Book of the Year!
A Popular Science Best Science Book of the Year!
From a top scientist and the creator of the hugely popular web comic Saturday Morning Breakfast Cereal, a hilariously illustrated investigation into future technologies -- from how to fling a ship into deep space on the cheap to 3D organ printing
What will the world of tomorrow be like? How does progress happen? And why do we not have a lunar... View Details
New Dark Age: Technology and the End of the Future
by James Bridle (Author)
As the world around us increases in technological complexity, our understanding of it diminishes. Underlying this trend is a single idea: the belief that our existence is understandable through computation, and more data is enough to help us build a better world.
In actual fact, we are lost in a sea of information, increasingly divided by fundamentalism, simplistic narratives, conspiracy theories, and post-factual politics. Meanwhile, those in power use our lack of understanding to further their own interests. Despite the accessibility of information, we’re living in a new... View Details
Technology: A Reader for Writers
by Johannah Rodgers (Author)
Read. Write. Oxford.
Technology: A Reader for Writers focuses on the timely and vital subject of information and communications technologies and presents a range of contemporary and classic articles that invite students to consider and engage with questions related to how, why, and in what ways we may be able to critically reflect on ourselves and societies by writing and thinking about technology. Accompanied by group-discussion questions and writing prompts that ask students to engage with many of the same information and communications technologies they are... View Details
Technology: A World History (New Oxford World History)
by Daniel R. Headrick (Author)
Today technology has created a world of dazzling progress, growing disparities of wealth and poverty, and looming threats to the environment. Technology: A World History offers an illuminating backdrop to our present moment--a brilliant history of invention around the globe. Historian Daniel R. Headrick ranges from the Stone Age and the beginnings of agriculture to the Industrial Revolution and the electronic revolution of the recent past. In tracing the growing power of humans over nature through increasingly powerful innovations, he compares the evolution of technology in different... View Details
Bitcoin and Cryptocurrency Technologies: A Comprehensive Introduction
by Arvind Narayanan (Author), Joseph Bonneau (Author), Edward Felten (Author), Andrew Miller (Author), Steven Goldfeder (Author)
Bitcoin and Cryptocurrency Technologies provides a comprehensive introduction to the revolutionary yet often misunderstood new technologies of digital currency. Whether you are a student, software developer, tech entrepreneur, or researcher in computer science, this authoritative and self-contained book tells you everything you need to know about the new global money for the Internet age.
How do Bitcoin and its block chain actually work? How secure are your bitcoins? How anonymous are their users? Can cryptocurrencies be regulated? These are some of the many questions this... View Details
The Technology Tail: A Digital Footprint Story (Communicate with Confidence)
by Julia Cook (Author), Anita DuFalla (Illustrator)
A cute, creative story about children and their texts, tweets, posts and pics. Don t be mean and irresponsible! That s the straight-to-the-point advice Screen has for young readers who are active on social media. Whether tapping out messages on their computers, tablets or phones, Screen wants kids to know their words will follow them for life, creating a digital trail that can't be erased. A timeless message to a new generation just learning how to navigate the fast-changing digital age. Written for children in grades 1-6, this storybook uses rhymes and colorful illustrations to grab their... View Details
Refrigeration and Air Conditioning Technology (MindTap Course List)
by John Tomczyk (Author), Eugene Silberstein (Author), Bill Whitman (Author), Bill Johnson (Author)
Develop the knowledge and skills you need to maintain and troubleshoot today's complex heating, air conditioning, and refrigeration systems with REFRIGERATION AND AIR CONDITIONING TECHNOLOGY, 8th Edition. This practical, easy-to-understand book provides hands-on guidance, practical applications, and the solid foundation you need to fully understand today's HVAC service and repair, its environmental challenges, and their solutions. Focused on sustainable technology in today's HVAC/R industry with an emphasis on new technologies and green awareness, the 8th Edition covers the latest advances in... View Details
Engineering: An Illustrated History from Ancient Craft to Modern Technology (100 Ponderables)
by Tom Jackson (Editor) (Author), Tom Jackson (Editor)
From ancient aqueducts to soaring skyscrapers, explore engineering milestones over the centuries.
Combining engaging text with captivating images and helpful diagrams, renowned science writer Tom Jackson guides readers through the history of Engineering in the 7th installment of the groundbreaking PonderablesTM series.
Engineering is all around us. From our bridges, tunnels and skyscrapers, to our cars, computers and smartphones, engineering shapes our world and influences just about everything we see and do. And it s been that way for longer than you might think. From the... View Details