UPV/EHU-University of the Basque Country's researchers have explored superelasticity properties on a nanometric scale based on shearing an alloy's pillars down to nanometric size
UPV/EHU-University of the Basque Country's researchers have explored superelasticity properties on a nanometric scale based on shearing an alloy's pillars down to nanometric size. In the article published by the prestigious scientific journal Nature Nanotechnology, the researchers have found that below one micron in diameter the material behaves differently and requires much higher stress for it to be deformed. This superelastic behaviour is opening up new channels in the application of microsystems involving flexible electronics and microsystems that can be implanted into the human body.
Superelasticity is a physical property by which it is possible to deform a material to a considerable extent, up to 10%, which is much higher than that of elasticity. So when stress is applied to a straight rod, the rod can form a U-shape and when the stress applied is removed, the rod fully regains its original shape. Although this has been amply proven in macroscopic materials, "until now no one had been able to explore these superelasticity properties in micrometric and nanometric sizes," explained José María San Juan, lead researcher of the article published by Nature Nanotechnology and a UPV/EHU professor.
Researchers in the UPV/EHU's Department of Condensed Matter Physics and Applied Physics II have managed to see that "the superelastic effect is maintained in really small devices in a copper-aluminium-nickel alloy". It is an alloy with shape memory on which the research team has been working for over 20 years on a macroscopic level: Cu-14Al-4Ni, an alloy that displays superelasticity in ambient temperature.
By using a piece of equipment known as a Focused Ion Beam, "an ion cannon that acts as a kind of atomic knife that shears the material", explained San Juan, they built micropillars and nanopillars of this alloy with diameters ranging between 2 μm and 260 nm --a micrometre is one millionth of a metre and a nanometre one thousand-millionth of a metre--. And to them they applied a stress using a sophisticated instrument known as a nanoindenter, which "allows extremely small forces to be applied," and then they measured their behaviour.
The researchers have for the first time confirmed and quantified that in diameters of less than a micrometre there is a considerable change in the properties relating to the critical stress for superelasticity. "The material starts to behave differently and needs a much higher stress for this to take place. The alloy continues to display superelasticity but for much higher stresses". San Juan highlights the novelty of this increase in critical stress linked to size, and also stresses that they have been able to explain the reason for this change in behaviour: "We have proposed an atomic model that allows one to understand why and how the atomic structure of these pillars changes when a stress is applied".
Microsystems involving flexible electronics and devices that can be implanted in the human body
The UPV/EHU professor highlighted the importance of this discovery, "spectacular superelastic behaviour on a small scale", which opens up new channels in the design of strategies for applying alloys with shape memory to develop flexible microsystems and electromechanical nanosystems. "Flexible electronics is very much present on today's market, it is being increasingly used in garments, sports footwear, in various displays, etc." He also affirmed that all this is of crucial importance in developing smart healthcare devices of the Lab-on-a-chip type that can be implanted into the human body. "It will be possible to build tiny micropumps or microactuators that can be implanted on a chip, and which will allow a substance to be released and regulated inside the human body for a range of medical treatments."
It is a discovery that "is expected to have great scientific and technological repercussions and offer the potential to revolutionise various aspects in related fields," concluded San Juan, and he welcomed the fact that "we have managed to transfer all the necessary knowledge and to acquire the working tools that the most advanced centres can avail themselves of to open up a new line of research which can be fully developed at the UPV/EHU".
The UPV/EHU professor José María San Juan-Nuñez heads the Physical Metallurgy Group in the Department of Condensed Matter Physics in the UPV/EHU's Faculty of Science and Technology. The UPV/EHU's Department of Applied Physics II, the Department of Materials Science of the University of Cadiz, and CIC nanoGUNE collaborated in this research.
Jose F. Gómez-Cortés, Maria L. Nó, Iñaki López-Ferreño, Jesús Hernández-Saz, Sergio I. Molina, Andrey Chuvilin and Jose M. San Juan. "Size effect and scaling power-law for superelasticity in shape-memory alloys at the nanoscale". Nature Nanotechnology. May 2017. DOI: 10.1038/nnano.2017.91 http://rdcu.
Matxalen Sotillo | EurekAlert!
Graphene origami as a mechanically tunable plasmonic structure for infrared detection
25.04.2018 | University of Illinois College of Engineering
Scientists create innovative new 'green' concrete using graphene
24.04.2018 | University of Exeter
At the Hannover Messe 2018, the Bundesanstalt für Materialforschung und-prüfung (BAM) will show how, in the future, astronauts could produce their own tools or spare parts in zero gravity using 3D printing. This will reduce, weight and transport costs for space missions. Visitors can experience the innovative additive manufacturing process live at the fair.
Powder-based additive manufacturing in zero gravity is the name of the project in which a component is produced by applying metallic powder layers and then...
Physicists at the Laboratory for Attosecond Physics, which is jointly run by Ludwig-Maximilians-Universität and the Max Planck Institute of Quantum Optics, have developed a high-power laser system that generates ultrashort pulses of light covering a large share of the mid-infrared spectrum. The researchers envisage a wide range of applications for the technology – in the early diagnosis of cancer, for instance.
Molecules are the building blocks of life. Like all other organisms, we are made of them. They control our biorhythm, and they can also reflect our state of...
University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.
Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.
Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.
Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...
Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.
The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...
13.04.2018 | Event News
12.04.2018 | Event News
09.04.2018 | Event News
25.04.2018 | Physics and Astronomy
25.04.2018 | Physics and Astronomy
25.04.2018 | Information Technology