Posted in chemistry, nanotechnology, robotics/AI
Rapid progress has been made in recent years to build these tiny machines, thanks to supramolecular chemists, chemical and biomolecular engineers, and nanotechnologists, among others, working closely together. But one area that still needs improvement is controlling the movements of swarms of molecular robots, so they can perform multiple tasks simultaneously.
Researchers at Empa and EPFL have created one of the smallest motors ever made. It’s composed of just 16 atoms, and at that tiny size it seems to function right on the boundary between classical physics and the spooky quantum realm.
Like its macroscopic counterparts, this mini motor is made up of a moving part (the rotor) and a fixed part (the stator). The stator in this case is a cluster of six palladium atoms and six gallium atoms arranged in a rough triangular shape. Meanwhile, the rotor is a four-atom acetylene molecule, which rotates on the surface of the stator. The whole machine measures less than a nanometer wide.
The molecular motor can be powered by either thermal or electrical energy, although the latter was found to be much more useful. At room temperature, for example, the rotor was found to rotate back and forth at random. But when an electric current was applied using an electron scanning microscope, the rotor would spin in one direction with a 99-percent stability.
A research team from Empa and EPFL has developed a molecular motor which consists of only 16 atoms and rotates reliably in one direction. It could allow energy harvesting at the atomic level. The special feature of the motor is that it moves exactly at the boundary between classical motion and quantum tunneling — and has revealed puzzling phenomena to researchers in the quantum realm.
The smallest motor in the world—consisting of just 16 atoms: this was developed by a team of researchers from Empa and EPFL. “This brings us close to the ultimate size limit for molecular motors,” explains Oliver Gröning, head of the Functional Surfaces Research Group at Empa. The motor measures less than one nanometer—in other words it is around 100,000 times smaller than the diameter of a human hair.
In principle, a molecular machine functions in a similar way to its counterpart in the macro world: it converts energy into a directed movement. Such molecular motors also exist in nature—for example in the form of myosins. Myosins are motor proteins that play an important role in living organisms in the contraction of muscles and the transport of other molecules between cells.
Circa 2015
Move over, graphene — you’re not the only miracle material in town. Australian researchers have discovered that diamond nanothreads (one-dimensional diamond crystals capped with hydrogen) could be extremely strong. While scientists thought they were brittle when announced just a month ago, it turns out that they become supremely flexible (and thus durable) when you introduce the right kinds of defects. You could create nanoscopic structures that are just as strong as you need them to be, with a ‘perfect’ mix of bendy and rigid shapes.
The next major revolution in computer chip technology is now a step closer to reality. Researchers have shown that carbon nanotube transistors can be made rapidly in commercial facilities, with the same equipment used to manufacture traditional silicon-based transistors – the backbone of today’s computing industry.
The ability to restore sight to the blind is one of the most profound acts of healing medicine can achieve, in terms of the impact on the affected patient’s life — and one of the most difficult for modern medicine to achieve. We can restore vision in a limited number of scenarios and there are some early bionic eyes on the market that can restore limited vision in very specific scenarios. Researchers may have taken a dramatic step towards changing that in the future, with the results of a new experiment to design a bionic retina.
The research team in question has published a paper in Nature detailing the construction of a hemispherical retina built out of high-density nanowires. The spherical shape of the retina has historically been a major challenge for biomimetic devices.
A technological advancement that may prove crucial in the long-term success of dental implants has been developed by University of Queensland researchers.
Dr. Karan Gulati, NHMRC Early Career Fellow from the UQ School of Dentistry, said modifying dental implants with ‘nanopores’ will help protect against one of the leading causes of implant failure.
“Poor integration between the implant and the surrounding tissue is one of the leading causes of dental implant failure,” Dr. Gulati said. “If the sealing between the implant and the surrounding gum tissue fails it can result in bacteria entering the implant and causing infection.”
Researchers at the Nanoscience Center and at the Faculty of Information Technology at the University of Jyväskylä in Finland have demonstrated that new distance-based machine learning methods developed at the University of Jyväskylä are capable of predicting structures and atomic dynamics of nanoparticles reliably. The new methods are significantly faster than traditional simulation methods used for nanoparticle research and will facilitate more efficient explorations of particle-particle reactions and particles’ functionality in their environment. The study was published in a Special Issue devoted to machine learning in the Journal of Physical Chemistry on May 15, 2020.
The new methods were applied to ligand-stabilized metal nanoparticles, which have been long studied at the Nanoscience Center at the University of Jyväskylä. Last year, the researchers published a method that is able to successfully predict binding sites of the stabilizing ligand molecules on the nanoparticle surface. Now, a new tool was created that can reliably predict potential energy based on the atomic structure of the particle, without the need to use numerically heavy electronic structure computations. The tool facilitates Monte Carlo simulations of the atom dynamics of the particles at elevated temperatures.
Potential energy of a system is a fundamental quantity in computational nanoscience, since it allows for quantitative evaluations of system’s stability, rates of chemical reactions and strengths of interatomic bonds. Ligand-stabilized metal nanoparticles have many types of interatomic bonds of varying chemical strength, and traditionally the energy evaluations have been done by using the so-called density functional theory (DFT) that often results in numerically heavy computations requiring the use of supercomputers. This has precluded efficient simulations to understand nanoparticles’ functionalities, e.g., as catalysts, or interactions with biological objects such as proteins, viruses, or DNA. Machine learning methods, once trained to model the systems reliably, can speed up the simulations by several orders of magnitude.
Brilliantly colored chameleons, butterflies, opals—and now some 3D-printed materials—reflect color by using nanoscale structures called photonic crystals.
A new study that demonstrates how a modified 3D-printing process provides a versatile approach to producing multiple colors from a single ink is published in the journal Science Advances.
Some of the most vibrant colors in nature come from a nanoscale phenomenon called structural coloration. When light rays reflect off these periodically placed structures located in the wings and skins of some animals and within some minerals, they constructively interfere with each other to amplify certain wavelengths and suppress others. When the structures are well ordered and small enough—about a thousand times smaller than a human hair, the researchers said—the rays produce a vivid burst of color.
Mobile phones and computers are currently responsible for up to 8% of the electricity use in the world. This figure has been doubling each past decade but nothing prevents it from skyrocketing in the future. Unless we find a way for boosting energy efficiency in information and communications technology, that is. An international team of researchers, including Ikerbasque Research Associate Alexey Nikitin (DIPC), has just published in Nature 1 a breakthrough in quantum physics that could deliver exactly that: electronics and communications technology with ultralow energy consumption.
Future information and communication technologies will rely on the manipulation of not only electrons but also of light at the nanometer-scale. Squeezing light to such a small size has been a major goal in nanophotonics for many years. Particularly strong light squeezing can be achieved with polaritons, quasiparticles resulting from the strong coupling of photons with a dipole-carrying excitation, at infrared frequencies in two-dimensional materials, such as graphene and hexagonal boron nitride. Polaritons can be found in materials consisting of two-dimensional layers bound by weak van der Waals forces, the so-called van der Waals materials. These polaritons can be tuned by electric fields or by adjusting the material thickness, leading to applications including nanolasers, tunable infrared and terahertz detectors, and molecular sensors.
But there is a major problem: even though polaritons can have long lifetimes, they have always been found to propagate along all directions (isotropic) of the material surface, thereby losing energy quite fast, which limits their application potential.
