Monday, December 6, 2021

    Latest Posts

    Magnetene – A Graphene-Like 2D Material – Leverages Quantum Effects To Achieve Ultra-Low Friction

    Magneten may have useful applications as a lubricant for embedded devices or other microelectromechanical systems.

    A team of researchers at the University of Toronto’s Faculty of Engineering and Rice University have reported the first measurements of ultra-low friction behavior in a material known as magnetene. The results show the way to strategies for designing similar low-friction materials for use in a variety of areas, including small embedded devices.

    Magneten is a 2D material, meaning that it is composed of a single layer of atoms.In this respect it is similar to Graphene, A material that has been intensively studied for its anomalous properties, including ultra-low friction, since its discovery in 2004.

    “Most 2D materials are formed as flat sheets,” said Peter Serles, a PhD candidate who is the lead author of a new paper published on November 17, 2021. Science Advances..

    “Theory was that these graphene sheets were only very weakly coupled, so they had low frictional behavior and were slippery to each other. You can imagine it’s like fanning out a deck of playing cards. The friction is so small that it doesn’t take much effort to unfold the deck. “

    Peter Cellless Magneten Atomic Force Microscope

    PhD candidate Peter Cellless places a sample of magnesium in an atomic force microscope. New measurements and simulations of this material show that its low friction behavior is due to quantum effects.Credits: Daria Perevezentsev / University of Toronto Faculty of Engineering

    A team that includes Professor Tobin Fillerter and Professor Chandra Veer Singh, Post-Doc Shwetank Yadav, and several current and graduates of the Lab Group wanted to test this theory by comparing graphene to other 2D materials.

    Graphene is made of carbon, while magnetite is made of magnetite, a type of iron oxide, and usually exists as a 3D lattice. Collaborators from the Rice University team used high-frequency sound waves to process 3D magnetite and carefully separated layers consisting of only a few pieces of 2D magnetite.

    Next, the engineering team at the University of Toronto put the magneten sheet into an atomic force microscope. In this device, a sharp-tipped probe is dragged onto the top of the magneten sheet to measure friction. This process is comparable to how a record player stylus is dragged across the surface of a vinyl record.

    “The bond between the layers of magneten is much stronger than the bond between the stacks of graphene sheets,” says Serles. “They don’t slip through each other. What surprised us was the friction between the tip of the probe and the top slice of magneten, which was as low as graphene.”


    This schematic shows the lattice structure of a cubic. The dark red spheres represent iron and the bright red spheres represent oxygen.Credits: Shwetank Yadav / University of Toronto Faculty of Engineering

    So far, scientists have attributed the low friction of graphene and other 2D materials to the theory that the sheet can slide because it is bound only by a weak force known as the van der Waals force. However, the low friction behavior of magnetene, which does not show these forces due to its structure, suggests that something else is happening.

    “When we move from 3D materials to 2D materials, the effects of quantum physics begin to cause a lot of anomalies,” says Serles. “Depending on the angle at which the slice is cut, it can be very smooth or very coarse. Atoms are no longer restricted in their three dimensions, so they can vibrate in different ways, and also the electronic structure. It changes. It turns out that all of this together affects friction. “

    The team confirmed the role of these quantum phenomena by comparing the experimental results with those predicted by computer simulations. Yadav and Singh built a mathematical model based on density functional theory to simulate the behavior of a probe tip sliding over a 2D material. Models incorporating quantum effects were the best predictors of experimental observations.

    Serles states that the practical result of the team’s findings is to provide new information to scientists and engineers who want to deliberately design ultra-low friction materials. Such materials can serve as a lubricant for a variety of small applications, including embedded devices.

    For example, you can imagine a small pump that delivers a controlled amount of a particular drug to a particular part of the body. Other types of microelectromechanical systems collect energy from the beating heart to power sensors, or power small robotic manipulators that can classify one type of cell in a Petri dish from another. It can be supplied.

    “When dealing with such small moving parts, the surface area to mass ratio is very high,” said Filletter, the corresponding author of the new study. “That is, things are much more likely to get stuck. What we have shown in this work is that the friction of these 2D materials is so small because of their very small scale. . These quantum effects do not apply to larger 3D materials. “

    Serles states that these scale-dependent effects, coupled with the fact that iron oxide is non-toxic and inexpensive, make magnesium very attractive for use in implantable machinery. But he adds that there is more work to be done before the behavior of the quantum is fully understood.

    “I’ve tried this with other types of iron-based 2D materials such as hematen and chromiten, but I don’t see the same quantum properties and low friction behavior,” he says. “Therefore, we need to focus on why these quantum effects are occurring, which allows us to be more deliberate about the design of new types of low friction materials.”

    Reference: By Peter Cellless, Tyve Arif, Anand B. Petillas, Shwetank Yadaf, Guolui Wan, Ten Cuy, Arabind Petitlas Balan, Takul Prasad Yadav, Prasankumar Tibeolchu, Nisia Chakingal “Magnetene Friction, Non-Van der Waals 2D Material”, Gelu Costin, Chandra Veer Singh, Pulickel M. Ajayan, Tobin Filleter, November 17, 2021 Science Advances..
    DOI: 10.1126 / sciadv.abk2041

    (function(d, s, id){
    var js, fjs = d.getElementsByTagName(s)[0];
    if (d.getElementById(id)) return;
    js = d.createElement(s); = id;
    js.src = “//”;
    fjs.parentNode.insertBefore(js, fjs);
    }(document, ‘script’, ‘facebook-jssdk’));

    Magnetene – A Graphene-Like 2D Material – Leverages Quantum Effects To Achieve Ultra-Low Friction Source link Magnetene – A Graphene-Like 2D Material – Leverages Quantum Effects To Achieve Ultra-Low Friction

    The post Magnetene – A Graphene-Like 2D Material – Leverages Quantum Effects To Achieve Ultra-Low Friction appeared first on California News Times.

    Source link

    Latest Posts

    Don't Miss

    Stay in touch

    To be updated with all the latest news, offers and special announcements.