Nav: Home

Microscale superlubricity could pave way for future improved electromechanical devices

August 01, 2018

Lubricity measures the reduction in mechanical friction and wear by a lubricant. These are the main causes of component failure and energy loss in mechanical and electromechanical systems. For example, one-third of the fuel-based energy in vehicles is expended in overcoming friction. So superlubricity -- the state of ultra-low friction and wear -- holds great promise for the reduction of frictional wear in mechanical and automatic devices.

A new joint Tel Aviv University/Tsinghua University study finds that robust structural superlubricity can be achieved between dissimilar, microscale-layered materials under high external loads and ambient conditions. The researchers found that microscale interfaces between graphite and hexagonal boron nitride exhibit ultra-low friction and wear. This is an important milestone for future technological applications in space, automotive, electronics and medical industries.

The research is the product of a collaboration between Prof. Oded Hod and Prof. Michael Urbakh of TAU's School of Chemistry; and Prof. Ming Ma and Prof. Quanshui Zheng of Tsinghua University's Department of Mechanical Engineering and their colleagues. It was conducted under the auspices of the joint TAU-Tsinghua collaborative XIN Center and was published in Nature Materials on July 30. The paper can be found at https://www.nature.com/articles/s41563-018-0144-z.

Enormous implications for computer and other devices

The new interface is six orders of magnitude larger in surface area than earlier nanoscale measurements and exhibits robust superlubricity in all interfacial orientations and under ambient conditions.

"Superlubricity is a highly intriguing physical phenomenon, a state of practically zero or ultra-low friction between two contacting surfaces," says Prof. Hod. "The practical implications of achieving robust superlubricity in macroscopic dimensions are enormous. The expected energy savings and wear prevention are huge."

"This discovery may lead to a new generation of computer hard discs with a higher density of stored information and enhanced speed of information transfer, for example," adds Prof. Urbakh. "This can be also used in a new generation of ball bearing to reduce rotational friction and support radial and axial loads. Their energy losses and wear will be significantly lower than in existing devices."

The experimental part of the research was performed using atomic force microscopes at Tsinghua and the fully atomistic computer simulations were completed at TAU. The researchers also characterized the degree of crystallinity of the graphitic surfaces by conducting spectroscopy measurements.

Close collaboration

The study arose from an earlier prediction by theoretical and computational groups at TAU that robust structural superlubricity could be achieved by forming interfaces between the materials graphene and hexagonal boron nitride. "These two materials are currently in the news following the 2010 Nobel Prize in Physics, which was awarded for groundbreaking experiments with the two-dimensional material graphene. Superlubricity is one of their most promising practical applications," says Prof. Hod.

"Our study is a tight collaboration between TAU theoretical and computational groups and Tsinghua's experimental group," says Prof. Urbakh. "There is a synergic cooperation between the groups. Theory and computation feed laboratory experiments that, in turn, provide important realizations and valuable results that can be rationalized via the computational studies to refine the theory."

The research groups are continuing to collaborate in this field studying the fundamentals of superlubricity, its extensive applications and its effect in ever larger interfaces.
-end-
American Friends of Tel Aviv University supports Israel's most influential, comprehensive and sought-after center of higher learning, Tel Aviv University (TAU). TAU is recognized and celebrated internationally for creating an innovative, entrepreneurial culture on campus that generates inventions, startups and economic development in Israel. TAU is ranked ninth in the world, and first in Israel, for producing start-up founders of billion-dollar companies, an achievement that surpassed several Ivy League universities. To date, 2,500 US patents have been filed by Tel Aviv University researchers -- ranking TAU #1 in Israel, #10 outside of the US and #43 in the world.

American Friends of Tel Aviv University

Related Mechanical Engineering Articles:

'Melting rock' models predict mechanical origins of earthquakes
Engineers at Duke University have devised a model that can predict the early mechanical behaviors and origins of an earthquake in multiple types of rock.
Mechanical force as a new way of starting chemical reactions
Researchers have shown mechanical force can start chemical reactions, making them cheaper, more broadly applicable, and more environmentally friendly than conventional methods.
Molecular nanocarbons with mechanical bonds
Scientists at Nagoya University have succeeded in synthesizing molecular nanocarbons with knots and catenanes by using a novel method in which silicon atoms are used.
Mechanical forces control cell fate during brain formation
The study shows that during the embryonic development of the brain, the cells that are between adjacent segments detect the mechanical forces generated during morphogenesis to regulate the balance between progenitor stem cells and differentiated neurons.
Mechanical vibration generated by electron spins
Micro mechanical elements are indispensable components of modern electrical devices but the actuation of them requires electrical current.
Machine learning predicts mechanical properties of porous materials
Machine learning can be used to predict the properties of a group of materials which, according to some, could be as important to the 21st century as plastics were to the 20th.
Converting biomass by applying mechanical force
German nanoscientists have succeeded in demonstrating a new reaction mechanism to cleave cellulose efficiently.
Study unfolds a new class of mechanical devices
In a paper published today in Science Robotics, engineers at Brigham Young University detail new technology that allows them to build complex mechanisms into the exterior of a structure without taking up any actual space below the surface.
NRL demonstrates new non-mechanical laser steering technology
Steerable electro-evanescent optical refractor (SEEOR) chips take laser light in the mid-wavelength infrared (MWIR) as an input and steers the beam at the output in two dimensions without the need for mechanical devices.
Mussel-inspired defect engineering enhances the mechanical strength of graphene fibers
Researchers demonstrated the mussel-inspired reinforcement of graphene fibers for the improvement of different material properties.
More Mechanical Engineering News and Mechanical Engineering Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Uncharted
There's so much we've yet to explore–from outer space to the deep ocean to our own brains. This hour, Manoush goes on a journey through those uncharted places, led by TED Science Curator David Biello.
Now Playing: Science for the People

#556 The Power of Friendship
It's 2020 and times are tough. Maybe some of us are learning about social distancing the hard way. Maybe we just are all a little anxious. No matter what, we could probably use a friend. But what is a friend, exactly? And why do we need them so much? This week host Bethany Brookshire speaks with Lydia Denworth, author of the new book "Friendship: The Evolution, Biology, and Extraordinary Power of Life's Fundamental Bond". This episode is hosted by Bethany Brookshire, science writer from Science News.
Now Playing: Radiolab

Dispatch 2: Every Day is Ignaz Semmelweis Day
It began with a tweet: "EVERY DAY IS IGNAZ SEMMELWEIS DAY." Carl Zimmer – tweet author, acclaimed science writer and friend of the show – tells the story of a mysterious, deadly illness that struck 19th century Vienna, and the ill-fated hero who uncovered its cure ... and gave us our best weapon (so far) against the current global pandemic. This episode was reported and produced with help from Bethel Habte and Latif Nasser. Support Radiolab today at Radiolab.org/donate.