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Posts Tagged ‘Chemistry’

Astronomy,Chemistry,Physics

Conversations in the Clean Room

At the shared laboratories of the Center for Nanoscience and Nanotechnology, casual conversations between scientists can lead to breakthroughs

A chemist and a physicist walk into a clean room. No, this is not the one about how many people it takes to change a light bulb. Nor is it the one about two Israelis and three opinions. This is a true story about how two doctoral students from different fields got talking and realized that they may be able to use chemistry to solve a nagging problem in physics. “These students were the best kind – curious and open to new ideas and different ways of approaching a problem,” says Prof. Gil Markovich of the Raymond and Beverly Sackler School of Chemistry. Prof. Yoram Dagan, Raymond and Beverly Sackler School of Physics and Astronomy, nods in agreement.

Markovich and Dagan were the students’ respective PhD advisors and quickly saw the benefit of collaborating. In their research, they sought a solution to prevent damage to the surface of semiconductors – small components that control electrical current in devices such as computers and mobile phones, which damage the functioning of the devices.

For this kind of research, a particularly sterile laboratory is required. The special conditions in the “clean room” include a constant temperature of 20 degrees, 50 percent humidity, and a very powerful filter that prevents the entry of dust particles into the laboratory space and is responsible for creating a sterile work environment. These conditions are essential for the production of certain materials, especially electronic chips, which can be disrupted by something as tiny as a grain of dust.

From cell phones to thermal cameras  

The scientists are using a chemical rather than physical process to create an electrical insulating thin film the thickness of a single atom. According to Dagan, “Unlike in physics, where non-organic materials are used, we used organic compounds to get the components that create the atom-thick layer.” In the process carried out by the scientists, they heated organic compounds to the point of dissolution. Once they touch the surface, they receive additional energy and break down until the process stops on its own. “This creates only a single layer of the insulating material, because there is not enough energy to form another layer,” Dagan explains. “In a cheap and rapid chemical process, we were able to offer an alternative to complicated and costly processes, and even to achieve a better result.”

Their invention could improve microelectronics in all the devices we carry in our pockets and have in our homes by making them faster, more efficient and more compact. “This is a long-term project – an idea that may be implementable twenty years down the line. Yet exploring this basic physics problem using nano-chemistry led us to an application that can be realized today,” says Dagan.

Markovich and Dagan have teamed up with industry experts for guidance in applying their technology to improve resolution in infrared cameras used for defense and security installations. The Israel Innovation Authority (formerly the Office of the Chief Scientist) has invested in the project with a grant reserved solely for projects that have a good chance to be commercialized in Israel. “It all begins, though, with basic science. Basic science is the foundation of knowledge. When we discover new possibilities and new materials, applications can grow,” stresses Dagan.

Collaboration opens new possibilities

Markovich and Dagan share a passion for unlocking the secrets of the universe: “We are both interested in origins,” says Dagan. “Gil researches the interaction of minerals with amino acids and DNA – the original building blocks of life.  I am interested in the fundamental properties of matter and materials. I would not think up chemical approaches to physical problems by myself. Our collaboration is opening up new possibilities.” says Dagan.

“This has been a fun ride,” adds Markovich. “First, Yoram is a nice person. And I never worked on these kinds of problems before. We have ideas for cooperation on chemical ways to create new materials for quantum computing. The future is wide open.” 

Featured iage:Prof. Gil Markovich and Prof. Yoram Dagan (Photo: Yoram Reshef)

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Chemistry,Honours & Awards

Congratulations to Prof. Doron Shabat of the School of Chemistry for receiving the 2018 ICS-Adama Prize for Technological Innovation

Prof. Doron Shabat of the School of Chemistry

The 2018 ICS-Adama Prize for Technological Innovation will be awarded to Prof. Doron Shabat for developing revolutionary chemiluminescent biological probes that are based on highly efficient synthetic luminophores.

The award ceremony will take place during the 84th ICS Annual Meeting on February 12, 2019.

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Chemistry,Engineering

A new discovery that could improve your laptop’s hard drive

Microscale superlubricity could pave way for improved electromechanical devices

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, such as computer hard drives. 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 and 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. 

Enormous implications for computers 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.

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Chemistry,Engineering

Modern laser science enhanced by 2,300-year-old tech

Archimedes’ screw inspires Tel Aviv University researchers to devise a novel particle-trapping laser beam

An active field of research, laser optical trapping works to control the movement and position of particles of different sizes and shapes. The ability to move small particles in a precise and controlled manner is important to both basic and applied science. For example, the ability to control the movement of single atoms can be used to realize quantum computing, and the research also contributes to the study of biological specimens and pollutants.

Now scientists at Tel Aviv University have harnessed a 2,300-year-old water displacement technology to develop a novel laser beam that traps and moves particles in specific directions.

“We have created a light beam that looks and acts like Archimedes’ screw,” says Dr. Alon Bahabad of the Physical Optics Laboratory at TAU’s School of Electrical Engineering. “Instead of traveling in a straight line like regular laser beams, our beam consists of two helical strands, akin to the shape of DNA, and we can use this beam to move very small particles. The rotation of the beam determines the direction in which the particles, whose size ranges between tens of nanometers to about 10 microns, are conveyed.”

 

Archimedes, renowned scientist from the 3rd century B.C.E

Archimedes, renowned scientist from the 3rd century B.C.E

The study, published in the journal Optica, was conducted by Dr. Bahabad’s students Barak HadadSahar Froim and Yaniv Eliezer in collaboration with Dr. Yael Roichman at TAU’s School of Chemistry and her students Harel Bagar and Tamir Admon.

From water to light

Archimedes, a Greek scientist who lived in the 3rd century B.C., is credited with inventing one of the first effective water pumps: a broad-threaded screw, bent around an axis encased by a cylinder or a tube.

“A major challenge in laser optical trapping is how to move particles toward a light source,” Dr. Bahabad says. “This is a problem because particles tend to move with the flow of light, or are pushed ‘downstream,’ so to speak. Our objective was to generate an upstream movement of trapped particles to create a ‘tractor beam.’ We’ve done just this by referring to an ancient idea.”

 

Just like beaming someone up a science fiction movie, the 'screw' draws in tiny particles

Just like beaming someone up a science fiction movie, the ‘screw’ draws in tiny particles 

Archimedes demonstrated that the rotation of a mechanical screw displaces water along the axis of the screw, against the pull of gravity. “We have devised an elegant tractor beam based on this simple idea,” Dr. Bahabad says. “The movement of trapped particles in our case depends on the rotation of the beam. If you rotate it one way, the particles are pushed downstream. Rotate it the other way, and they are pulled upstream.”

A standing wave

Dr. Bahabad and his team combined different light beams to create an interference pattern called a standing wave. Such interference patterns are characterized by alternating bright and dark areas. Particles within the beams were trapped by air movement near the particles due to heat deposited by the laser beam.

“When the particle is in a bright area of the beam, it gets hot and is pushed away by air molecules toward darker regions,” says Dr. Bahabad. “When we rotate the beam, the dark areas move and carry the trapped particles with them. This is how a vending machine that has a screw for moving snacks operates.

“We believe our discovery can find uses in biology, materials sciences, spectroscopy or any field that requires monitoring different materials or biological samples.”

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Chemistry,Honours & Awards

Top defense prize awarded to TAU professor

How has the science of materials affected our lives? Why do British people put milk in their tea? And what does that have to do with the clothes we’ll be wearing in the future?

The prestigious Ministry of Defense Prize is awarded annually to researchers and teams from the defense industry and R&D institutions that have made significant, groundbreaking contributions to Israeli defense R&D. It was first conceived by Israel’s first Prime Minister, David Ben-Gurion, as an award for contributions to the security of the State of Israel.

This year, the Prize was awarded to Prof. (Emer.) Emanuel Peled of TAU’s Raymond and Beverly Sackler School of Chemistry, the sole representative from academia among the winners this year.  

Prof. Peled is a leading world scientist in the field of batteries and fuel cells. He is the developer of the Solid Electrolyte Interphase model for active metal non-aqueous batteries, which are the key component of lithium batteries. Together with his students, Prof. Peled pioneered the development of calcium-thionyl chloride batteries for deep oil drilling. He was the first to develop a rechargeable lithium-sulfur battery based on porous carbon cathode loaded with sulfur.

Prof. Emanuel Peled

Improving the way we charge batteries

Prof. Peled has developed a 3-D silicon-chip lithium-ion micro-battery, together with TAU Prof. Dana Golodnitsky of the School of Chemistry and Prof. Menachem Nathan of the Iby and Aladar Fleischman Faculty of Engineering. He also cooperated with Rafael Industries on the development of lithium thermal batteries for missiles, which the company produces for the Israel Defense Forces and for export. Together with a team at  JPL- NASA he developed a composite solid electrolyte.

Prof. Peled was co-founder of the startup Chemtronics, a company that developed a unique state of health and state of charge meter for lithium batteries. The technology was transferred to an Israeli electronic company (QPS). He is a co-founder of EnStorage, a startup company aimed at the development and commercialization of very large energy storage systems based on a regenerative fuel cell and a co-founder of Honeycomb, a startup company aimed at the development of 3D batteries. 

Twenty years of continued curiosity

Prof. Peled joined the TAU faculty in 1973 as lecturer and became Full Professor in 1991. In 2011 Prof. Peled retired as Professor Emeritus however, he continues to teach and conduct research. His research group consists of six PhD students, two postdoc researchers and three engineers.

From 1997 to 2000 Prof. Peled was Director of TAU’s Wolfson Applied Material Research Center and the Gordon Center of Energy Studies. He led the committee that established the multi faculty graduate program in Science and Engineering of Materials and he serves as its coordinator.

For his achievements in the field of power sources Prof. Peled was awarded the Electrochemical Society Battery Division Research Award, the Landau research Award, the International Battery Associations (IBA) Award and the Israel Chemical Society Outstanding Scientist Award. He has published 177 papers and holds 47 patents and pending patents in the fields of batteries and fuel cells. 

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