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Graphene transistors enable selective ion sensing

Posted By Graphene Council, Friday, June 26, 2020
New research shows that graphene field effect transistors can be used to selectively detect ions in a liquid solution. The work, just published in Nature Communications, paves the way to applications such as genome sequencing, medical diagnostics, environmental monitoring, and industrial process control.

State of the art technology for detecting and resolving ions in solution relies on ion sensitive field effect transistors (ISFETs). Standard ISFETs are made of silicon, due to the ease of technological processing, however silicon ISFETs have some drawbacks that hinder their performance in real-life scenarios.

To achieve selectivity to different ionic species, ISFETs that are selective to specific ions are assembled into arrays and post-processing is used to estimate ion concentration. Since many ISFETs are packed on small areas to implement selectivity, each ISFET has to be made small, which leads to low-frequency noise that is prominent in silicon. Increasing the size of individual ISFETs leads to loss of resolution, which imposes a tradeoff that limits practical use.

The present research, reported by teams in Canada and Spain, overcomes the tradeoff by using graphene instead of silicon as the ISFET channel. Graphene has high carrier mobility even in large-area devices, which enables construction of a single large sensor for multiple ionic species. Post-processing of the transistor signal enables the measuring of concentration of K+, Na+, NH4+, NO3-, SO42-, and Cl- ions down to concentrations lower than 10-5 M in a multianalyte solution. These ions were chosen due to their prominence in agriculture runoff, hence the importance of their detection in water quality monitoring.

Practical graphene ISFET use was demonstrated by monitoring the uptake of ions by duckweed in an aquarium over a period of three weeks. The researchers tracked, with high precision and selectivity, the concentration of seven different ionic species over time after adding plant nutrients to the aquarium. This novel work demonstrates that large-area graphene ISFETs can be fabricated from wafer scale graphene by a facile method, yielding ISFETs with a high signal-to-noise-ratio and high-resolution sensing. Graphene ISFETs hence overcome poor selectivity typically associated with ISFETs made of other materials and can be applied to real-life scenarios in environmental sensing.

Tags:  Electronics  Graphene  Sensors  transistor 

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New study unveils ultrathin boron nitride films for next-generation electronics

Posted By Graphene Council, Friday, June 26, 2020
An international team of researchers, affiliated with UNIST has unveiled a novel material that could enable major leaps in the miniaturization of electronic devices. Published in the prestigious journal Nature, this study represent a significant achievement for future electronics.

This breakthrough comes from a research, conducted by Professor Hyeon Suk Shin (School of Natual Sciences, UNIST) and Principal Researcher Dr. Hyeon-Jin Shin from Samsung Advanced Institute of Technology (SAIT), in collaboration with Graphene Flagship researchers from University of Cambridge (UK) and Catalan Institute of Nanoscience and Nanotechnology (ICN2, Spain).

In this study, the team successfully demonstrated the synthesis of thin film of amorphous boron nitride (a-BN) with extremely low dielectric constant as well as high breakdown voltage and superior metal barrier properties. The research team noted that this newly fabricated material has great potential as interconnect insulators in the next-generation of electronic circuits.

In the ongoing process of miniaturization of logic and memory devices in electronic circuits, minimizing the dimensions of interconencts - metal wires that link the different device components on the chip - is crucial to guarantee improved performance and faster response of the device. Extensive research efforts have been devoted to decreasing the resistance of scaled interconnects because integration of dielectrics using complementary metal oxide semiconductor (CMOS) compatible processes has proven to be exceptionally challenging. According to the research team, the required interconnect isolation materials should not only possess low relative dielectric constants (referred to as k-values), but should also be thermally, chemically, and mechanically stable.

There has been an ongoing quest to obtain materials with ultra-low-k (relative permittivity around or below 2) avoiding the artificial addition of pores in the thin film in the semiconductor industry for at least the past 20 years. Several attempts had been made to develop materials with desired characteristics, yet those materials have failed to be successfully integrated in interconnects due to poor mechanical properties or poor chemical stability upon integration, causing reliability failures.

In this study, the joint research has succeeded in demonstrating a Back-End-ofthe-Line (BEOL) compatible approach to grow amorphous boron nitride (a-BN) with extremely low-k dielectrics. In particular, they synthesized approximately 3 nm thin a-BN on a Si substrate, using low temperature remote inductively coupled plasma-chemical vapour deposition (ICP-CVD). The resulting material showed an extremely low dielectric constant in the range of 1.78, which is 30% lower than the dielectric constant of currently available insulators.

In this study, the joint research has succeeded in demonstrating a Back-End-ofthe-Line (BEOL) compatible approach to grow amorphous boron nitride (a-BN) with extremely low-k dielectrics. In particular, they synthesized approximately 3 nm thin a-BN on a Si substrate, using low temperature remote inductively coupled plasma-chemical vapour deposition (ICP-CVD). The resulting material showed an extremely low dielectric constant in the range of 1.78, which is 30% lower than the dielectric constant of currently available insulators.

"We found that temperature was the most important parameter with ideal a-BN film deposition occurring at 400° C," says Seokmo Hong in the Doctoral program of Natural Sciences, the first author of the study. "This material with ultra-low-k also manifests a high breakdown voltage and likely superior metal barrier properties, making the film very attractive for practical electronic applications."

Angle-dependent near-edge X-ray absorption fine structure (NEXAFS) measured in partial electron-yield (PEY) mode at Pohang Light Source-II 4D beam line was also used to investigate the chemical and electronic structures of a-BN. Their findings indicated that the irregular, random atomic arrangement causes the dielectric constant value to drop.

The new material also manifests excellent mechanical properties of high strength. Moreover, when researchers tested the diffusion barrier properties of a-BN in very harsh conditions, they found it can prevent metal atom migration from the interconnects into the insulator. This result will help resolves a long-standing issue of interconnects in CMOS integrated circuit fabrication, enabling further miniaturaization of electronic devices.

"Development of electrically, mechanically and thermally robust low-k materials (k < 2) has long been technically challenging," says Dr. Hyeon-Jin Shin from Samsung Advanced Institute of Technology (SAIT). "Our research is also a great example that shows companies and academic institutions working together to create greater synergy."

"Our results demonstrate that the amorphous counterpart of two-dimensional hexagonal BN possesses the ideal low-k dielectric characteristics for high-performance electronics," says Professor Shin. "If they are commercialized, it will be a great help in overcoming the crisis looming over the semiconductor industry."

Tags:  boron nitride  Electronics  Graphene  hexagonal boron nitride  Hyeon Suk Shin  Hyeon-Jin Shin  Samsung Advanced Institute of Technology  UNIST 

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Engineers advance insights on black phosphorus as a material for future ultra-low power flexible electronics

Posted By Graphene Council, Thursday, June 18, 2020
Black phosphorus is a crystalline material that is attracting growing research interest from semiconductor device engineers, chemists and material scientists to create high-quality atomically thin films.

From the perspective of a 2D layered material, black phosphorus shows promise for applications in next-generation flexible electronics that could enable advances in semiconductors, medical imaging, night vision and optical communication networks.

As a prospective graphene and silicon substitute, it has outstanding properties like tunable bandgap, which graphene lacks. A bandgap, an energy band in which no electron states can exist, is essential for creating the on/off flow of electrons that are needed in digital logic and for the generation of photons for LEDs and lasers.

Unfortunately, black phosphorus is hard to make and hard to keep. It degrades quickly when exposed to air. Why this happens and the exact mechanisms by which it happens—whether oxygen or moisture in the air degrade or both—remain a topic of active debate in the research community.

Vanderbilt engineering researchers have shown for the first time that the reaction of black phosphorus to oxygen can be observed at the atomic scale using in situ-transmission electron microscopy (TEM).  See YouTube videos.

The results are reported in their paper—Visualizing Oxidation Mechanisms in Few-Layered Black Phosphorus via In Situ Transmission Electron Microscopy—in the American Chemical Society’s Applied Materials & Interfaces journal.

“In research, a lot of times different and often contradictory hypothesis exist in the scientific community. However, the ability to observe a reaction at atomic resolution in real-time offers much needed clarity to propel advances. We are using the insights from our in-situ TEM experiments at atomic resolution in our lab to develop novel synthesis and preservation methods for black phosphorus,” said Piran Kidambi, assistant professor of chemical and biomolecular engineering.

“Current approaches have looked at encapsulating it with an oxide or polymer layer without really understanding why or how the oxidation proceeds,” said Andrew E. Naclerio, second year graduate student in the Department of Chemical and Biomolecular Engineering and the paper’s first author.

“Most understanding of black phosphorus oxidation has been based on results from spectroscopic probes,” said Kidambi, Naclerio’s adviser. In collaboration with Dmitri Zakharov, staff scientist at Brookhaven National Laboratory in Upton, New York, the team used environmental transmission electron microscopy (ETEM), which provides real time in-situ observation of structural  information on a sample and reaction at atomic resolution.

“This is one of the few microscopes in the United States and the world with the capability to perform atomic resolution imaging while introducing gases and heating,” Kidambi said. The collaboration grew from a peer-reviewed user proposal and is funded by Department of Energy (DOE).

“Some insights we obtained were that the reaction proceeds via the formation of an amorphous layer that subsequently evaporates. Different crystallographic edges lead to varying degrees of etching and this agrees well will with theoretical calculations,” Kidambi said.

The collaboration for theoretical calculations with two of the paper’s authors, researchers  Jeevesh Kumar and Mayank Shrivastava at the Indian Institute of Science in Bangalore, was formed at a conference where Kidambi was invited to give a talk.

The team aim to synthesize atomically thin films of black phosphorus using chemical vapor deposition, and insights on oxidation can be used to develop effective passivation techniques.

The Kidambi Research Group in the School of Engineering’s Department of Chemical and Biomolecular Engineering is affiliated with the Vanderbilt Institute of Nanoscale Science and Engineering (VINSE), the Interdisciplinary Materials Science Program and the Vanderbilt University Data Science Institute.

Tags:  Andrew E. Naclerio  Electronics  Graphene  photonics  Piran Kidambi  Vanderbilt Institute of Nanoscale Science and Engi 

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Researchers Advance Graphene Electronics

Posted By Graphene Council, Wednesday, June 17, 2020
In recent years, atomically flat layered materials have gained significant attention due to their prospects for building high-speed and low-power electronics. Best known among those materials is graphene, a single sheet of carbon atoms. Among the unique qualities of this family of materials is that they can be stacked on top of each other like Lego pieces to create artificial electronic materials.

However, while these van der Waals (vdW) heterostructures are critical to many scientific studies and technological applications of layered materials, efficient methods for building diverse vdW heterostructures are still lacking.

A team of researchers has found a versatile method for the construction of high-quality vdW heterostructures. The work is a collaboration between the laboratory of Davood Shahrjerdi, a professor of Electrical and Computer Engineering at the NYU Tandon School of Engineering and a faculty member of NYU WIRELESS; a group led by Javad Shabani at  the Center for Quantum Phenomena, New York University; and Kenji Watanabe and Takashi Taniguchi of National Institute for Materials Science, Japan. Their study was published this week in Nature Communications. 

A crucial step for building vdW graphene heterostructures is the production of large monolayer graphene flakes on a substrate, a process called mechanical “exfoliation.” The operation then involves transferring the graphene flakes onto a target location for the assembly of the vdW heterostructure. An optimal substrate would therefore make it possible to efficiently and consistently exfoliate large flakes of monolayer graphene and subsequently release them on-demand for constructing a vdW heterostructure.

The research team applied a simple yet elegant solution to this challenge involving the use of a dual-function polymeric film with a thickness of below five nanometers (less than 1/10,000th the width of a human hair). This modification allows them to “tune” the film properties such that it promotes the exfoliation of monolayer graphene. Then, for the Lego-like assembly, they dissolve the polymeric film underneath the monolayer graphene using a drop of water, freeing graphene from the substrate.

“Our construction method is simple, high-yield, and generalizable to different layered materials,” explained Shahrjerdi. “It enabled us to optimize the exfoliation step independently of the layer transfer step and vice versa, resulting in two major outcomes: a consistent exfoliation method for producing large monolayer flakes and a high-yield layer transfer of exfoliated flakes. Also, by using graphene as a model material, we further established the remarkable material and electronic properties of the resulting heterostructures.”

Tags:  Davood Shahrjerdi  Electronics  Graphene  graphene heterostructures  New York University 

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Pitt Engineer Maintains a Laser Focus to Grow Nanocarbons on Flexible Devices

Posted By Graphene Council, Wednesday, June 17, 2020
Fabrication of flexible and wearable electronics often requires integrating various types of advanced carbon nanomaterials - such as graphene, nanotubes, and nanoporous carbon - because of their remarkable electrical, thermal, and chemical properties. However, the extreme environments needed to chemically synthesize these nanomaterials means they can only be fabricated on rigid surfaces that can withstand high temperatures. Printing already-made nanocarbons onto flexible polymeric materials is generally the only option, but limits the potential customization.

To overcome this limitation, researchers at the University of Pittsburgh Swanson School of Engineering are investigating a new scalable manufacturing method for creating customizable types of nanocarbons on-demand - directly where they are needed - on flexible materials.

The research is led by Mostafa Bedewy, assistant professor of industrial engineering at Pitt, who received a $244,748 EAGER award from the National Science Foundation in support of this effort. The project, “Transforming Flexible Device Manufacturing by Bottom-up Growth of Nanocarbons Directly on Polymers,” will enable patterning functional nanocarbons needed for a number of emerging flexible-device applications in healthcare, energy, and consumer electronics.

Bedewy’s group is already working on another NSF-funded project that utilizes a custom-designed reactor to grow “nanotube forests” through a process called chemical vapor deposition (CVD). This enables the synthesis of carbon nanotubes from catalyst nanoparticles by the decomposition of carbon-containing gases. The process, however, is not suitable for growing nanocarbons directly onto commercial polymers.

“When we grow nanocarbons by CVD on silicon, it requires temperatures exceeding 700 degrees Celsius, in the presence of hydrocarbon gases and hydrogen,” explained Bedewy, who leads the NanoProduct Lab in the Swanson School's Department of Industrial Engineering. “While silicon can tolerate those conditions, polymers can’t, so CVD is out of the question.”

Instead, Bedewy’s group will utilize a laser in a similar way that common laser engraving machines function. When manufacturing flexible devices, current methods of printing carbon on polymers are limited in scalability and patterning resolution. This new laser-based method addresses these limitations. 

Rather than printing graphene from graphene ink, nanotubes from nanotube ink, and so on, the polymer material itself will act as the carbon source in the new process, and different types of nanocarbons can then grow from the polymer, like grass in a lawn - but instead of using sunlight, through a controlled laser.

“This approach allows us to control the carbon atomic structure, nanoscale morphology, and properties precisely in a scalable way,” said Bedewy. “Our research provides a tremendous opportunity to rapidly customize the type of nanocarbon needed for different devices on the same substrate without the need for multiple inks and successive printing steps.”

Producing functional nanocarbons in this manner will also enable high-rate roll-to-roll processing, which can potentially make manufacturing flexible electronics as fast and as inexpensive as printing newspapers.

“The multi-billion dollar global market for flexible electronics is still in its infancy, and is expected to grow exponentially because of accelerating demand in many applications,” Bedewy said “Exploring potentially transformative carbon nanomanufacturing processes is critical for realizing cutting-edge technologies.”

Tags:  Chemical Vapour Deposition  Electronics  Graphene  Mostafa Bedewy  nanomaterials  polymer  University of Pittsburgh 

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Lightning in a (nano)bottle: new supercapacitor opens door to better wearable electronics

Posted By Graphene Council, Friday, June 12, 2020
Researchers from Skoltech, Aalto University and Massachusetts Institute of Technology have designed a high-performance, low-cost, environmentally friendly, and stretchable supercapacitor that can potentially be used in wearable electronics. The paper was published in the Journal of Energy Storage.

Supercapacitors, with their high power density, fast charge-discharge rates, long cycle life, and cost-effectiveness, are a promising power source for everything from mobile and wearable electronics to electric vehicles. However, combining high energy density, safety, and eco-friendliness in one supercapacitor suitable for small devices has been rather challenging.

"Usually, organic solvents are used to increase the energy density. These are hazardous, not environmentally friendly, and they reduce the power density compared to aqueous electrolytes with higher conductivity," says Professor Tanja Kallio from Aalto University, a co-author of the paper.

The researchers proposed a new design for a "green" and simple-to-fabricate supercapacitor. It consists of a solid-state material based on nitrogen-doped graphene flake electrodes distributed in the NaCl-containing hydrogel electrolyte. This structure is sandwiched between two single-walled carbon nanotube film current collectors, which provides stretchability. Hydrogel in the supercapacitor design enables compact packing and high energy density and allows them to use the environmentally friendly electrolyte.

The scientists managed to improve the volumetric capacitive performance, high energy density and power density for the prototype over analogous supercapacitors described in previous research. "We fabricated a prototype with unchanged performance under the 50% strain after a thousand stretching cycles. To ensure lower cost and better environmental performance, we used a NaCl-based electrolyte. Still the fabrication cost can be lowered down by implementation of 3D printing or other advanced fabrication techniques," concluded Skoltech professor Albert Nasibulin.

Tags:  Aalto University  Albert Nasibulin  Electronics  Graphene  Massachusetts Institute of Technology  Supercapacitor  Tanja Kallio 

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Applying 'magic angle' twistronics to manipulate the flow of light

Posted By Graphene Council, Friday, June 12, 2020
Monash researchers are part of an international collaboration applying 'twistronics' concepts (the science of layering and twisting 2D materials to control their electrical properties) to manipulate the flow of light in extreme ways.

The findings, published today in the journal Nature, hold the promise for leapfrog advances in a variety of light-driven technologies, including nano-imaging devices; high-speed, low-energy optical computers; and biosensors.

This is the first application of Moire physics and twistronics to the light-based technologies, photonics and polaritonics, opening unique opportunities for extreme photonic dispersion engineering and robust control of polaritons on 2D materials.

APPLYING TWISTRONICS TO PHOTONS

The team took inspiration from the recent discovery of superconductivity in a pair of stacked graphene layers that were rotated to the 'magic twist angle' of 1.1 degrees.

In this stacked, misaligned configuration, electrons flow with no resistance, while separately, each of the two graphene layers shows no special electrical properties.

The discovery has shown how the careful control of rotational symmetries can unveil unexpected material responses.

The research team was led by Andrea Alù at the Advanced Science Research Center at the Graduate Center, CUNY, Cheng-Wei Qiu at National University of Singapore and Qiaoliang Bao formerly at Monash University.

The team discovered that an analogous principle can be applied to manipulate light in highly unusual ways. At a specific rotation angle between two ultrathin layers of molybdenum-trioxide, the researchers were able to prevent optical diffraction and enable robust light propagation in a tightly focused beam at desired wavelengths.

Typically, light radiated from a small emitter placed over a flat surface expands away in circles very much like the waves excited by a stone that falls into a pond. In their experiments, the researchers stacked two thin sheets of molybdenum-trioxide and rotated one of the layers with respect to the other. When the materials were excited by a tiny optical emitter, they observed widely controllable light waves over the surface as the rotation angle was varied. In particular, they showed that at the photonic 'magical twist angle' the configured bilayer supports robust, diffraction-free light propagation in tightly focused channel beams over a wide range of wavelengths.

"While photons - the quanta of light - have very different physical properties than electrons, we have been intrigued by the emerging discovery of twistronics, and have been wondering if twisted two-dimensional materials may also provide unusual transport properties for light, to benefit photon-based technologies," said Andrea Alù.

"To unveil this phenomenon, we used thin layers of molybdenum trioxide. By stacking two of such layers on top of each other and controlling their relative rotation, we have observed dramatic control of the light guiding properties. At the photonic magic angle, light does not diffract, and it propagates very confined along straight lines. This is an ideal feature for nanoscience and photonic technologies."

"Our experiments were far beyond our expectations," said Dr Qingdong Ou, who led the experimental component of the study at Monash University. "By stacking 'with a twist' two thin slabs of a natural 2D material, we can manipulate infrared light propagation, most intriguingly, in a highly collimated style."

"Our study shows that twistronics for photons can open truly exciting opportunities for light-based technologies, and we are excited to continue exploring these opportunities," said National University of Singapore graduate student Guangwei Hu, who led the theoretical component.

"Following our previous discovery published in Nature in 2018, we found that biaxial van der Waals semiconductors like α-MoO3 and V2O5 represent an emerging family of material supporting exotic polaritonic behaviors," said A/Prof Qiaoliang Bao, "These natural-born hyperbolic materials offer an unprecedented platform for controlling the flow of energy at the nanoscale."

DEVELOPMENT OF TWISTRONICS AND MAGIC ANGLES IN GRAPHENE

Novel electronic properties in 'misaligned' graphene sheets was first predicted by National University of Singapore Professor (and FLEET Partner Investigator) Antonio Castro Neto in 2007, and the 'magic angle' of 1.1 degrees was theorised by FLEET PI (University of Texas in Austin) in 2011.

Superconductivity in twisted graphene was experimentally demonstrated by Pablo Jarillo-Herrero (MIT) in 2018.

THE STUDY

Topological polaritons and photonic magic angles in twisted α-MoO3 bi-layers was published in Nature today, 11 June 2020 (DOI 10.1038/s41586-020-2359-9 ).

As well as support from the Australian Research Council, support was also provided by the US Air Force Office of Scientific Research, >Vannevar Bush Fellowship, Office of Naval Research, and National Science Foundation, as well as Singapore's Agency for Science Technology and Research (A*STAR), and China's National Natural Science Foundation.

Layering and twisting of 2D materials was performed at Monash University (Department of Materials Science and Engineering), while the topological polaritons was observed and characterised at the Melbourne Centre for Nanofabrication (MCN), the Victorian Node of the Australian National Fabrication Facility (ANFF).

PHOTONICS AT FLEET

Experimental physicist Dr Qingdong Ou is a research fellow now working with Prof Michael Fuhrer at Monash University to study nano-device fabrication based on 2D materials, within FLEET's Enabling technology B.

Qingdong seeks to minimise energy losses in light-matter interactions, aiming to realise ultra-low energy consumption in 2D-material-based photonic and optoelectronic devices. He also studies highly-confined low-loss polaritons in 2D materials using near-field optical nano-imaging within FLEET's Research theme 2.

FLEET is an Australian Research Council Centre of Excellence developing a new generation of ultra-low energy electronics.

Tags:  2D materials  Andrea Alù  CUNY  Electronics  Graphene  Monash University  photonics  Qingdong Ou 

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UT Projects Win $23.6M in R&D Funds as Part of Portuguese Government Technology Program

Posted By Graphene Council, Wednesday, June 10, 2020
The UT Austin Portugal program, a 13-year-old innovation partnership between the university and the Portuguese government, received $23.6 million in funding to pursue 11 R&D projects as part of a major technology initiative from Portugal’s Ministry of Science, Technology and Higher Education.

The projects fall under four major categories: nanomaterials, earth-space interactions, medical physics and advanced computing. The teams will spend the next three years developing their projects, which could transform industries like automotive, space, health care and data science.

“Ranging from electromagnetic interference shielding nanomaterials, to in-beam time-of-flight positron emission tomography for proton radiation therapy, all the way to an ocean and climate change monitoring constellation based on radar altimeter data combined with gravity and ocean temperature and salinity measurements, the spread, number, and quality of the UT Austin Portugal joint strategic projects selected for funding within the recent competitive solicitation set forth by the Foundation for Science and Technology and National Innovation Agency are truly outstanding,” said Manuel Heitor, Portugal’s Minister of Science, Technology and Higher Education. “I look forward to witnessing the results of such collaborative research between Portuguese and UT researchers.”

The call for proposals included just three universities: The University of Texas at Austin, Carnegie Mellon University and the Massachusetts Institute of Technology. UT won the majority of the investment dollars, about 40% of the funding, and saw the most projects funded among the three engineering powerhouses.

“We had anticipated four to five projects would be selected for strategic grant awards and were astounded when we learned 11 had been selected by the evaluation panel in Portugal,” said John Ekerdt, Cockrell School associate dean for research and principal investigator for UT Austin Portugal. “This is a testament to the outstanding faculty and quality projects they proposed with collaborators in Portugal and to the close ties that have been forged between UT researchers and faculty and counterparts in Portugal.”

“The performance of the UT Austin Portugal program in the 2019 call for strategic projects has been remarkable,” said Marco Bravo, executive director of the UT Austin Portugal program. “Eleven of 14 project proposals submitted by the UT Austin Portugal research consortia were approved for funding through an independent assessment process. Overall, UT Austin Portugal saw 11 of its groundbreaking, industry-led proposals approved out of a total of 25 projects approved at this solicitation that included proposals from two other international partnerships, corresponding to nearly $24 million over three years. That’s 40% of total funding to UT Austin Portugal projects, the largest share of research dollars available. UT Austin researchers are to be congratulated on this effort.”

The UT Austin Portugal program dates back to 2007, and it is one of several partnerships between the Portuguese government and research institutions. The goal is to elevate science and technology in Portugal while fostering strong partnerships to help universities continue to innovate. The partnership with UT was extended in 2018, continuing the alliance until at least 2030.

“Of the three international partnerships with American universities sponsored by the Portuguese Foundation for Science and Technology in Portugal, the partnership with UT Austin had the best performance in this call, which was designed and launched on the Portuguese side,” said José Manuel Mendonça, national director of the program. “The 11 approved projects represent a proposal success rate of almost 80% for the UT Austin Portugal Program. The approved projects will, undoubtedly, contribute to promoting and strengthening collaborations with UT Austin in high-level R&D matters with immediate transposition to various sectors of economic activity, several of which are critical to Portugal's competitive position at an international level.”

About a third of the funds for UT’s projects come from the university, with the rest coming from a combination of public and private Portuguese entities. Each project team in Portugal is led by a Portuguese company. The UT side includes 21 faculty members and one from the MD Anderson Cancer Center.

Here is a look at the UT projects:

Shielding electronic devices from electromagnetic interference
This project proposes to use the “wonder material” graphene to improve on methods to combat electromagnetic interference, which can disrupt circuits and cause devices to fail. The team plans to create two composites with electromagnetic interference shielding capabilities and fabricate a solution to protect electric wires used in the automotive industry.

UT Austin Faculty: Deji Akinwande, Cockrell School of Engineering, Department of Electrical and Computer Engineering; Brian Korgel, Cockrell School of Engineering, McKetta Department of Chemical Engineering

New lasers for next-generation biomedical imaging
The use of multiphoton microscopy to examine cell behavior in live tissue over time has become an important research tool for learning more about brains and tumors. This project aims to increase the speed and depth of this form of imaging and diagnostics through the development and application of ultrashort laser pulses.

UT Austin Faculty: Andrew Dunn, Cockrell School of Engineering, Department of Biomedical Engineering; Adela Ben-Yakar, Cockrell School of Engineering, Walker Department of Mechanical Engineering

Nano-satellites for gravitational field assessment
Researchers propose to develop a nano-satellite prototype for studying gravitational fields. The project will also develop a platform for future nano-satellite capabilities, including Earth observation, communications and exploration missions.

UT Austin Faculty: Byron Tapley, Cockrell School of Engineering, Department of Aerospace Engineering and Engineering Mechanics, and the Center for Space Research; Brandon Jones, Cockrell School of Engineering, Department of Aerospace Engineering and Engineering Mechanics, and the Texas Spacecraft Laboratory

Software to match big data with high-performance computing
The advancement of technology has generated huge troves of data, which requires stronger computing power to process and analyze all that information. This project aims to create a software bundle to help companies pair their big data operations with high-performance computing, which includes tools for managing challenges such as computing and research storage.

UT Austin Faculty: Vijay Chidambaram, College of Nature Sciences, Department of Computer Science; Todd Evans, Texas Advanced Computing Center

Sensors for monitoring cancer patients
This project will develop a biosensor that can be injected into prostate cancer patients after surgery. The minimally invasive sensor would allow medical personnel to monitor high-risk patients remotely and look for the development of early tumors, with the potential to increase the predictive value of cancer screenings.

UT Austin Faculty: Thomas Milner, Cockrell School of Engineering, Department of Biomedical Engineering; James Tunnell, Cockrell School of Engineering, Department of Biomedical Engineering

Wearable rehabilitation devices
Researchers will develop a series of nano-sensors embedded into clothing that administer electrostimulation to people suffering from a lack of mobility and motor deficiency. The sensors could be monitored remotely by health professionals, creating a mobile rehabilitation option for people who have trouble getting to a doctor’s office consistently or want greater freedom to complete treatment anywhere. The team envisions its project as a tool mostly for elderly people, but it has applications for training high-level athletes as well.

UT Austin Faculty: George Biros, Cockrell School of Engineering, Walker Department of Mechanical Engineering, and the Oden Institute for Computational Engineering and Sciences; Michael Cullinan, Cockrell School of Engineering, Walker Department of Mechanical Engineering

Software for gathering better data on manufacturing
Getting reliable data on manufacturing processes proves challenging due to issues with placing sensors in the right spots and retaining strong connectivity. Thin films loaded with small sensors that can be applied directly to the equipment represent a promising solution; however, installation has proved difficult. This project proposes a new set of software to make it easier to layer these films on top of equipment by providing necessary data to avoid mechanical problems during installation.

UT Austin Faculty: Rui Huang, Cockrell School of Engineering, Department of Aerospace Engineering and Engineering Mechanics, Center for Mechanics of Solids, Structures and Materials; Kenneth M. Liechti, Cockrell School of Engineering, Department of Aerospace Engineering and Engineering Mechanics, Center for Mechanics of Solids, Structures and Materials

A new way to measure next-generation cancer therapy
Proton radiation therapy, the use of protons rather than X-rays to treat cancer patients, is on the rise, but measuring the distance protons travel proves problematic. Typically, it takes a ring of detectors surrounding the patient to get accurate measurements, but that poses geometric challenges. This project proposes to develop a new type of Positron Emission Tomography scan, which shows how tissues and organs are functioning to better understand the range of protons and whether they are traveling to the right spots to attack the cancer.

UT Faculty: Karol Lang, College of Natural Sciences, Department of Physics; Narayan Sahoo, University of Texas MD Anderson Cancer Center, Department of Radiation Physics

Satellite constellations for monitoring climate change
This project aims to develop the next generation of radar altimeter instruments — which measure the distance between an aircraft and the terrain below it — and a series of small satellites that can understand long-term variability in local, regional and global climate created by changes in sea levels due to water temperature. The project also includes a data processing and visualization system using advanced modeling, estimation techniques, statistical and scientific machine learning methods and error analysis.

UT Austin Faculty: Byron Tapley, Cockrell School of Engineering, Department of Aerospace Engineering and Engineering Mechanics Department, and the Center for Space Research; Patrick Heimbach, Jackson School of Geosciences, Department of Geological Sciences, and the Oden Institute for Computational Engineering and Sciences

Improving cutting tools for airline and automotive components
Fabricating parts of cars and planes is hard on cutting tools and tends to ware them down. This project aims to develop coatings that better protect and extend the lifespan of these crucial pieces of equipment. The team also plans to develop simulation programs to improve cutting tools’ performance.

UT Austin Faculty: Gregory J. Rodin, Cockrell School of Engineering, Department of Aerospace Engineering and Engineering Mechanics, and the Oden Institute for Computational Engineering and Sciences; Filippo Mangolini, Cockrell School of Engineering, Walker Department of Mechanical Engineering

An alternative to traditional water treatment options
Traditional water treatment tech struggles to efficiently remove high amounts of pollutants from some types of surface and groundwater. This team is looking to use metallic nanoparticles to clean water by improving a process called catalytic hydrogenation, which involves adding hydrogen via a metallic catalyst.

UT Austin Faculty: Charles J. Werth, Cockrell School of Engineering, Department of Civil, Architectural, and Environmental Engineering; Simon M. Humphrey, College of Natural Sciences, Department of Chemistry

Tags:  Biomedical  Carnegie Mellon University  Electronics  Environment  Graphene  Healthcare  John Ekerdt  Marco Bravo  Massachusetts Institute of Technology  nanomaterials  Sensors  The University of Texas at Austin  Water Purification 

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Graphene and 2D materials could move electronics beyond ‘Moore’s Law’

Posted By Graphene Council, Thursday, June 4, 2020
A team of researchers based in Manchester, the Netherlands, Singapore, Spain, Switzerland and the USA has published a new review on a field of computer device development known as spintronics, which could use graphene as a building block for next-generation electronics.

Recent theoretical and experimental advances and phenomena in studies of electronic spin transport in graphene and related two-dimensional (2D) materials have emerged as a fascinating area of research and development.

Spintronics is the combination of electronics and magnetism at nanoscale and could allow electronic development at speeds exceeding Moore’s law, which observes that computer processing power roughly doubles every two years, while the price halves. Spintronic devices may offer higher energy efficiency and lower dissipation as compared to conventional electronics, which rely on charge currents. In principle, we could have phones and tablets operating with spin-based transistors and memories, greatly improving speed and storage capacity.

Since its isolation in 2004, graphene has opened the door for other 2D materials. Researchers can then use these materials to create stacks of 2D materials called heterostructures. These can be combined with graphene to create new ‘designer materials’ to produce applications originally limited to science fiction.

As published in APS Journal Review of Modern Physics, the review focuses on the new perspectives provided by heterostructures and their emergent phenomena, including proximity-enabled spin-orbit effects, coupling spin to light, electrical tunability and 2D magnetism.

The average person already encounters spintronics in laptops and PCs, which are already using spintronics in the form of the magnetic sensors in the reading heads of hard disk drives. These sensors are also used in the automotive industry.

Dr Ivan Vera Marun, Lecturer in Condensed Matter Physics at The University of Manchester said: “The continuous progress in graphene spintronics, and more broadly in 2D heterostructures, has resulted in the efficient creation, transport and detection of spin information using effects previously inaccessible to graphene alone.

“As efforts on both the fundamental and technological aspects continue, we believe that ballistic spin transport will be realised in 2D heterostructures, even at room temperature. Such transport would enable practical use of the quantum mechanical properties of electron wave functions, bringing spins in 2D materials to the service of future quantum computation approaches.”

Controlled spin transport in graphene and other two-dimensional materials has become increasingly promising for applications in devices. Of particular interest are custom-tailored heterostructures, known as van der Waals heterostructures, that consist of stacks of two-dimensional materials in a precisely controlled order.

Billions of spintronic devices such as sensors and memories are already being produced. Every hard disk drive has a magnetic sensor that uses a flow of spins, and magnetic random access memory (MRAM) chips are becoming increasingly popular.

Professor Francisco Guinea, who co-authored the paper, said: “The field of spintronics has brought to light a number of novel aspects in the behaviour of solids. The study of fundamental aspects of the motion of spin carrying electrons is one of the most active fields in the physics of condensed matter.

“The identification and characterisation of new quantum materials with non-trivial topological electronic and magnetic properties is being intensively studied worldwide, after the formulation, in 2004, of the concept of topological insulators. Spintronics lies at the core of this search. Because of their purity, strength and simplicity, 2D materials are the best platform to find these unique topological features that relate quantum physics, electronics and magnetism.”

Overall, the field of spintronics in graphene and related 2D materials is currently moving towards the demonstration of practical graphene spintronic devices such as coupled nano-oscillators for applications in fields of space communication, high‐speed radio links, vehicle radar and interchip communication applications.

Tags:  2D materials  electronics  Francisco Guinea  Graphene  Ivan Vera Marun  The University of Manchester 

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New method predicts spin dynamics of materials for quantum computing

Posted By Graphene Council, Thursday, June 4, 2020
Researchers at UC Santa Cruz have developed a theoretical foundation and new computational tools for predicting a material's spin dynamics, a key property for building solid-state quantum computing platforms and other applications of spintronics.

Spin is a fundamental property of electrons and other particles, and the rapidly growing field of spintronics uses spin states in a manner analogous to the use of electrical charge in electronics. Spin can be used as the basis for qubits (quantum bits) and single-photon emitters in applications of quantum information science, including quantum computation, communication, and sensing.

Qubits can be made from any quantum system that has two states, but the challenge is to maintain quantum coherence (a relationship between quantum states) long enough to allow manipulation of the qubits. Decoherence means a loss of information from the system, and spin qubits can lose coherence by interacting with their environment through, for example, lattice vibrations within the material.

"The key property for quantum information science is the lifetime of the spin states, known as the spin relaxation and decoherence time," said Yuan Ping, assistant professor of chemistry at UC Santa Cruz. "For quantum information applications, we need materials with long spin relaxation times."

In a paper published June 3 in Nature Communications, Ping and her coauthors at UCSC and Rensselaer Polytechnic Institute present a new theoretical framework and computational tools for accurately predicting the spin relaxation time of any material, which was not previously possible.

"These days, people just make a material and try it to see whether it works. Now we have the predictive capability from quantum mechanics that will allow us to design materials with the properties we want for applications in quantum information science," she said. "And if you have a promising material, this can tell you how to change it to make it better."

The researchers established methods for determining spin dynamics from first principles, meaning that no empirical parameters from experimental measurements are needed to do the calculations. They also showed that their approach is generalizable to different types of materials with vastly different crystal symmetries and electronic structures.

For example, they predicted accurately the spin relaxation time of centrosymmetric materials such as silicon, ferromagnetic iron, and graphene, as well as non-centrosymmetric materials such as molybdenum disulfide and gallium nitride, highlighting the predictive power of their method for a broad range of quantum materials.

By enabling the rational design of materials, instead of searching blindly and testing a wide range of materials experimentally, these new methods could enable rapid advances in the field of quantum information technologies.

Tags:  Electronics  Graphene  quantum materials  Rensselaer Polytechnic Institute  UC Santa Cruz  Yuan Ping 

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