Tag Archives: Monash University

Metacrime: the line between the virtual and reality

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An August 15, 2024 Griffith University (Australia) press release (also on EurekAlert) presents research on a relatively new type of crime, Note: A link has been removed,

If you thought your kids were away from harm playing multi-player games through VR headsets while in their own bedrooms, you may want to sit down to read this.

Griffith University’s Dr Ausma Bernot teamed up with researchers from Monash University, Charles Sturt University and University of Technology Sydney to investigate what has been termed as ‘metacrime’ – attacks, crimes or inappropriate activities that occur within virtual reality environments.

The ‘metaverse’ refers to the virtual world, where users of VR headsets can choose an avatar to represent themselves as they interact with other users’ avatars or move through other 3D digital spaces.

While the metaverse can be used for anything from meetings (where it will feel as though you are in the same room as avatars of other people instead of just seeing them on a screen) to wandering through national parks around the world without leaving your living room, gaming is by far its most popular use.   

Dr Bernot said the technology had evolved incredibly quickly.

“Using this technology is super fun and it’s really immersive,” she said.

“You can really lose yourself in those environments.

“Unfortunately, while those new environments are very exciting, they also have the potential to enable new crimes.

“While the headsets that enable us to have these experiences aren’t a commonly owned item yet, they’re growing in popularity and we’ve seen reports of sexual harassment or assault against both adults and kids.”

In a December 2023 report, the Australian eSafety Commissioner estimated around 680,000 adults in Australia are engaged in the metaverse.

This followed a survey conducted in November and December 2022 by researchers from the UK’s Center for Countering Digital Hate, who conducted 11 hours and 30 minutes of recorded user interactions on Meta’s Oculus headset in the popular VRChat.

The researchers found most users had been faced with at least one negative experience in the virtual environment, including being called offensive names, receiving repeated unwanted messages or contact, being provoked to respond to something or to start an argument, being challenged about cultural identity or being sent unwanted inappropriate content.

Eleven per cent had been exposed to a sexually graphic virtual space and nine per cent had been touched (virtually) in a way they didn’t like.

Of these respondents, 49 per cent said the experience had a moderate to extreme impact on their mental or emotional wellbeing.

With the two largest user groups being minors and men, Dr Bernot said it was important for parents to monitor their children’s activity or consider limiting their access to multi-player games.

“Minors are more vulnerable to grooming and other abuse,” she said.

“They may not know how to deal with these situations, and while there are some features like a ‘safety bubble’ within some games, or of course the simple ability to just take the headset off, once immersed in these environments it does feel very real.

“It’s somewhere in between a physical attack and for example, a social media harassment message – you’ll still feel that distress and it can take a significant toll on a user’s wellbeing.

“It is a real and palpable risk.”

Monash University’s You Zhou said there had already been many reports of virtual rape, including one in the United Kingdom where police have launched a case for a 16-year-old girl whose avatar was attacked, causing psychological and emotional trauma similar to an attack in the physical world.

“Before the emergence of the metaverse we could not have imagined how rape could be virtual,” Mr Zhou said.

“When immersed in this world of virtual reality, and particularly when using higher quality VR headsets, users will not necessarily stop to consider whether the experience is reality or virtuality.

“While there may not be physical contact, victims – mostly young girls – strongly claim the feeling of victimisation was real.

“Without physical signs on a body, and unless the interaction was recorded, it can be almost impossible to show evidence of these experiences.”

With use of the metaverse expected to grow exponentially in coming years, the research team’s findings highlight a need for metaverse companies to instil clear regulatory frameworks for their virtual environments to make them safe for everyone to inhabit.

Here’s a link to and a citation for the paper,

Metacrime and Cybercrime: Exploring the Convergence and Divergence in Digital Criminality by You Zhou, Milind Tiwari, Ausma Bernot & Kai Lin. Asian Journal of Criminology 19, 419–439 (2024) DOI: https://doi.org/10.1007/s11417-024-09436-y Published online: 09 August 2024 Issue Date: September 2024

This paper is open access.

Shortlist for 2024 Maddox Prize for Standing up for Science

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Sense about Science is a UK “independent charity that promotes the public interest in sound science and evidence,” according to the organization’s homepage. An October 29, 2024 Sense About Science announcement arrived in my email box (also online here),

Unfortunately, we don’t yet live in a world where it is safe for researchers to always speak out openly and honestly about research findings, even when it is important for society that they do so. We need to be able to ask difficult and sometimes uncomfortable scientific questions if we are to make decisions that affect the lives of many on the best available evidence. 

Fortunately, however, there are brave researchers around the world who bringing evidence to public debate despite the potential of facing harassment or intimidation. The Maddox Prize is awarded by Springer Nature and Sense about Science to individuals who have shown courage and integrity in standing up for sound science and evidence and encourages others to do the same.  

This year the judges have shortlisted 8 inspiring individuals from all the nominations received. They are:  

Patrick Ball for his rigorous statistical work identifying, cataloguing and prosecuting war crimes. Patrick founded the Human Rights Data Analyst Group (HRDAG) and has spent over thirty years producing analysis for truth commissions, non-governmental organisations, international criminal tribunals and United Nations missions.  

Kelly Cobey for her work implementing open science and championing the need to reform research assessment. Kelly is an Associate Professor at the University of Ottawa, where she is also director of the Metaresearch and Open Science programme. 

Sholto David for his active role in identifying fabricated studies and results and protecting the integrity of science. Sholto is an analytical scientist with a PhD in cell and molecular biology from Newcastle University.  

Ann McNeill for her work on studying interventions to reduce threats posed by cigarette smoking. Ann is a Professor of Tobacco Addiction in the National Addiction Centre at the Institute of Psychiatry, Psychology and Neuroscience, King’s College London.  

Ben Mol for his work exposing scientific fraud in obstetrics and gynaecology research and removing fabricated papers from the literature. Ben is a Professor of obstetrics/gynaecology at Monash University in Australia.  

John Nkengasong for conducting epidemiological studies of the COVID-19 virus in Africa whilst he was the director of the Africa Centres for Disease Control and Prevention. His efforts played a huge part in protecting the African population from COVID-19 despite challenges such as testing in regions of conflict. John is a virologist currently serving as the Global AIDS Coordinator in the Biden administration.  

Shiba Subedi for his dedication campaigning in Nepali society for better awareness and preparedness for earthquakes. Shiba currently works as a seismologist at the Nepal Academy of Science and Technology.  

Carola Vinuesa for her work using genetic sequencing to prevent unwarranted accusation of parents that they have harmed their children. Carola is internationally renowned for her discoveries in genetic causes of autoimmunity, and currently works at the Francis Crick Institute in London. 

Maddox Prize 2024 website

The winners will be announced on 6 November [2024] at a reception in London.

Good luck to all the nominees!

Revolutionizing electronics with liquid metal technology?

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I’m not sure I’d call it the next big advance in electronics, there are too many advances jockeying for that position but this work from Australia and the US is fascinating. From a Feb. 17, 2017 news item on ScienceDaily,

A new technique using liquid metals to create integrated circuits that are just atoms thick could lead to the next big advance for electronics.

The process opens the way for the production of large wafers around 1.5 nanometres in depth (a sheet of paper, by comparison, is 100,000nm thick).

Other techniques have proven unreliable in terms of quality, difficult to scale up and function only at very high temperatures — 550 degrees or more.

A Feb. 17, 2017 RMIT University press release (also on EurekAlert), which originated the news item, expands on the theme (Note: A link has been removed),

Distinguished Professor Kourosh Kalantar-zadeh, from RMIT’s School of Engineering, led the project, which also included colleagues from RMIT and researchers from CSIRO, Monash University, North Carolina State University and the University of California.

He said the electronics industry had hit a barrier.

“The fundamental technology of car engines has not progressed since 1920 and now the same is happening to electronics. Mobile phones and computers are no more powerful than five years ago.

“That is why this new 2D printing technique is so important – creating many layers of incredibly thin electronic chips on the same surface dramatically increases processing power and reduces costs.

“It will allow for the next revolution in electronics.”

Benjamin Carey, a researcher with RMIT and the CSIRO, said creating electronic wafers just atoms thick could overcome the limitations of current chip production.

It could also produce materials that were extremely bendable, paving the way for flexible electronics.

“However, none of the current technologies are able to create homogenous surfaces of atomically thin semiconductors on large surface areas that are useful for the industrial scale fabrication of chips.

“Our solution is to use the metals gallium and indium, which have a low melting point.

“These metals produce an atomically thin layer of oxide on their surface that naturally protects them. It is this thin oxide which we use in our fabrication method.

“By rolling the liquid metal, the oxide layer can be transferred on to an electronic wafer, which is then sulphurised. The surface of the wafer can be pre-treated to form individual transistors.

“We have used this novel method to create transistors and photo-detectors of very high gain and very high fabrication reliability in large scale.”

Here’s a link to and a citation for the paper,

Wafer-scale two-dimensional semiconductors from printed oxide skin of liquid metals by Benjamin J. Carey, Jian Zhen Ou, Rhiannon M. Clark, Kyle J. Berean, Ali Zavabeti, Anthony S. R. Chesman, Salvy P. Russo, Desmond W. M. Lau, Zai-Quan Xu, Qiaoliang Bao, Omid Kevehei, Brant C. Gibson, Michael D. Dickey, Richard B. Kaner, Torben Daeneke, & Kourosh Kalantar-Zadeh. Nature Communications 8, Article number: 14482 (2017) doi:10.1038/ncomms14482
Published online: 17 February 2017

This paper is open access.

Exceeding the sensitivity of skin with a graphene elastomer

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A Jan. 14, 2016 news item on Nanowerk announces the latest in ‘sensitive’ skin,

A new sponge-like material, discovered by Monash [Monash University in Australia] researchers, could have diverse and valuable real-life applications. The new elastomer could be used to create soft, tactile robots to help care for elderly people, perform remote surgical procedures or build highly sensitive prosthetic hands.

Graphene-based cellular elastomer, or G-elastomer, is highly sensitive to pressure and vibrations. Unlike other viscoelastic substances such as polyurethane foam or rubber, G-elastomer bounces back extremely quickly under pressure, despite its exceptionally soft nature. This unique, dynamic response has never been found in existing soft materials, and has excited and intrigued researchers Professor Dan Li and Dr Ling Qiu from the Monash Centre for Atomically Thin Materials (MCATM).

A Jan. 14, 2016 Monash University media release, which originated the news item, offers some insights from the researchers,

According to Dr Qiu, “This graphene elastomer is a flexible, ultra-light material which can detect pressures and vibrations across a broad bandwidth of frequencies. It far exceeds the response range of our skin, and it also has a very fast response time, much faster than conventional polymer elastomer.

“Although we often take it for granted, the pressure sensors in our skin allow us to do things like hold a cup without dropping it, crushing it, or spilling the contents. The sensitivity and response time of G-elastomer could allow a prosthetic hand or a robot to be even more dexterous than a human, while the flexibility could allow us to create next generation flexible electronic devices,” he said.

Professor Li, a director of MCATM, said, ‘Although we are still in the early stages of discovering graphene’s potential, this research is an excellent breakthrough. What we do know is that graphene could have a huge impact on Australia’s economy, both from a resources and innovation perspective, and we’re aiming to be at the forefront of that research and development.’

Dr Qiu’s research has been published in the latest edition of the prestigious journal Advanced Materials and is protected by a suite of patents.

Are they trying to protect the work from competition or wholesale theft of their work?

After all, the idea behind patents and copyrights was to encourage innovation and competition by ensuring that inventors and creators would benefit from their work. An example that comes to mind is the Xerox company which for many years had a monopoly on photocopy machines by virtue of their patent. Once the patent ran out (patents and copyrights were originally intended to be in place for finite time periods) and Xerox had made much, much money, competitors were free to create and market their own photocopy machines, which they did quite promptly. Since those days, companies have worked to extend patent and copyright time periods in efforts to stifle competition.

Getting back to Monash, I do hope the researchers are able to benefit from their work and wish them well. I also hope that they enjoy plenty of healthy competition spurring them onto greater innovation.

Here’s a link to and a citation for their paper,

Ultrafast Dynamic Piezoresistive Response of Graphene-Based Cellular Elastomers by Ling Qiu, M. Bulut Coskun, Yue Tang, Jefferson Z. Liu, Tuncay Alan, Jie Ding, Van-Tan Truong, and Dan Li. Advanced Materials Volume 28, Issue 1 January 6, 2016Pages 194–200 DOI: 10.1002/adma.201503957 First published: 2 November 2015

This paper appears to be open access.

SINGLE (3D Structure Identification of Nanoparticles by Graphene Liquid Cell Electron Microscopy) and the 3D structures of two individual platinum nanoparticles in solution

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It seems to me there’s been an explosion of new imaging techniques lately. This one from the Lawrence Berkelely National Laboratory is all about imaging colloidal nanoparticles (nanoparticles in solution), from a July 20, 2015 news item on Azonano,

Just as proteins are one of the basic building blocks of biology, nanoparticles can serve as the basic building blocks for next generation materials. In keeping with this parallel between biology and nanotechnology, a proven technique for determining the three dimensional structures of individual proteins has been adapted to determine the 3D structures of individual nanoparticles in solution.

A multi-institutional team of researchers led by the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab), has developed a new technique called “SINGLE” that provides the first atomic-scale images of colloidal nanoparticles. SINGLE, which stands for 3D Structure Identification of Nanoparticles by Graphene Liquid Cell Electron Microscopy, has been used to separately reconstruct the 3D structures of two individual platinum nanoparticles in solution.

A July 16, 2015 Berkeley Lab news release, which originated the news item, reveals more details about the reason for the research and the research itself,

“Understanding structural details of colloidal nanoparticles is required to bridge our knowledge about their synthesis, growth mechanisms, and physical properties to facilitate their application to renewable energy, catalysis and a great many other fields,” says Berkeley Lab director and renowned nanoscience authority Paul Alivisatos, who led this research. “Whereas most structural studies of colloidal nanoparticles are performed in a vacuum after crystal growth is complete, our SINGLE method allows us to determine their 3D structure in a solution, an important step to improving the design of nanoparticles for catalysis and energy research applications.”

Alivisatos, who also holds the Samsung Distinguished Chair in Nanoscience and Nanotechnology at the University of California Berkeley, and directs the Kavli Energy NanoScience Institute at Berkeley (Kavli ENSI), is the corresponding author of a paper detailing this research in the journal Science. The paper is titled “3D Structure of Individual Nanocrystals in Solution by Electron Microscopy.” The lead co-authors are Jungwon Park of Harvard University, Hans Elmlund of Australia’s Monash University, and Peter Ercius of Berkeley Lab. Other co-authors are Jong Min Yuk, David Limmer, Qian Chen, Kwanpyo Kim, Sang Hoon Han, David Weitz and Alex Zettl.

Colloidal nanoparticles are clusters of hundreds to thousands of atoms suspended in a solution whose collective chemical and physical properties are determined by the size and shape of the individual nanoparticles. Imaging techniques that are routinely used to analyze the 3D structure of individual crystals in a material can’t be applied to suspended nanomaterials because individual particles in a solution are not static. The functionality of proteins are also determined by their size and shape, and scientists who wanted to image 3D protein structures faced a similar problem. The protein imaging problem was solved by a technique called “single-particle cryo-electron microscopy,” in which tens of thousands of 2D transmission electron microscope (TEM) images of identical copies of an individual protein or protein complex frozen in random orientations are recorded then computationally combined into high-resolution 3D reconstructions. Alivisatos and his colleagues utilized this concept to create their SINGLE technique.

“In materials science, we cannot assume the nanoparticles in a solution are all identical so we needed to develop a hybrid approach for reconstructing the 3D structures of individual nanoparticles,” says co-lead author of the Science paper Peter Ercius, a staff scientist with the National Center for Electron Microscopy (NCEM) at the Molecular Foundry, a DOE Office of Science User Facility.

“SINGLE represents a combination of three technological advancements from TEM imaging in biological and materials science,” Ercius says. “These three advancements are the development of a graphene liquid cell that allows TEM imaging of nanoparticles rotating freely in solution, direct electron detectors that can produce movies with millisecond frame-to-frame time resolution of the rotating nanocrystals, and a theory for ab initio single particle 3D reconstruction.”

The graphene liquid cell (GLC) that helped make this study possible was also developed at Berkeley Lab under the leadership of Alivisatos and co-author Zettl, a physicist who also holds joint appointments with Berkeley Lab, UC Berkeley and Kavli ENSI. TEM imaging uses a beam of electrons rather than light for illumination and magnification but can only be used in a high vacuum because molecules in the air disrupt the electron beam. Since liquids evaporate in high vacuum, samples in solutions must be hermetically sealed in special solid containers – called cells – with a very thin viewing window before being imaged with TEM. In the past, liquid cells featured silicon-based viewing windows whose thickness limited resolution and perturbed the natural state of the sample materials. The GLC developed at Berkeley lab features a viewing window made from a graphene sheet that is only a single atom thick.

“The GLC provides us with an ultra-thin covering of our nanoparticles while maintaining liquid conditions in the TEM vacuum,” Ercius says. “Since the graphene surface of the GLC is inert, it does not adsorb or otherwise perturb the natural state of our nanoparticles.”

Working at NCEM’s TEAM I, the world’s most powerful electron microscope, Ercius, Alivisatos and their colleagues were able to image in situ the translational and rotational motions of individual nanoparticles of platinum that were less than two nanometers in diameter. Platinum nanoparticles were chosen because of their high electron scattering strength and because their detailed atomic structure is important for catalysis.

“Our earlier GLC studies of platinum nanocrystals showed that they grow by aggregation, resulting in complex structures that are not possible to determine by any previously developed method,” Ercius says. “Since SINGLE derives its 3D structures from images of individual nanoparticles rotating freely in solution, it enables the analysis of heterogeneous populations of potentially unordered nanoparticles that are synthesized in solution, thereby providing a means to understand the structure and stability of defects at the nanoscale.”

The next step for SINGLE is to recover a full 3D atomic resolution density map of colloidal nanoparticles using a more advanced camera installed on TEAM I that can provide 400 frames-per-second and better image quality.

“We plan to image defects in nanoparticles made from different materials, core shell particles, and also alloys made of two different atomic species,” Ercius says. [emphasis mine]

“Two different atomic species?”, they really are pushing that biology analogy.

Here’s a link to and a citation for the paper,

3D structure of individual nanocrystals in solution by electron microscopy by Jungwon Park, Hans Elmlund, Peter Ercius, Jong Min Yuk, David T. Limme, Qian Chen, Kwanpyo Kim, Sang Hoon Han, David A. Weitz, A. Zettl, A. Paul Alivisatos. Science 17 July 2015: Vol. 349 no. 6245 pp. 290-295 DOI: 10.1126/science.aab1343

This paper is behind a paywall.

Crowd computing for improved nanotechnology-enabled water filtration

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This research is the product of a China/Israel/Switzerland collaboration on water filtration with involvement from the UK and Australia. Here’s some general information about the importance of water and about the collaboration in a July 5, 2015 news item on Nanowerk (Note: A link has been removed),

Nearly 800 million people worldwide don’t have access to safe drinking water, and some 2.5 billion people live in precariously unsanitary conditions, according to the Centers for Disease Control and Prevention. Together, unsafe drinking water and the inadequate supply of water for hygiene purposes contribute to almost 90% of all deaths from diarrheal diseases — and effective water sanitation interventions are still challenging scientists and engineers.

A new study published in Nature Nanotechnology (“Water transport inside carbon nanotubes mediated by phonon-induced oscillating friction”) proposes a novel nanotechnology-based strategy to improve water filtration. The research project involves the minute vibrations of carbon nanotubes called “phonons,” which greatly enhance the diffusion of water through sanitation filters. The project was the joint effort of a Tsinghua University-Tel Aviv University research team and was led by Prof. Quanshui Zheng of the Tsinghua Center for Nano and Micro Mechanics and Prof. Michael Urbakh of the TAU School of Chemistry, both of the TAU-Tsinghua XIN Center, in collaboration with Prof. Francois Grey of the University of Geneva.

A July 5, 2015 American Friends of Tel Aviv University news release (also on EurekAlert), which originated the news item, provides more details about the work,

“We’ve discovered that very small vibrations help materials, whether wet or dry, slide more smoothly past each other,” said Prof. Urbakh. “Through phonon oscillations — vibrations of water-carrying nanotubes — water transport can be enhanced, and sanitation and desalination improved. Water filtration systems require a lot of energy due to friction at the nano-level. With these oscillations, however, we witnessed three times the efficiency of water transport, and, of course, a great deal of energy saved.”

The research team managed to demonstrate how, under the right conditions, such vibrations produce a 300% improvement in the rate of water diffusion by using computers to simulate the flow of water molecules flowing through nanotubes. The results have important implications for desalination processes and energy conservation, e.g. improving the energy efficiency for desalination using reverse osmosis membranes with pores at the nanoscale level, or energy conservation, e.g. membranes with boron nitride nanotubes.

Crowdsourcing the solution

The project, initiated by IBM’s World Community Grid, was an experiment in crowdsourced computing — carried out by over 150,000 volunteers who contributed their own computing power to the research.

“Our project won the privilege of using IBM’s world community grid, an open platform of users from all around the world, to run our program and obtain precise results,” said Prof. Urbakh. “This was the first project of this kind in Israel, and we could never have managed with just four students in the lab. We would have required the equivalent of nearly 40,000 years of processing power on a single computer. Instead we had the benefit of some 150,000 computing volunteers from all around the world, who downloaded and ran the project on their laptops and desktop computers.

“Crowdsourced computing is playing an increasingly major role in scientific breakthroughs,” Prof. Urbakh continued. “As our research shows, the range of questions that can benefit from public participation is growing all the time.”

The computer simulations were designed by Ming Ma, who graduated from Tsinghua University and is doing his postdoctoral research in Prof. Urbakh’s group at TAU. Ming catalyzed the international collaboration. “The students from Tsinghua are remarkable. The project represents the very positive cooperation between the two universities, which is taking place at XIN and because of XIN,” said Prof. Urbakh.

Other partners in this international project include researchers at the London Centre for Nanotechnology of University College London; the University of Geneva; the University of Sydney and Monash University in Australia; and the Xi’an Jiaotong University in China. The researchers are currently in discussions with companies interested in harnessing the oscillation knowhow for various commercial projects.

 

Here’s a link to and a citation for the paper,

Water transport inside carbon nanotubes mediated by phonon-induced oscillating friction by Ming Ma, François Grey, Luming Shen, Michael Urbakh, Shuai Wu,    Jefferson Zhe Liu, Yilun Liu, & Quanshui Zheng. Nature Nanotechnology (2015) doi:10.1038/nnano.2015.134 Published online 06 July 2015

This paper is behind a paywall.

Final comment, I find it surprising that they used labour and computing power from 150,000 volunteers and didn’t offer open access to the paper. Perhaps the volunteers got their own copy? I certainly hope so.

Optical nanoantennas open up lab-on-a-chip possibilities

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A Feb. 24, 2015 news item on Nanowerk describes nanoantenna research coming out of Australia (Note: A link has been removed),

Newly developed tiny antennas, likened to spotlights on the nanoscale, offer the potential to measure food safety, identify pollutants in the air and even quickly diagnose and treat cancer, according to the Australian scientists who created them. The new antennas are cubic in shape. They do a better job than previous spherical ones at directing an ultra-narrow beam of light where it is needed, with little or no loss due to heating and scattering, they say.

In a paper published in the Journal of Applied Physics (“Optically resonant magneto-electric cubic nanoantennas for ultra-directional light scattering”), Debabrata Sikdar of Monash University in Victoria, Australia, and colleagues describe these and other envisioned applications for their nanocubes in “laboratories-on-a-chip.” …

A Feb. 24, 2015 American Institute of Physics news release on EurekAlert, which originated the news item, describes the work in detail,

… The cubes, composed of insulating, rather than conducting or semiconducting materials as were the spherical versions, are easier to fabricate as well as more effective, he [Sikdar] says.

Sikdar’s paper presents analysis and simulation of 200-nanometer dielectric (nonconductive) nanoncubes placed in the path of visible and near-infrared light sources. The nanocubes are arranged in a chain, and the space between them can be adjusted to fine-tune the light beam as needed for various applications. As the separation between cubes increases, the angular width of the beam narrows and directionality improves, the researchers say.

“Unidirectional nanoantennas induce directionality to any omnidirectional light emitters like microlasers, nanolasers or spasers, and even quantum dots,” Sikdar said in an interview. Spasers are similar to lasers, but employ minute oscillations of electrons rather than light. Quantum dots are tiny crystals that produce specific colors, based on their size, and are widely used in color televisions. “Analogous to nanoscale spotlights, the cubic antennas focus light with precise control over direction and beam width,” he said. [emphasis mine]

The new cubic nanoantennas have the potential to revolutionize the infant field of nano-electromechanical systems (NEMS). “These unidirectional nanoantennas are most suitable for integrated optics-based biosensors to detect proteins, DNA, antibodies, enzymes, etc., in truly portable lab-on-a-chip platforms of the future,” Sikdar said. “They can also potentially replace the lossy on-chip IC (integrated circuit) interconnects, via transmitting optical signals within and among ICs, to ensure ultrafast data processing while minimizing device heating,” he added. [emphasis mine]

Sikdar and his colleagues plan to begin constructing unidirectional cubic NEMS antennas in the near future at the Melbourne Center for Nanofabrication. “We would like to collaborate with other research groups across the world, making all these wonders possible,” he said.

I’m glad the writer included Sikdar’s explanation of spasers and quantum dots and thank them both for a new word, “lossy.” Here’s a link to and a citation for the paper,

Optically resonant magneto-electric cubic nanoantennas for ultra-directional light scattering by Debabrata Sikdar, Wenlong Cheng, and Malin Premaratne. J. Appl. Phys. 117, 083101 (2015); http://dx.doi.org/10.1063/1.4907536

This article is open access.

Graphene oxide in liquid crystal droplets could be used in medical applications

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Not everyone has been seduced by all the talk of graphene and electronics, it seems researchers at Monash University in Australia have researched graphene with an eye to its potential use in medical applications. From an Aug. 6, 2014 news item on ScienceDaily,

A chance discovery about the ‘wonder material’ graphene — already exciting scientists because of its potential uses in electronics, energy storage and energy generation — takes it a step closer to being used in medicine and human health.

Researchers from Monash University have discovered that graphene oxide sheets can change structure to become liquid crystal droplets spontaneously and without any specialist equipment.

With graphene droplets now easy to produce, researchers say this opens up possibilities for its use in drug delivery and disease detection.

The findings, published in the journal ChemComm, build on existing knowledge about graphene. One of the thinnest and strongest materials known to man, graphene is a 2D sheet of carbon just one atom thick. With a ‘honeycomb’ structure the ‘wonder material’ is 100 times stronger than steel, highly conductive and flexible.

An Aug. 6, 2014 Monash University media release (also on EurekAlert but dated Aug. 5, 2014), which originated the news item, describes the findings in more detail,

Dr Mainak Majumder from the Faculty of Engineering said because graphene droplets change their structure in response to the presence of an external magnetic field, it could be used for controlled drug release applications.

“Drug delivery systems tend to use magnetic particles which are very effective but they can’t always be used because these particles can be toxic in certain physiological conditions,” Dr Majumder said.

“In contrast, graphene doesn’t contain any magnetic properties. This combined with the fact that we have proved it can be changed into liquid crystal simply and cheaply, strengthens the prospect that it may one day be used for a new kind of drug delivery system.”

Usually atomisers and mechanical equipment are needed to change graphene into a spherical form. In this case all the team did was to put the graphene sheets in a solution to process it for industrial use. Under certain pH conditions they found that graphene behaves like a polymer – changing shape by itself.

First author of the paper, Ms Rachel Tkacz from the Faculty of Engineering, said the surprise discovery happened during routine tests.

“To be able to spontaneously change the structure of graphene from single sheets to a spherical assembly is hugely significant. No one thought that was possible. We’ve proved it is,” Ms Tkacz said.

“Now we know that graphene-based assemblies can spontaneously change shape under certain conditions, we can apply this knowledge to see if it changes when exposed to toxins, potentially paving the way for new methods of disease detection as well.”

Commonly used by jewelers, the team used an advanced version of a polarised light microscope based at the Marine Biological Laboratory, USA, to detect minute changes to grapheme.

Dr Majumder said collaborating with researchers internationally and accessing some of the most sophisticated equipment in the world, was instrumental to the breakthrough discovery.

“We used microscopes similar to the ones jewelers use to see the clarity of precious gems. The only difference is the ones we used are much more precise due to a sophisticated system of hardware and software. This provides us with crucial information about the organisation of graphene sheets, enabling us to recognise these unique structures,” Dr Majumder said.

Dr Majumder and his team are working with graphite industry partner, Strategic Energy Resources Ltd and an expert in polarized light imaging, Dr. Rudolf Oldenbourg from the Marine Biological Laboratory, USA, to explore how this work can be translated and commercialised.

Here’s a link to and a citation for the paper,

pH dependent isotropic to nematic phase transitions in graphene oxide dispersions reveal droplet liquid crystalline phases by Rachel Tkacz, Rudolf Oldenbourg, Shalin B. Mehta, Morteza Miansari, Amitabh Verma, and Mainak Majumder. Chem. Commun., 2014,50, 6668-6671 DOI: 10.1039/C4CC00970C First published online 06 May 2014

This paper is behind a paywall.

Move over laser—the graphene/carbon nanotube spaser is here, on your t-shirt

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This research graphene/carbon nanotube research comes from Australia according to an April 16, 2014 news item on Nanowerk,

A team of researchers from Monash University’s [Australia] Department of Electrical and Computer Systems Engineering (ECSE) has modelled the world’s first spaser …

An April 16, 2014 Monash University news release, which originated the new item, describes the spaser and its relationship to lasers,,

A new version of “spaser” technology being investigated could mean that mobile phones become so small, efficient, and flexible they could be printed on clothing.

…

A spaser is effectively a nanoscale laser or nanolaser. It emits a beam of light through the vibration of free electrons, rather than the space-consuming electromagnetic wave emission process of a traditional laser.

The news release also provides more details about the graphene/carbon nanotube spaser research and the possibility of turning t-shirts into telephones,

PhD student and lead researcher Chanaka Rupasinghe said the modelled spaser design using carbon would offer many advantages.

“Other spasers designed to date are made of gold or silver nanoparticles and semiconductor quantum dots while our device would be comprised of a graphene resonator and a carbon nanotube gain element,” Chanaka said.

“The use of carbon means our spaser would be more robust and flexible, would operate at high temperatures, and be eco-friendly.

“Because of these properties, there is the possibility that in the future an extremely thin mobile phone could be printed on clothing.”

Spaser-based devices can be used as an alternative to current transistor-based devices such as microprocessors, memory, and displays to overcome current miniaturising and bandwidth limitations.

The researchers chose to develop the spaser using graphene and carbon nanotubes. They are more than a hundred times stronger than steel and can conduct heat and electricity much better than copper. They can also withstand high temperatures.

Their research showed for the first time that graphene and carbon nanotubes can interact and transfer energy to each other through light. These optical interactions are very fast and energy-efficient, and so are suitable for applications such as computer chips.

“Graphene and carbon nanotubes can be used in applications where you need strong, lightweight, conducting, and thermally stable materials due to their outstanding mechanical, electrical and optical properties. They have been tested as nanoscale antennas, electric conductors and waveguides,” Chanaka said.

Chanaka said a spaser generated high-intensity electric fields concentrated into a nanoscale space. These are much stronger than those generated by illuminating metal nanoparticles by a laser in applications such as cancer therapy.

“Scientists have already found ways to guide nanoparticles close to cancer cells. We can move graphene and carbon nanotubes following those techniques and use the high concentrate fields generated through the spasing phenomena to destroy individual cancer cells without harming the healthy cells in the body,” Chanaka said

Here’s a link to and a citation for the paper,

Spaser Made of Graphene and Carbon Nanotubes by Chanaka Rupasinghe, Ivan D. Rukhlenko, and Malin Premaratne. ACS Nano, 2014, 8 (3), pp 2431–2438. DOI: 10.1021/nn406015d Publication Date (Web): February 23, 2014
Copyright © 2014 American Chemical Society

This paper is behind a paywall.

Prussian blue nanocubes and ultralightweight iron oxide materials

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The research itself concerns the synthesis of ultralight iron oxide frameworks but really caught my attention was the image used to illustrate the work and the term ‘Prussian blue nanocubes’,

[downloaded from http://www.wiley-vch.de/util/hottopics/mesoporous/]

[downloaded from http://www.wiley-vch.de/util/hottopics/mesoporous/]

I believed the image is meant to indicate an ultralight iron anvil resting on the head of a rose-like blossom (I was mostly wrong) as you’ll see in this Feb. 25, 2014 news item on Nanowerk (Note: A link has been removed),

Adsorption, catalysis, or substrates for tissue growth: porous materials have many potential applications. In the journal Angewandte Chemie (“Ultralight Mesoporous Magnetic Frameworks by Interfacial Assembly of Prussian Blue Nanocubes”), a team of Chinese and Australian researchers has now introduced a method for the synthesis of ultralight three-dimensional (3D) iron oxide frameworks with two different types of nanoscopic pores and tunable surface properties. This superparamagnetic material can be cut into arbitrary shapes and is suitable for applications such as multiphase catalysis and the removal of heavy metal ions and oil from water.

Materials with hierarchically organized pore systems—meaning that the walls of macropores with diameters in the micrometer range contain mesopores of just a few nanometers—are high on the wish lists of materials researchers. The advantages of these materials include their high surface area and the easy accessibility of the small pores through the larger ones. The great desirability of these materials is matched by the degree of difficulty in producing them on an industrial scale.

Scientists at Fudan University (China) and Monash University (Australia) have now successfully produced an ultralight iron oxide framework with 250 µm and 18 nm pores in a process that can be used on an industrial scale. A team led by Gengfeng Zheng and Dongyuan Zhao used highly porous polyurethane sponges as a “matrix”, which were soaked with yellow potassium hexacyanoferrate (K4[Fe(CN)6]). Subsequent hydrolysis resulted in cubic nanocrystals of Prussian blue (iron hexacyanoferrate), a dark blue pigment, which were deposited all over the surfaces of the sponge. The polyurethane sponge was then fully burned away through pyroloysis and the Prussian blue was converted to iron oxide. The result is a 3D framework of iron oxide cubes that are in turn made of iron oxide nanoparticles and contain mesopores. The material is so light that the researchers were able to balance a 240 cm3 piece on an oleander blossom.

As for Prussian blue, it’s a term I associate with portraits and landscapes. Actually, Prussian blue is a little more than that (from the Prussian blue entry on wiktionary.org),

Prussian blue (plural Prussian blues)

(inorganic chemistry) An insoluble dark, bright blue pigment, ferric ferrocyanide (equivalent to ferrous ferricyanide), used in painting and dyeing, and as an antidote for certain kinds of heavy metal poisoning.
A moderate to rich blue colour, tinted with deep greenish blue.

Here’s a sample of the colour from the wiktionary entry,

[downloaded from http://en.wiktionary.org/wiki/Prussian_blue]

[downloaded from http://en.wiktionary.org/wiki/Prussian_blue]

Prussian Blue was also the name for a short-lived white nationalist band (from the Prussian Blue essay on Wikipedia; Note: Links have been removed),

Prussian Blue was an American white nationalist pop pre-teen duo formed in early 2003 by April Gaede, mother of Lynx Vaughan Gaede[1] and Lamb Lennon Gaede,[2] sororal twins born on June 30, 1992, in Bakersfield, California.[3] The twins referred to the Holocaust as a myth[4] and their group was described as racist and white supremacist in nature.[5][6]

Lynx and Lamb were about 14 when they decided that they wanted to cease touring. In 2011, in an interview with The Daily, the twins renounced their previous politics.[7] Lamb was quoted saying, “I’m not a white nationalist anymore. My sister and I are pretty liberal now.”

Getting back to the research at hand, here’s a link to and a citation for the research into ultralight iron oxide frameworks,

Ultralight Mesoporous Magnetic Frameworks by Interfacial Assembly of Prussian Blue Nanocubes by Biao Kong, Jing Tang, Zhangxiong Wu, Jing Wei, Hao Wu, Yongcheng Wang, Prof. Gengfeng Zheng, & Prof. Dongyuan Zhao. Angewandte Chemie International Edition Article first published online: 12 FEB 2014 DOI: 10.1002/anie.201308625

Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

I really wasn’t expecting to trip across information about a holocaust-denying pre-teen pop duo (who’ve since renounced those views) in a post regarding research on iron oxide and Prussian blue nanocubes that was published in a German chemistry journal. I’m not sure this can be called ironic but it certainly has that quality.