Aurelia Butler

The virus responsible for E. coli infection has a secret weapon: teamwork.
Always scrappy in its bid for survival, the virus alights on an unassuming host cell and grips the surface with the business end of its tubular tail. Then, the proteins in the tail contract in unison, flattening its structure like a stepped-on spring and reeling the virus’s body in for the critical strike.
Thanks to the proteins’ teamwork, the tail can flex and flatten with ease. This process, called molecular cooperativity, is often observed in nature but rarely seen in non-living systems.
Researchers at the Beckman Institute for Advanced Science and Technology discovered a way to trigger this cooperative behavior in organic semiconductors. The energy- and time-saving phenomenon may help enhance the performance of smartwatches, solar cells, and other organic electronics.
Their work was accepted for publication in Nature Communications.
“Our research brings semiconductors to life by unlocking the same dynamic qualities that natural organisms like viruses use to adapt and survive,” said Ying Diao, a researcher at the Beckman Institute and a coauthor of the study.

Viruses may have mastered molecular cooperativity, but the same cannot be said of crystals: non-living molecular structures classified by their symmetry. Though aesthetically pleasing, the molecules that comprise crystalline structures have diva-like dispositions and seldom work together. Instead, they test researchers’ patience by plodding through structural transitions one molecule at a time — a process famously demonstrated by diamonds growing from carbon, which demands blistering heat, intense pressure, and thousands of years sequestered deep beneath the earth.
“Imagine taking down an elaborate domino display brick by brick. It’s exhausting and laborious, and once you’ve finished, you would most likely not have the energy to try it again,” said Daniel Davies, the study’s lead author and a researcher at the Beckman Institute at the time of the study.
By contrast, cooperative transitions occur when molecules shift their structure in synchrony, like a row of dominoes flowing seamlessly to the floor. The collaborative method is fast, energy-efficient, and easily reversible — it’s why the virus responsible for E. coli infection can tirelessly contract its protein-packed tail with little energy lost.
For a long time, researchers have struggled to replicate this cooperative process in non-living systems to reap its time- and energy-saving benefits. This problem was of particular interest to Diao and Davies, who wondered how molecular teamwork might impact the electronics sector.
“Molecular cooperativity helps living systems operate quickly and efficiently,” Davies said. “We thought, ‘If the molecules in electronic devices worked together, could those devices display those same benefits?'”
Diao and Davies study organic electronic devices, which rely on semiconductors made from molecules like hydrogen and carbon rather than inorganic ones like silicon, a ubiquitous ingredient in the laptops, desktops, and smart devices saturating the market today.

“Since organic electronics are made from the same basic elements as living beings, like people, they unlock many new possibilities for applications,” said Diao, who is also an associate professor of chemical and biological engineering at the University of Illinois Urbana-Champaign. “In the future, organic electronics might be able to attach to our brains to enhance cognition or, be worn like a Band-aid to convert our body heat into electricity.”
Diao studies the design of solar cells: wafer-thin window clings that soak up sunlight to convert into electricity. Organic semiconductors that can flex without breaking and contour to human skin would likewise be “an important part of the future of organic electronic devices,” Davies said.
It’s a bright future indeed, but an important step toward designing dynamic organic electronics like these is fashioning dynamic organic semiconductors. And for that to happen, the semiconductor molecules must cooperate.
Dominoes inspired the researchers’ approach to trigger molecular teamwork in a semiconductor crystal. They discovered that rearranging the clusters of hydrogen and carbon atoms spooling out from a molecule’s core — otherwise known as alkyl chains — causes the molecular core itself to tilt, triggering a crystal-wide chain of collapse the researchers refer to as an “avalanche.”
“Just like dominoes, the molecules don’t move from where they are fixed. Only their tilt changes,” Davies said.
But tilting a string of molecules is neither as easy nor as tactile as picking up a domino and rotating it 90 degrees. On a scale much smaller than a plastic game piece, the researchers gradually applied heat to the molecule’s alkyl chain; the increased temperature induced the domino-like effect.
Using heat to rearrange the molecules’ alkyl chains also caused the crystal itself to shrink — just like the virus’s tail prior to E. coli infection. In an electronic device, this property translates to an easy, temperature-induced on-off switch.
The applications of this discovery have yet to be fully realized; for now, the researchers are thrilled with the first step.
“The most exciting part was being able to observe how these molecules are changing and how their structure is evolving throughout these transitions,” Davies said.
Unlocking the potential of molecular collaboration was possible through teamwork on an international scale, with contributing researchers hailing from Purdue University, the Chinese Academy of Sciences, and Argonne National Laboratory. Raman spectroscopy was conducted in the Beckman Institute Microscopy Suite. More

An international team of scientists is developing an inkable nanomaterial that they say could one day become a spray-on electronic component for ultra-thin, lightweight and bendable displays and devices.
The material, zinc oxide, could be incorporated into many components of future technologies including mobile phones and computers, thanks to its versatility and recent advances in nanotechnology, according to the team.
RMIT University’s Associate Professor Enrico Della Gaspera and Dr Joel van Embden led a team of global experts to review production strategies, capabilities and potential applications of zinc oxide nanocrystals in the journal Chemical Reviews, a high-impact international journal.
Professor Silvia Gross from the University of Padova in Italy and Associate Professor Kevin Kittilstved from the University of Massachusetts Amherst in the United States are co-authors.
“Progress in nanotechnology has enabled us to greatly improve and adapt the properties and performances of zinc oxide by making it super small, and with well-defined features,” said Della Gaspera, from RMIT’s School of Science.
“Tiny and versatile particles of zinc oxide can now be prepared with exceptional control of their size, shape and chemical composition at the nanoscale,” said van Embden, also from RMIT’s School of Science.

“This all leads to precise control of the resulting properties for countless applications in optics, electronics, energy, sensing technologies and even microbial decontamination.”
Sky’s the limit with spray-on electronics
The zinc oxide nanocrystals can be formulated into ink and deposited as an ultra-thin coating. The process is like ink-jet printing or airbrush painting, but the coating is hundreds to thousands of times thinner than a conventional paint layer.
“These coatings can be made highly transparent to visible light, yet also highly electrically conductive – two fundamental characteristics needed for making touchscreen displays,” Della Gaspera said.
The nanocrystals can also be deposited at low temperature, allowing coatings on flexible substrates, such as plastic, that are resilient to flexing and bending, the team says.

The team is ready to work with industry to explore potential applications using their techniques to make these nanomaterial coatings.
What is zinc oxide and how can it be used?
Zinc is an abundant element in the Earth’s crust and more abundant than many other technologically relevant metals, including tin, nickel, lead, tungsten, copper and chromium.
“Zinc is cheap and widely used by various industries already, with global annual production in the millions of tonnes,” van Embden said.
Zinc oxide is an extensively studied material, with initial scientific studies being conducted from the beginning of the 20th century.
“Zinc oxide gained a lot of interest in the 1970s and 1980s due to progress in the semiconductor industry. And with the advent of nanotechnology and advancement in both syntheses and analysis techniques, zinc oxide has rapidly risen as one of the most important materials of this century,” Della Gaspera said.
Zinc oxide is also safe, biocompatible and found already in products such as sunscreens and cosmetics.
Potential applications, other than bendable electronics, that could use zinc oxide nanocrystals include: self-cleaning coatings antibacterial and antifungal agents sensors to detect ultraviolet radiation electronic components in solar cells and light emitting devices (LED) transistors, which are miniature components that control electrical signals and are the foundation of modern electronics sensors that could be used to detect harmful gases for residential, industrial and environmental applications.Next steps
Scaling up the team’s approach from the lab to an industrial setting would require working with the right partners, Della Gaspera said.
“Scalability is a challenge for all types of nanomaterials, zinc oxide included,” he said.
“Being able to recreate the same conditions that we achieve in the laboratory, but with much larger reactions, requires both adapting the type of chemistry used and engineering innovations in the reaction setup.”
In addition to these scalability challenges, the team needs to address the shortfall in electrical conductivity that nanocrystal coatings have when compared to industrial benchmarks, which rely on more complex physical depositions. The intrinsic structure of the nanocrystal coatings, which enables more flexibility, limits the ability of the coating to conduct electricity efficiently.
“We and other scientists around the world are working towards addressing these challenges and good progress is being made,” Della Gaspera said.
He sees great opportunities to collaborate with other organisations and industry partners to tackle these kinds of challenges.
“I am confident that, with the right partnership, these challenges can be solved,” Della Gaspera said. More

A recent study that examined the relationship between artificial intelligence (AI) and law enforcement underscores both the need for law enforcement agencies to be involved in the development of public policies regarding AI — such as regulations governing autonomous vehicles — and the need for law enforcement officers to better understand the limitations and ethical challenges of AI technologies.
“Law enforcement agencies have a crucial role to play in implementing public policies related to AI technologies,” says Veljko Dubljevi?, corresponding author of the study and an associate professor of science, technology and society at North Carolina State University.
“For example, officers will need to know how to proceed if they pull over a vehicle being driven autonomously for a traffic violation. For that matter, they will need to know how to pull over a vehicle being driven autonomously. Because of their role in maintaining public order, it’s important for law enforcement to have a seat at the table in crafting these policies.”
“In addition, there are a number of AI-powered technologies that are already in use by law enforcement agencies that are designed to help them prevent and respond to crime,” says Ronald Dempsey, first author of the study and a former graduate student at NC State. “These range from facial recognition technologies to technologies designed to detect gunshots and notify relevant law enforcement agencies.
“However, our study suggests that many officers do not understand how these technologies work, which makes it difficult or impossible for them to appreciate the limitations and ethical risks of those technologies. And that can pose significant problems for both law enforcement and the public.”
For this study, the researchers conducted in-depth interviews with 20 law enforcement professionals who work in North Carolina. The interviews addressed a range of issues, including the values and qualities that the study participants felt were critical for law enforcement officers.

While there was no consensus across a majority of study participants, there were several characteristics that cropped up repeatedly as important qualities for a law enforcement professional, with integrity, honesty and empathy being cited most often.
“Understanding what law enforcement deems to be desirable characteristics in officers is valuable, because these characteristics can inform the development of responsible design guidelines for AI technologies that law enforcement will use,” Dempsey says.
“Design guidelines can be used to inform AI decision-making, and it is easier for end users to work with AI tools if the values guiding AI decisions are consistent — or at least not in conflict — with the values of the end users,” says Dubljevi?.
The researchers also asked study participants about their views on AI in general, as well as existing and emerging AI technologies.
“We found that study participants were not familiar with AI, or with the limitations of AI technologies,” says Jim Brunet, co-author of the study and director of NC State’s Public Safety Leadership Initiative. “This included AI technologies that participants had used on the job, such as facial recognition and gunshot detection technologies. However, study participants expressed support for these tools, which they felt were valuable for law enforcement.”
The study participants also expressed concern about the future of autonomous vehicles, and what challenges they may pose to the law enforcement community.
“However, study participants did say that they would welcome public use of autonomous vehicles if that would reduce car accidents,” says Dubljevi?. “Specifically, the participants welcomed the idea of spending less time responding to vehicle accidents, which would allow them to focus on addressing crime.”
“There are always dangers when law enforcement adopts technologies that were not developed with law enforcement in mind,” says Brunet. “This certainly applies to AI technologies such as facial recognition. As a result, it’s critical for law enforcement officials to have some training in the ethical dimensions surrounding the use of these AI technologies. For example, where a law enforcement agency chooses to deploy AI tools will affect which portions of the public are subject to additional scrutiny.”
“It’s also important to understand that AI tools are not foolproof,” says Dubljevi?. “AI is subject to limitations. And if law enforcement officials don’t understand those limitations, they may place more value on the AI than is warranted — which can pose ethical challenges in itself.” More

New research from Carnegie Mellon University’s Robotics Institute (RI) aims to increase autonomy for individuals with such motor impairments by introducing a head-worn device that will help them control a mobile manipulator. Teleoperated mobile manipulators can aid individuals in completing daily activities, but many existing technologies like hand-operated joysticks or web interfaces require a user to have substantial fine motor skills to effectively control them. Research led by robotics Ph.D. student Akhil Padmanabha offers a new device equipped with a hands-free microphone and head-worn sensor that allows users to control a mobile robot via head motion and speech recognition.
More than five million people in the United States live with some form of paralysis and may encounter difficulties completing everyday tasks, like grabbing a glass of water or putting on clothes. New research from Carnegie Mellon University’s Robotics Institute (RI) aims to increase autonomy for individuals with such motor impairments by introducing a head-worn device that will help them control a mobile manipulator.
Teleoperated mobile manipulators can aid individuals in completing daily activities, but many existing technologies like hand-operated joysticks or web interfaces require a user to have substantial fine motor skills to effectively control them. Research led by robotics Ph.D. student Akhil Padmanabha offers a new device equipped with a hands-free microphone and head-worn sensor that allows users to control a mobile robot via head motion and speech recognition. Head-Worn Assistive Teleoperation (HAT) requires fewer fine motor skills than other interfaces, offering an alternative for users who face constraints with technology currently on the market.
In addition to Padmanabha, the research team includes Qin Wang, Daphne Han, Jashkumar Diyora, Kriti Kacker, Hamza Khalid, Liang-Jung Chen, Carmel Majidi and Zackory Erickson. In a human study, participants both with and without motor impairments performed multiple household and self-care tasks with low error rates, minimal effort and a high perceived ease of use. The research team will present their paper, “HAT: Head-Worn Assistive Teleoperation of Mobile Manipulators,” at the IEEE’s International Conference on Robotics and Automation in London this spring. More

When a family of five-ton elephants stomps and chomps its waythrough your crops, there’s only one winner. And in the central African nation of Gabon, farmers are getting fed up with the giant animals trampling their fields — and their livelihoods.
In conservation terms, Gabon is a success story — protected areas and tough anti-poaching measures have allowed the numbers of critically endangered African forest elephants to stabilize. But with food prices rising, anti-elephant protests have been spiking too. “Some people cannot farm anymore — the elephants are eating so much of their crops,” Gabon’s environment minister Lee White told Reuters in 2022. “It has become a political issue and is eroding support for conservation and for the president (and) government.”
As Gabon’s leaders have learned, balancing conservation and agriculture isn’t easy: tilt policies in favor of farmers, and important habitats or species could be lost; tip efforts toward animals or land, and people may lose their livelihoods. Paying farmers to support the environment might seem like an easy answer — incentivizing them to conserve habitats. But a new study led by Andrew Reid Bell, a Boston University College of Arts & Sciences assistant professor of Earth & environment, has found payments don’t always reconcile the tension between agricultural production and the planet’s health.
With an international team of researchers, he used video games to test how farmers around the world react when faced with conservation dilemmas — like traipsing elephants in Gabon, hungry geese in Scotland, and crop pests in Cambodia. For the most part, payments designed to motivate eco-friendly behavior weren’t a reliable panacea: if they boosted pro-conservation work, they usually dented agricultural outputs. The study did, though, discover one seemingly surefire way of improving conservation and production: including more women in decision-making. Their involvement boosted cooperation between farmers on environmental issues and increased output. The results were published in Communications Earth & Environment.
“It informs this bigger story of finding ways to better empower women in agricultural contexts around the world,” says Bell.
Playing Games, Testing Dilemmas
To see how farmers and pastoralists behaved when confronted with a conservation predicament, Bell designed and built three games using the modeling tool NetLogo. Each game posed a different dilemma for players: GooseBump, decide to let wildlife damage crops, scare animals onto other farms, or use lethal control; NonCropShare, choose between using pesticides or natural pest control; and SharedSpace, balance growing crops while conserving forest and managing fallow land. The multiplayer games were played on tablets in seven countries, from the Orkney Islands off the northernmost tip of Scotland to Madagascar to Vietnam.

“We were looking at how players sharing a space will coordinate and any player has equal opportunity to lead the group, follow, or encourage a particular result,” says Bell, a resource ecology and management expert who specializes in building computer models and behavioral experiments to examine issues like agricultural development and water use.
It turned out that pro-environment payments can work in some situations — usually if there’s a clear agricultural benefit, such as when neighboring farmers coordinate on leaving areas fallow, boosting soil resiliency and, therefore, their overall crop yield. But when the benefits take time or don’t quickly improve output, payments aren’t effective: increased biodiversity might help society in the long term, but doesn’t change this year’s harvest, or next year’s.
“The challenge in many lower-income environments is that a lot of the payoffs to conservation agriculture emerge on four- to eight-year time horizons,” says Bell, “which is often beyond the planning horizon of farmers who are thinking two or three months ahead, meeting more immediate needs. It’s a mismatch.”
The first program the team created was NonCropShare, a pest control game that was played by farmers in Cambodia and Vietnam.
“You could do well by just spraying everything and avoiding pest damage,” says Bell, “but you could do equally well by coordinating on maintaining natural enemies — parasitic wasps, spiders, or dragonflies that would eat the pests. The challenge with that coordinated solution is that if anybody defected, everybody else would be worse off. The question was, how much do we have to incentivize that pro-environmental solution to tip the balance?”
The answer depended on the country. In Vietnam, payments nudged farmers into cooperation, while in Cambodia they just made things worse. “The approach to farming — in the game, at least — wasn’t a good match for the payments” in Cambodia, says Bell, “and the mix of strategies that people employed when we offered payments left the landscapes worse off than if we hadn’t offered anything.” The other two games reflected the overall trend.

From Mario Kart to Human Behavior
It’s not the first time Bell has mixed video games and conservation studies. In one past paper, he drew lessons from Nintendo’s Mario Kart, looking at the way it gives better bonuses to dawdling players to keep races even. He says games are useful as an experimental tool, too, allowing researchers and policymakers to trial a theory or an approach to an issue when a field test is either impractical or too costly. And they help him dig into human behavior and decision-making in deeper ways than a survey or interview can: “It’s really common people can’t tell you what they’re thinking,” says Bell, who’s also affiliated with the BU Center on Forced Displacement, “or how they do something, or they don’t want to.”
And in conservation, some of the dilemmas faced by farmers aren’t exactly polite dinner table topics — not many people will admit to killing wildlife, but they might debate the action in an impersonal video game.
“Dynamic games like this can help desensitize illegal activities, such as lethal control or forest clearing, in a way conventional tools cannot,” says Sarobidy Rakotonarivo, an author on the paper and environmental socioeconomist based in Madagascar. “These are often criminalized activities that farmers are unwilling to talk about for fear of prosecution. The games provide a safer environment to get them to talk openly.”
When it comes to our changing planet, says Bell, we have a lot of big data — satellite images, gauges on land, sea, and air — but not nearly as much information on human decision-making.
“We can talk about sea surface temperature or rainfall anomalies, about deviation from a mean, but we don’t have that with social data — we don’t know much about what people do,” he says. With one exception: when disaster, like a famine, strikes. Then researchers descend and grab as much information as possible about what went wrong. “But we miss all these stories where things are going just fine, we miss our ability to explain why that is. So, we need ways to better engage with people to capture their decisions.”
Empower Women
Including women in farming groups was one human factor that made a lot of things go right, according to Bell’s study. Whenever a group had increased gender diversity, production and pro-environment outcomes improved. In their paper, the researchers write that “mixed gender groups may lead to better natural resource management.” They also showed that when the players built strong relationships and trusted each other, conservation efforts got a boost.
“We need to be better at empowering women in agricultural contexts,” says Bell. “It’s hard, because, in part, you see all these cases where people invest in a crop that’s traditionally a women’s crop, it succeeds, then becomes a men’s crop.”
The International Food Policy Research Institute — whose senior research fellow Wei Zhang was a coauthor on the latest study — has found protecting women’s rights to own land, improving their access to credit and financial services, and giving them more decision-making power can all help.
And, adds Rakotonarivo, an African Research Initiative for Scientific Excellence research fellow, we also need to step up when it comes to listening to — and trusting — the people most impacted by conservation policies.
“Small-scale rural farmers, although often portrayed as having low levels of education, are capable of wise choices,” she says. “They are not the key obstacles to conservation as often assumed. Obstacles may be simply broader social barriers, such as very low agricultural productivity, that need to be addressed by other types of programs.”
Rakotonarivo says that ignoring farmers when developing pro-environment interventions will only lead to failure; if their needs aren’t considered, programs “might fail to mitigate conservation conflicts through lack of engagement, uptake, and follow-through.” Although many problems — farmers killing pest animals or clearing forests — are “commonly framed as human-wildlife conflicts,” she says, the issues may be better addressed by looking at the “more complex social conflicts between different social groups.”
In their paper, the researchers recommend policymakers consider programs that have both conservation and production goals, rather than just one of those goals, or that include bonuses for cooperation among groups of farmers. They also highlight improved access to insurance programs that cover the risks of pro-environment efforts, ensuring payouts, for example, when tigers or lions raid livestock. But most of all, they write, rather than being prescriptive with program suggestions, “we only wish to highlight the challenges of aligning encouragements simultaneously with environment and livelihood goals.”
There is one innovative, nature-based solution in the paper though that might be of particular interest to the farmers of Gabon: bee fences. These makeshift, homespun barriers are hung with beehives every 10 meters or so. If an animal tries to crash through, the bees quickly give them a reason to turn around. And while popular culture might show elephants cowering when a mouse scuttles by, it’s bees they really don’t like. If the elephants, preoccupied by bees, don’t trample and gobble the crops, the farmers are more likely to help protect the animals.
“Conservation often comes at the cost of rural livelihoods,” says Rakotonarivo. “Policymakers, and especially the conservation community, need to be deliberate about the joint people and environment goals of an intervention.”
This study was primarily supported by the CGIAR Research Program on Water, Land, and Ecosystems; the CGIAR Research Program on Policies, Institutions, and Markets; and the European Research Council. The research team also included Apurva Bhargava, New York University; A. Bradley Duthie and Adams Kipchumba, University of Stirling, Scotland; Becca Sargent, Newcastle University, England; and Spike Lewis, Bangor University, Wales. More

For the first time, scientists at the University of Sydney and the University of Basel in Switzerland have demonstrated the ability to manipulate and identify small numbers of interacting photons — packets of light energy — with high correlation.
This unprecedented achievement represents an important landmark in the development of quantum technologies. It is published today in Nature Physics.
Stimulated light emission, postulated by Einstein in 1916, is widely observed for large numbers of photons and laid the basis for the invention of the laser. With this research, stimulated emission has now been observed for single photons.
Specifically, the scientists could measure the direct time delay between one photon and a pair of bound photons scattering off a single quantum dot, a type of artificially created atom.
“This opens the door to the manipulation of what we can call ‘quantum light’,” Dr Sahand Mahmoodian from the University of Sydney School of Physics and joint lead author of the research said.
Dr Mahmoodian said: “This fundamental science opens the pathway for advances in quantum-enhanced measurement techniques and photonic quantum computing.”
By observing how light interacted with matter more than a century ago, scientists discovered light was not a beam of particles, nor a wave pattern of energy — but exhibited both characteristics, known as wave-particle duality.

The way light interacts with matter continues to enthral scientists and the human imagination, both for its theoretical beauty and its powerful practical application.
Whether it be how light traverses the vast spaces of the interstellar medium or the development of the laser, research into light is a vital science with important practical uses. Without these theoretical underpinnings, practically all modern technology would be impossible. No mobile phones, no global communication network, no computers, no GPS, no modern medical imaging.
One advantage of using light in communication — through optic fibres — is that packets of light energy, photons, do not easily interact with each other. This creates near distortion-free transfer of information at light speed.
However, we sometimes want light to interact. And here, things get tricky.
For instance, light is used to measure small changes in distance using instruments called interferometers. These measuring tools are now commonplace, whether it be in advanced medical imaging, for important but perhaps more prosaic tasks like performing quality control on milk, or in the form of sophisticated instruments such as LIGO, which first measured gravitational waves in 2015.

The laws of quantum mechanics set limits as to the sensitivity of such devices.
This limit is set between how sensitive a measurement can be and the average number of photons in the measuring device. For classical laser light this is different to quantum light.
Joint lead author, Dr Natasha Tomm from the University of Basel, said: “The device we built induced such strong interactions between photons that we were able to observe the difference between one photon interacting with it compared to two.
“We observed that one photon was delayed by a longer time compared to two photons. With this really strong photon-photon interaction, the two photons become entangled in the form of what is called a two-photon bound state.”
Quantum light like this has an advantage in that it can, in principle, make more sensitive measurements with better resolution using fewer photons. This can be important for applications in biological microscopy when large light intensities can damage samples and where the features to be observed are particularly small.
“By demonstrating that we can identify and manipulate photon-bound states, we have taken a vital first step towards harnessing quantum light for practical use,” Dr Mahmoodian said.
“The next steps in my research are to see how this approach can be used to generate states of light that are useful for fault-tolerant quantum computing, which is being pursued by multimillion dollar companies, such as PsiQuantum and Xanadu.”
Dr Tomm said: “This experiment is beautiful, not only because it validates a fundamental effect — stimulated emission — at its ultimate limit, but it also represents a huge technological step towards advanced applications.
“We can apply the same principles to develop more-efficient devices that give us photon bound states. This is very promising for applications in a wide range of areas: from biology to advanced manufacturing and quantum information processing.”
The research was a collaboration between the University of Basel, Leibniz University Hannover, the University of Sydney and Ruhr University Bochum.
The lead authors are Dr Natasha Tomm from the University of Basel and Dr Sahand Mahmoodian at the University of Sydney, where he is an Australian Research Council Future Fellow and Senior Lecturer.
The artificial atoms (quantum dots) were fabricated at Bochum and used in experiment performed in the Nano-Photonics Group at the University of Basel. Theoretical work on the discovery was carried out by Dr Mahmoodian at the University of Sydney and Leibniz University Hannover. More

University of Minnesota Twin Cities researchers, along with a team at the National Institute of Standards and Technology (NIST), have developed a breakthrough process for making spintronic devices that has the potential to become the new industry standard for semiconductors chips that make up computers, smartphones, and many other electronics. The new process will allow for faster, more efficient spintronics devices that can be scaled down smaller than ever before. 
The researchers’ paper is published in Advanced Functional Materials, a peer-reviewed, top-tier materials science journal.
“We believe we’ve found a material and a device that will allow the semiconducting industry to move forward with more opportunities in spintronics that weren’t there before for memory and computing applications,” said Jian-Ping Wang, senior author of the paper and professor and Robert F. Hartmann Chair in the University of Minnesota Department of Electrical and Computer Engineering. “Spintronics is incredibly important for building microelectronics with new functionalities.”
Wang said Minnesota has been leading this effort in a big way for more than 10 years with strong support by the Semiconductor Research Corporation (SRC), Defense Advanced Research Projects Agency (DARPA), and the National Science Foundation (NSF).
Wang’s team has also worked with University of Minnesota Technology Commercialization and NIST to patent this technology, along with several other patents related to this research. This discovery also opens up a new vein of research for designing and manufacturing spintronic devices for the next decade.
“This means Honeywell, Skywater, Globalfoundries, Intel, and companies like them can integrate this material into their semiconductor manufacturing processes and products,” Wang said. “That’s very exciting because engineers in the industry will be able to design even more powerful systems.”
The semiconductor industry is constantly trying to develop smaller and smaller chips that can maximize energy efficiency, computing speed, and data storage capacity in electronic devices. Spintronic devices, which leverage the spin of electrons rather than the electrical charge to store data, provide a promising and more efficient alternative to traditional transistor-based chips. These materials also have the potential to be non-volatile, meaning they require less power and can store memory and perform computing even after you remove their power source.

Spintronic materials have been successfully integrated into semiconductor chips for more than a decade now, but the industry standard spintronic material, cobalt iron boron, has reached a limit in its scalability. Currently, engineers are unable to make devices smaller than 20 nanometers without losing their ability to store data.
The University of Minnesota researchers have circumvented this problem by showing that iron palladium, an alternative material to cobalt iron boron that requires less energy and has the potential for more data storage, can be scaled down to sizes as small as five nanometers.
And, for the first time, the researchers were able to grow iron palladium on a silicon wafer using an 8-inch wafer-capable multi-chamber ultrahigh vacuum sputtering system, a one-of-a-kind piece of equipment among academic institutions across the country and only available at the University of Minnesota.
“This work is showing for the first time in the world that you can grow this material, which can be scaled down to smaller than five nanometers, on top of a semiconductor industry-compatible substrate, so-called CMOS+X strategies,” said Deyuan Lyu, first author on the paper and a Ph.D. student in the University of Minnesota Department of Electrical and Computer Engineering.
“Our team challenged ourselves to elevate a new material to manufacture spintronic devices needed for the next generation of data-hungry apps,” said Daniel Gopman, a staff scientist at NIST and one of the key contributors to the research. “It will be exciting to see how this advance drives further growth of spintronics devices within the semiconductor chip technology landscape.”
This research was funded by a $4 million, four-year grant from DARPA and in part by NIST; SMART, one of seven centers of nCORE, an SRC program; and NSF.
In addition to Wang, Gopman, and Lyu, the research team comprised University of Minnesota researchers across the College of Science and Engineering, including Department of Electrical and Computer Engineering researchers Qi Jia, William Echtenkamp, and Brandon Zink; Department of Mechanical Engineering researcher Dingbin Huang and Associate Professor Xiaojia Wang; and Characterization Facility researchers Javier García-Barriocanal, Geoffrey Rojas, and Guichuan Yu. National Institute of Standards and Technology researcher Jenae Shoup also contributed to the research. More

Security gaps exist not only in software, but also directly in hardware. Attackers might deliberately have them built in in order to attack technical applications on a large scale. Researchers at Ruhr University Bochum, Germany, and the Max Planck Institute for Security and Privacy (MPI-SP) in Bochum are exploring methods of detecting such so-called hardware Trojans. They compared construction plans for chips with electron microscope images of real chips and had an algorithm search for differences. This is how they detected deviations in 37 out of 40 cases.
The team at the CASA Cluster of Excellence (short for Cyber Security in the Age of Large-Scale Adversaries), headed by Dr. Steffen Becker, and the MPI-SP team headed by Endres Puschner, will present their findings at the IEEE Symposium on Security and Privacy, which will take place in San Francisco from 22 to 25 May 2023. The research was conducted in collaboration with Thorben Moos from the Université catholique de Louvain (Belgium) and the Federal Criminal Police Office in Germany.
The researchers released all images of the chips, the design data as well as the analysis algorithms online for free so that other research groups can use the data to conduct further studies.
Manufacturing plants as a gateway for hardware Trojans
These days, electronic chips are integrated into countless objects. They are more often than not designed by companies that don’t operate their own production facilities. The construction plans are therefore sent to highly specialised chip factories for production. “It’s conceivable that tiny changes might be inserted into the designs in the factories shortly before production that could override the security of the chips,” explains Steffen Becker and gives an example for the possible consequences: “In extreme cases, such hardware Trojans could allow an attacker to paralyse parts of the telecommunications infrastructure at the push of a button.”
Identifying differences between chips and construction plans
Becker and Puschner’s team analysed chips produced in the four modern technology sizes of 28, 40, 65 and 90 nanometres. For this purpose, they collaborated with Dr. Thorben Moos, who had designed several chips as part of his PhD research at Ruhr University Bochum and had them manufactured. Thus, the researchers had both the design files and the manufactured chips at their disposal. They obviously couldn’t modify the chips after the fact and build in hardware Trojans. And so they employed a trick: rather than manipulating the chips, Thorben Moos changed his designs retroactively in order to create minimal deviations between the construction plans and the chips. Then, the Bochum researchers tested if they could detect these changes without knowing what exactly they had to look for and where.

In the first step, the team at Ruhr University Bochum and MPI-SP had to prepare the chips using complex chemical and mechanical methods in order to take several thousand images of the lowest chip layers with a scanning electron microscope. These layers contain several hundred thousand of the so-called standard cells that carry out logical operations.
“Comparing the chip images and the construction plans turned out to be quite a challenge, because we first had to precisely superimpose the data,” says Endres Puschner. In addition, every little impurity on the chip could block the view of certain sections of the image. “On the smallest chip, which is 28 nanometres in size, a single speck of dust or a hair can obscure a whole row of standard cells,” stresses the IT security expert.
Almost all manipulations detected
The researchers used image processing methods to carefully match standard cell for standard cell and looked for deviations between the construction plans and the microscopic images of the chips. “The results give cause for cautious optimism,” as Puschner sums up the findings. For chip sizes of 90, 65 and 40 nanometres, the team successfully identified all modifications. The number of false-positive results totalled 500, i.e. standard cells were flagged as having been modified, although they were in fact untouched. “With more than 1.5 million standard cells examined, this is a very good rate,” says Puschner. It was only with the smallest chip of 28 nanometres that the researchers failed to detect three subtle changes.
Higher detection rate through clean room and optimised algorithms
A better recording quality could remedy this problem in the future. “Scanning electron microscopes do exist that are specifically designed to take chip images,” points out Becker. Moreover, using them in a clean room where contamination can be prevented would increase the detection rate even further.
“We also hope that other groups will use our data for follow-up studies,” as Steffen Becker outlines potential future developments. “Machine learning could probably improve the detection algorithm to such an extent that it would also detect the changes on the smallest chips that we missed.” More