Aurelia Butler

Researchers have discovered magnetic monopoles — isolated magnetic charges — in a material closely related to rust, a result that could be used to power greener and faster computing technologies.
Researchers led by the University of Cambridge used a technique known as diamond quantum sensing to observe swirling textures and faint magnetic signals on the surface of hematite, a type of iron oxide.
The researchers observed that magnetic monopoles in hematite emerge through the collective behaviour of many spins (the angular momentum of a particle). These monopoles glide across the swirling textures on the surface of the hematite, like tiny hockey pucks of magnetic charge. This is the first time that naturally occurring emergent monopoles have been observed experimentally.
The research has also shown the direct connection between the previously hidden swirling textures and the magnetic charges of materials like hematite, as if there is a secret code linking them together. The results, which could be useful in enabling next-generation logic and memory applications, are reported in the journal Nature Materials.
According to the equations of James Clerk Maxwell, a giant of Cambridge physics, magnetic objects, whether a fridge magnet or the Earth itself, must always exist as a pair of magnetic poles that cannot be isolated.
“The magnets we use every day have two poles: north and south,” said Professor Mete Atatüre, who led the research. “In the 19th century, it was hypothesised that monopoles could exist. But in one of his foundational equations for the study of electromagnetism, James Clerk Maxwell disagreed.”
Atatüre is Head of Cambridge’s Cavendish Laboratory, a position once held by Maxwell himself. “If monopoles did exist, and we were able to isolate them, it would be like finding a missing puzzle piece that was assumed to be lost,” he said.

About 15 years ago, scientists suggested how monopoles could exist in a magnetic material. This theoretical result relied on the extreme separation of north and south poles so that locally each pole appeared isolated in an exotic material called spin ice.
However, there is an alternative strategy to find monopoles, involving the concept of emergence. The idea of emergence is the combination of many physical entities can give rise to properties that are either more than or different to the sum of their parts.
Working with colleagues from the University of Oxford and the National University of Singapore, the Cambridge researchers used emergence to uncover monopoles spread over two-dimensional space, gliding across the swirling textures on the surface of a magnetic material.
The swirling topological textures are found in two main types of materials: ferromagnets and antiferromagnets. Of the two, antiferromagnets are more stable than ferromagnets, but they are more difficult to study, as they don’t have a strong magnetic signature.
To study the behaviour of antiferromagnets, Atatüre and his colleagues use an imaging technique known as diamond quantum magnetometry. This technique uses a single spin — the inherent angular momentum of an electron — in a diamond needle to precisely measure the magnetic field on the surface of a material, without affecting its behaviour.
For the current study, the researchers used the technique to look at hematite, an antiferromagnetic iron oxide material. To their surprise, they found hidden patterns of magnetic charges within hematite, including monopoles, dipoles and quadrupoles.

“Monopoles had been predicted theoretically, but this is the first time we’ve actually seen a two-dimensional monopole in a naturally occurring magnet,” said co-author Professor Paolo Radaelli, from the University of Oxford.
“These monopoles are a collective state of many spins that twirl around a singularity rather than a single fixed particle, so they emerge through many-body interactions. The result is a tiny, localised stable particle with diverging magnetic field coming out of it,” said co-first author Dr Hariom Jani, from the University of Oxford.
“We’ve shown how diamond quantum magnetometry could be used to unravel the mysterious behaviour of magnetism in two-dimensional quantum materials, which could open up new fields of study in this area,” said co-first author Dr Anthony Tan, from the Cavendish Laboratory. “The challenge has always been direct imaging of these textures in antiferromagnets due to their weaker magnetic pull, but now we’re able to do so, with a nice combination of diamonds and rust.”
The study not only highlights the potential of diamond quantum magnetometry but also underscores its capacity to uncover and investigate hidden magnetic phenomena in quantum materials. If controlled, these swirling textures dressed in magnetic charges could power super-fast and energy-efficient computer memory logic.
The research was supported in part by the Royal Society, the Sir Henry Royce Institute, the European Union, and the Engineering and Physical Sciences Research Council (EPSRC), part of UK Research and Innovation (UKRI). More

Seeing robots made with soft, flexible parts in action appears to lower people’s anxiety about working with them or even being replaced by them.
A Washington State University study found that watching videos of a soft robot working with a person at picking and placing tasks lowered the viewers’ safety concerns and feelings of job insecurity. This was true even when the soft robot was shown working in close proximity to the person. This finding shows soft robots hold a potential psychological advantage over rigid robots made of metal or other hard materials.
“Prior research has generally found that the closer you are to a rigid robot, the more negative your reactions are, but we didn’t find those outcomes in this study of soft robots,” said lead author Tahira Probst, a WSU psychology professor.
Currently, human and rigid robotic workers have to maintain a set distance for safety reasons, but as this study indicates, proximity to soft robots could be not only physically safer but also more psychologically accepted.
“This finding needs to be replicated, but if it holds up, that means humans could work together more closely with the soft robots,” Probst said.
The study, published in the journal IISE Transactions on Occupational Ergonomics and Human Factors, did find that faster interactions with a soft robot tended to cause more negative responses, but when the study participants had previous experience with robots, faster speed did not bother them. In fact, they preferred the faster interactions. This reinforces the finding that greater familiarity increased overall comfort with soft robots.
About half of all occupations are highly likely to involve some type of automation within the next couple decades, said Probst, particularly those related to production, transportation, extraction and agriculture.

Soft robots, which are made with flexible materials like fabric and rubber, are still relatively new technology compared to rigid robots which are already widely in use in manufacturing.
Rigid robots have many limitations including their high cost and high safety concerns — two problems soft robots can potentially solve, said study co-author Ming Luo, an assistant professor in WSU’s School of Mechanical and Materials Engineering.
“We make soft robots that are naturally safe, so we don’t have to focus a lot on expensive hardware and sensors to guarantee safety like has to be done with rigid robots,” said Luo.
As an example, Luo noted that one rigid robot used for apple picking could cost around $30,000 whereas the current research and development cost for one soft robot, encompassing all components and manufacturing, is under $5,000. Also, that cost could be substantially decreased if production were scaled up.
Luo’s team is in the process of developing soft robots for a range of functions, including fruit picking, pruning and pollinating. Soft robots also have the potential help elderly or disabled people in home or health care settings. Much more development has to be done before this can be a reality, Luo said, but his engineering lab has partnered with Probst’s psychology team to better understand human-robot interactions early in the process.
“It’s good to know how humans will react to the soft robots in advance and then incorporate that information into the design,” said Probst. “That’s why we’re working in tandem, where the psychology side is informing the technical development of these robots in their infancy.”
To further test this study’s findings, the researchers are planning to bring participants into the lab to interact directly with soft robots. In addition to collecting participants self-reported surveys, they will also measure participants’ physical stress reactions, such as heart rate and galvanic skin responses, which are changes in the skin’s electrical resistance in reaction to emotional stress. More

Recent advances allow imaging of neurons inside freely moving animals. However, to decode circuit activity, these imaged neurons must be computationally identified and tracked. This becomes particularly challenging when the brain itself moves and deforms inside an organism’s flexible body, e.g. in a worm. Until now, the scientific community has lacked the tools to address the problem.
Now, a team of scientists from EPFL and Harvard have developed a pioneering AI method to track neurons inside moving and deforming animals. The study, now published in Nature Methods, was led by Sahand Jamal Rahi at EPFL’s School of Basic Sciences.
The new method is based on a convolutional neural network (CNN), which is a type of AI that has been trained to recognize and understand patterns in images. This involves a process called “convolution,” which looks at small parts of the picture — like edges, colors, or shapes — at a time and then combines all that information together to make sense of it and to identify objects or patterns.
The problem is that to identify and track neurons during a movie of an animal’s brain, many images have to be labeled by hand because the animal appears very differently across time due to the many different body deformations. Given the diversity of the animal’s postures, generating a sufficient number of annotations manually to train a CNN can be daunting.
To address this, the researchers developed an enhanced CNN featuring ‘targeted augmentation’. The innovative technique automatically synthesizes reliable annotations for reference out of only a limited set of manual annotations. The result is that the CNN effectively learns the internal deformations of the brain and then uses them to create annotations for new postures, drastically reducing the need for manual annotation and double-checking.
The new method is versatile, being able to identify neurons whether they are represented in images as individual points or as 3D volumes. The researchers tested it on the roundworm Caenorhabditis elegans, whose 302 neurons have made it a popular model organism in neuroscience.
Using the enhanced CNN, the scientists measured activity in some of the worm’s interneurons (neurons that bridge signals between neurons). They found that they exhibit complex behaviors, for example changing their response patterns when exposed to different stimuli, such as periodic bursts of odors.
The team have made their CNN accessible, providing a user-friendly graphical user interface that integrates targeted augmentation, streamlining the process into a comprehensive pipeline, from manual annotation to final proofreading.
“By significantly reducing the manual effort required for neuron segmentation and tracking, the new method increases analysis throughput three times compared to full manual annotation,” says Sahand Jamal Rahi. “The breakthrough has the potential to accelerate research in brain imaging and deepen our understanding of neural circuits and behaviors.” More

Unmanned Underwater Vehicles (UUVs) are used around the world to conduct difficult environmental, remote, oceanic, defence and rescue missions in often unpredictable and harsh conditions.
A new study led by Flinders University and French researchers has now used a novel bio-inspired computing artificial intelligence solution to improve the potential of UUVs and other adaptive control systems to operate more reliability in rough seas and other unpredictable conditions.
This innovative approach, using the Biologically-Inspired Experience Replay (BIER) method, has been published by the Institute of Electrical and Electronics Engineers journal IEEE Access.
Unlike conventional methods, BIER aims to overcome data inefficiency and performance degradation by leveraging incomplete but valuable recent experiences, explains first author Dr Thomas Chaffre.
“The outcomes of the study demonstrated that BIER surpassed standard Experience Replay methods, achieving optimal performance twice as fast as the latter in the assumed UUV domain.
“The method showed exceptional adaptability and efficiency, exhibiting its capability to stabilize the UUV in varied and challenging conditions.”
The method incorporates two memory buffers, one focusing on recent state-action pairs and the other emphasising positive rewards.

To test the effectiveness of the proposed method, researchers conducted simulated scenarios using a robot operating system (ROS)-based UUV simulator and gradually increasing scenarios’ complexity.
These scenarios varied in target velocity values and the intensity of current disturbances.
Senior author Flinders University Associate Professor in AI and Robotics Paulo Santos says the BIER method’s success holds promise for enhancing adaptability and performance in various fields requiring dynamic, adaptive control systems.
UUVs’ capabilities in mapping, imaging and sensor controls are rapidly improving, including with Deep Reinforcement Learning (DRL), which is rapidly advancing the adaptive control responses to underwater disturbances UUVs can encounter.
However, the efficiency of these methods gets challenged when faced with unforeseen variations in real-world applications.
The complex dynamics of the underwater environment limit the observability of UUV manoeuvring tasks, making it difficult for existing DRL methods to perform optimally.
The introduction of BIER marks a significant step forward in enhancing the effectiveness of deep reinforcement learning method in general.
Its ability to efficiently navigate uncertain and dynamic environments signifies a promising advancement in the area of adaptive control systems, researchers conclude.
Acknowledgements: This work was funded by Flinders University and ENSTA Bretagne with support from the Government of South Australia (Australia), the Région Bretagne (France) and Naval Group. More

Physicists at The City College of New York have developed a technique with the potential to enhance optical data storage capacity in diamonds. This is possible by multiplexing the storage in the spectral domain. The research by Richard G. Monge and Tom Delord members of the Meriles Group in CCNY’s Division of Science, is entitled “Reversible optical data storage below the diffraction limit” and appears in the journal Nature Nanotechnology.
“It means that we can store many different images at the same place in the diamond by using a laser of a slightly different color to store different information into different atoms in the same microscopic spots,” said Delord, postdoctoral research associate at CCNY. “If this method can be applied to other materials or at room temperature, it could find its way to computing applications requiring high-capacity storage.”
The CCNY research focused on a tiny element in diamonds and similar materials, known as “color centers.” These, basically, are atomic defects that can absorb light and serve as a platform for what are termed quantum technologies.
“What we did was control the electrical charge of these color centers very precisely using a narrow-band laser and cryogenic conditions” explained Delord. “This new approach allowed us to essentially write and read tiny bits of data at a much finer level than previously possible, down to a single atom.”
Optical memory technologies have a resolution defined by what’s called the “diffraction limit,” that is, the minimum diameter that a beam can be focused to, which approximately scales as half the light beam wavelength (for example, green light would have a diffraction limit of 270 nm). “So, you cannot use a beam like this to write with resolution smaller than the diffraction limit because if you displace the beam less than that, you would impact what you already wrote. So normally, optical memories increase storage capacity by making the wavelength shorter (shifting to the blue), which is why we have “Blu-ray” technology,” said Delord.
What differentiates the CCNY optical storage approach from others is that it circumvents the diffraction limit by exploiting the slight color (wavelength) changes existing between color centers separated by less than the diffraction limit. “By tuning the beam to slightly shifted wavelengths, it can be kept at the same physical location but interact with different color centers to selectively change their charges — that is to write data with sub-diffraction resolution,” said Monge, a postdoctoral fellow at CCNY who was involved in study as a PhD student at the Graduate Center, CUNY.
Another unique aspect of this approach is that it’s reversible. “One can write, erase, and rewrite an infinite number of times,” Monge noted. “While there are some other optical storage technologies also able to do this, this is not the typical case, especially when it comes to high spatial resolution. A Blu-ray disc is again a good reference example — you can write a movie in it but you cannot erase it and write another one.” More

Wearable devices that use sensors to monitor biological signals can play an important role in health care. These devices provide valuable information that allows providers to predict, diagnose and treat a variety of conditions while improving access to care and reducing costs.
However, wearables currently require significant infrastructure — such as satellites or arrays of antennas that use cell signals — to transmit data, making many of those devices inaccessible to rural and under-resourced communities.
A group of University of Arizona researchers has set out to change that with a wearable monitoring device system that can send health data up to 15 miles — much farther than Wi-Fi or Bluetooth systems can — without any significant infrastructure. Their device, they hope, will help make digital health access more equitable.
The researchers introduced novel engineering concepts that make their system possible in an upcoming paper in the journal Proceedings of the National Academy of Sciences.
Philipp Gutruf, an assistant professor of biomedical engineering and Craig M. Berge Faculty Fellow in the College of Engineering, directed the study in the Gutruf Lab. Co-lead authors are Tucker Stuart, a UArizona biomedical engineering doctoral alumnus, and Max Farley, an undergraduate student studying biomedical engineering.
Designed for ease, function and future
The COVID-19 pandemic, and the strain it placed on the global health care system, brought attention to the need for accurate, fast and robust remote patient monitoring, Gutruf said. Non-invasive wearable devices currently use the internet to connect clinicians to patient data for aggregation and investigation.

“These internet-based communication protocols are effective and well-developed, but they require cell coverage or internet connectivity and main-line power sources,” said Gutruf, who is also a member of the UArizona BIO5 Institute. “These requirements often leave individuals in remote or resource-constrained environments underserved.”
In contrast, the system the Gutruf Lab developed uses a low power wide area network, or LPWAN, that offers 2,400 times the distance of Wi-Fi and 533 times that of Bluetooth. The new system uses LoRa, a patented type of LPWAN technology.
“The choice of LoRa helped address previous limitations associated with power and electromagnetic constraints,” Stuart said.
Alongside the implementation of this protocol, the lab developed circuitry and an antenna, which, in usual LoRa-enabled devices, is a large box that seamlessly integrates into the soft wearable. These electromagnetic, electronic and mechanical features enable it to send data to the receiver over a long distance. To make the device almost imperceptible to the wearer, the lab also enables recharge of its batteries over 2 meters of distance. The soft electronics, and the device’s ability to harvest power, are the keys to the performance of this first-of-its-kind monitoring system, Gutruf said.
The Gutruf Lab calls the soft mesh wearable biosymbiotic, meaning it is custom 3D-printed to fit the user and is so unobtrusive it almost begins to feel like part of their body. The device, worn on the low forearm, stays in place even during exercise, ensuring high-quality data collection, Gutruf said. The user wears the device at all times, and it charges without removal or effort.
“Our device allows for continuous operation over weeks due to its wireless power transfer feature for interaction-free recharging — all realized within a small package that even includes onboard computation of health metrics,” Farley said.
Gutruf, Farley and Stuart plan to further improve and extend communication distances with the implementation of LoRa wireless area network gateways that could serve hundreds of square miles and hundreds of device users, using only a small number of connection points.
The wearable device and its communication system have the potential to aid remote monitoring in underserved rural communities, ensure high-fidelity recording in war zones, and monitor health in bustling cities, said Gutruf, whose long-term goal is to make the technology available to the communities with the most need.
“This effort is not just a scientific endeavor,” he said. “It’s a step toward making digital medicine more accessible, irrespective of geographical and resource constraints.” More

Inspired by a small and slow snail, scientists have developed a robot protype that may one day scoop up microplastics from the surfaces of oceans, seas and lakes.
The robot’s design is based on the Hawaiian apple snail (Pomacea canaliculate), a common aquarium snail that uses the undulating motion of its foot to drive water surface flow and suck in floating food particles.
Currently, plastic collection devices mostly rely on drag nets or conveyor belts to gather and remove larger plastic debris from water, but they lack the fine scale required for retrieving microplastics. These tiny particles of plastic can be ingested and end up in the tissues of marine animals, thereby entering the food chain where they become a health issue and potentially carcinogenic to humans.
“We were inspired by how this snail collects food particles at the [water and air] interface to engineer a device that could possibly collect microplastics in the ocean or at a water body’s surface, ” said Sunghwan “Sunny” Jung, professor in the department of biological and environmental engineering at Cornell University. Jung is senior author of a study, “Optimal free-surface pumping by an undulating carpet,” which published in Nature Communications.
The prototype, modified from an existing design, would need to be scaled up to be practical in a real-world setting. The researchers used a 3D printer to make a flexible carpet-like sheet capable of undulating. A helical structure on the underside of the sheet rotates like a corkscrew to cause the carpet to undulate and create a travelling wave on the water.
Analyzing the motion of the fluid was key to this research. “We needed to understand the fluid flow to characterize the pumping behavior,” Jung said. The fluid-pumping system based on the snail’s technique is open to the air. The researchers calculated that a similar closed system, where the pump is enclosed and uses a tube to suck in water and particles, would require high energy inputs to operate. On the other hand, the snail-like open system is far more efficient. For example, the prototype, though small, runs on only 5 volts of electricity while still effectively sucking in water, Jung said.
Due to the weight of a battery and motor, the researchers may need to attach a floatation device to the robot to keep it from sinking, Jung said.
Anupam Pandey, a former postdoctoral researcher in Jung’s lab, currently an assistant professor of mechanical engineering at Syracuse University, is the paper’s first author.
The study was funded by the National Science Foundation. More

Graphene, that is extremely thin carbon, is considered a true miracle material. An international research team has now added another facet to its diverse properties with experiments at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR): The experts, led by the University of Duisburg-Essen (UDE), fired short terahertz pulses at micrometer-sized discs of graphene, which briefly turned these minuscule objects into surprisingly strong magnets. This discovery may prove useful for developing future magnetic switches and storage devices.
Graphene consists of an ultra-thin sheet of just one layer of carbon atoms. But the material, which was only discovered as recently as 2004, displays remarkable properties. Among them is its ability to conduct electricity extremely well, and that is precisely what international researchers from Germany, Poland, India, and the USA took advantage of.
They applied thousands of tiny, micrometer-sized graphene discs onto a small chip using established semiconductor techniques. This chip was then exposed to a particular type of radiation situated between the microwave and infrared range: short terahertz pulses.
To achieve the best possible conditions, the working group, led by the UDE, used a particular light source for the experiment: The FELBE free-electron laser at the HZDR can generate extremely intense terahertz pulses. The astonishing result: “The tiny graphene disks briefly turned into electromagnets,” reports HZDR physicist Dr. Stephan Winnerl.
“We were able to generate magnetic fields in the range of 0.5 Tesla, which is roughly ten thousand times the Earth’s magnetic field.” These were short magnetic pulses, only about ten picoseconds or one-hundredth of a billionth of a second long.
Radiation pulses stir electrons
The prerequisite for success: The researchers had to polarize the terahertz flashes in a specific way. Specialized optics changed the direction of oscillation of the radiation so that it moved, figuratively speaking, helically through space.

When these circularly polarized flashes hit the micrometer-sized graphene discs, the decisive effect occurred: Stimulated by the radiation, the free electrons in the discs began to circle — just like water in a bucket stirred with a wooden spoon. And because, according to the basic laws of physics, a circulating current always generates a magnetic field, the graphene disks mutated into tiny electromagnets.
“The idea is actually quite simple,” says Martin Mittendorff, professor at the University of Duisburg-Essen. “In hindsight, we are surprised nobody had done it before.” Equally astonishing is the efficiency of the process: Compared to experiments irradiating nanoparticles of gold with light, the experiment at the HZDR was a million times more efficient — an impressive increase. The new phenomenon could initially be used for scientific experiments in which material samples are exposed to short but strong magnetic pulses to investigate certain material properties in more detail.
The advantage: “With our method, the magnetic field does not reverse polarity, as is the case with many other methods,” explains Winnerl. “It, therefore, remains unipolar.” In other words, during the ten picoseconds that the magnetic pulse from the graphene disks lasts, the north pole remains a north pole and the south pole a south pole — a potential advantage for certain series of experiments.
The dream of magnetic electronics
In the long run, those minuscule magnets might even be useful for certain future technologies: As ultra-short radiation flashes generate them, the graphene discs could carry out extremely fast and precise magnetic switching operations. This would be interesting for magnetic storage technology, for example, but also for so-called spintronics — a form of magnetic electronics.
Here, instead of electrical charges flowing in a processor, weak magnetic fields in the form of electron spins are passed on like tiny batons. This may, so it is hoped, significantly speed up the switching processes once again. Graphene disks could conceivably be used as switchable electromagnets to control future spintronic chips.
However, experts would have to invent very small, highly miniaturized terahertz sources for this purpose — certainly still a long way to go. “You cannot use a full-blown free-electron laser for this, like the one we used in our experiment,” comments Stephan Winnerl. “Nevertheless, radiation sources fitting on a laboratory table should be sufficient for future scientific experiments.” Such significantly more compact terahertz sources can already be found in some research facilities. More