Effective new catalyst brings hope for cleaner energy, wastewater treatment, and green chemistry

Hokkaido University

 

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Scanning electron micrograph of the catalyst, NiOOH-Ni, developed in this study. (Hanwen Liu, et al. Advanced Energy Materials. August 7, 2024)

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Credit: Hanwen Liu, et al. Advanced Energy Materials. August 7, 2024

A catalyst that significantly enhances ammonia conversion could improve wastewater treatment, green chemical and hydrogen production.

A team of scientists have developed an effective catalyst with a remarkable ability to enhance the efficiency of ammonia conversion. Published in Advanced Energy Materials, the study reveals the catalyst's potential to significantly advance wastewater treatment, green nitrite and nitrate, as well as hydrogen production.

Catalysts are substances that speed up chemical reactions by providing a more efficient route for a reaction to occur and making it easier to start and finish. Since catalysts are neither consumed nor altered in the reaction, they can be used repeatedly, and they are essential in a variety of industrial, environmental, and biochemical processes.

The team, which included researchers from Japan’s Hokkaido University, Australia’s University of Technology Sydney and elsewhere, developed the catalyst, called NiOOH-Ni, by combining nickel (Ni) with nickel oxyhydroxide.

Ammonia can cause severe environmental problems, such as excessive algal growth in water bodies, which depletes oxygen and harms aquatic life. At high concentrations, ammonia can harm humans and wildlife. Effective management and conversion of ammonia are thus critical, but its corrosive nature makes it difficult to handle.

The researchers developed NiOOH-Ni using an electrochemical process. Nickel foam, a porous material, was treated with an electrical current while immersed in a chemical solution. This treatment resulted in the formation of nickel oxyhydroxide particles on the foam’s surface. Despite their irregular and non-crystalline structure, these nickel-oxygen particles significantly enhance ammonia conversion efficiency. The catalyst’s design allows it to operate effectively at lower voltages and higher currents than traditional catalysts.

“NiOOH-Ni works better than Ni foam, and the reaction pathway depends on the amount of electricity (voltage) used,” explains Professor Zhenguo Huang from the University of Technology Sydney, who led the study. “At lower voltages, NiOOH-Ni produces nitrite, while at higher voltages, it generates nitrate.”

This means the catalyst can be used in different ways depending on what is needed. For example, it can be used to clean wastewater by converting ammonia into less harmful substances. But in another process, it can also be used to produce hydrogen gas, a clean fuel. This flexibility makes NiOOH-Ni valuable for various applications.

"NiOOH-Ni is impressively durable and stable, and it works well even after being used multiple times," says Associate Professor Andrey Lyalin from Hokkaido University, who was involved in the study. "This makes it a great alternative to traditional, more expensive catalysts like platinum, which aren’t as effective at converting ammonia."

The catalyst’s long-term reliability makes it suitable for large-scale industrial use, potentially transforming how industries handle wastewater and produce clean energy.

The reaction cell for simultaneous hydrogen production and ammonia oxidation. (Hanwen Liu, et al. Advanced Energy Materials. August 7, 2024)

Electrolysis of ammonia aqueous solution produces nitrite and nitrate on the NiOOH-Ni anode, and green hydrogen on the Ni2P-Ni cathode. This presents advantages over the currently used thermal ammonia cracking due to the simultaneous formation of hydrogen as an energy carrier and nitrite and nitrate as valuable chemicals under ambient conditions. (Hanwen Liu, et al. Advanced Energy Materials. August 7, 2024)

Credit

Hanwen Liu, et al. Advanced Energy Materials. August 7, 2024

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Journal

Advanced Energy Materials

DOI

10.1002/aenm.202401675 

Method of Research

Experimental study

Subject of Research

Not applicable

Article Title

Electrocatalytic Ammonia Oxidation to Nitrite and Nitrate with NiOOH-Ni

Article Publication Date

7-Aug-2024

The olfactory performance of family dogs was tested by Hungarian ethologists

Dogs’ olfaction have been used for various tasks from hunting to disease identification, sparking scientific interest in the factors that truly influence their olfactory performance

Eötvös Loránd University

 

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A new comprehensive study by the ethologists of ELTE Eötvös Loránd University provides valuable insights into the olfactory abilities of dogs, revealing whether certain environmental and biological factors do indeed impact their performance as previously thought. The study was published in Sceintific Reports.

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Credit: Photo: Attila Salamon / Department of Ethology, ELTE Eötvös Loránd University

A new comprehensive study by the ethologists of ELTE Eötvös Loránd University provides valuable insights into the olfactory abilities of dogs, revealing whether certain environmental and biological factors do indeed impact their performance as previously thought. The study was published in Scientific Reports.

Dogs’ olfaction have been used for various tasks from hunting to disease identification, sparking scientific interest in the factors that truly influence their olfactory performance. The first author, Attila Salamon from the ELTE NAP Canine Brain Research Group, said that „such tasks require specific training, but the outcomes of the tests conducted with these specially trained dogs cannot be generalized to the entire species.”

A team of researchers from the Department of Ethology, ELTE Eötvös Loránd University, Budapest, undertook the challenge of examining the olfactory performance of more than four hundred untrained family dogs of various breeds. This study aimed to provide a more comprehensive

understanding of dogs' scent detection capabilities and determine whether specific environmental and demographic factors influence their performance in an olfactory task.

The study used the Natural Detection Task – developed by the team and already successfully applied even in the case of wolves – a  simple search task, in which the dogs had to find a hidden dog treat in a line of pots. No training was necessary, as the test leveraged the dogs' natural motivation for food. The task featured three difficulty levels; the first level acted as a pre-test to ensure the dogs understood the task, were motivated, and did not rely on alternative problem-solving methods. Dogs successfully completing the third level were considered to be the best.

During the test an experimenter – unaware of the location of the hidden food – was observing whether the dog spontaneously indicated a pot (e.g., licking the pot, placing the paw on the pot, poking or pushing the pot with the nose).

Contrary to common assumptions, temperature (ranging from 0 to 25 °C) and humidity (between 18 to 90%) were found to have no significant effect on the dogs' ability to detect the target scent. However, the test location was an important factor; dogs tested indoors outperformed those tested outdoors, indicating that distracting stimuli in outdoor environments may significantly impact performance in olfactory tasks.

Considering the demographic factors,

there was no difference in olfactory performance based on the sex or neutering status of the dogs.

However, the study revealed that 2-3 year old dogs exhibited somewhat superior olfactory performance compared to dogs younger than 2 years and older than 6 years.

The researchers retested a subsample of the dogs to assess the reliability of the test and did not find a significant learning effect between the two test occasions, that is, the dogs did not perform better during the second test. This confirms the suitability of this method for testing the olfactory performance of untrained family dogs.

"By revealing the factors that really influence the effectiveness, our study can provide answers to important questions that have long concerned professionals using the olfactory abilities of dogs. Focusing on a large and diverse sample of untrained dogs, we can better generalize these findings to the broader canine population" – concluded Márta Gácsi, the lead researcher.

Dogs’ olfaction have been used for various tasks from hunting to disease identification, sparking scientific interest in the factors that truly influence their olfactory performance. The first author, Attila Salamon from the ELTE NAP Canine Brain Research Group, said that „such tasks require specific training, but the outcomes of the tests conducted with these specially trained dogs cannot be generalized to the entire species.”

Credit

Photo: Attila Salamon / Department of Ethology, ELTE Eötvös Loránd University

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Journal

Scientific Reports

DOI

10.1038/s41598-024-62957-5 

Article Title

Success in the Natural Detection Task is influenced by only a few factors generally believed to affect dogs’ olfactory performance

Prioritize well-being over growth: new paradigm needed for climate-friendly lifestyles

Research Institute for Sustainability (RIFS) – Helmholtz Centre Potsdam

Ensuring the well-being of citizens while reducing resource consumption has proved to be a massive challenge. Policymakers in the European Union are keen to identify new approaches to provisioning that will safeguard the well-being of citizens without incurring excessive environmental burdens. A study conducted in five EU countries concludes that rather than economic growth, the satisfaction of citizens’ needs should take centre-stage in efforts to rethink and redesign provisioning systems.

“In order to deliver on the goals of the Paris Climate Agreement we must change the current unsustainable patterns of production and consumption across the four central provisioning systems of food, mobility, housing, and leisure. Our research sought to identify the key structural barriers to change. To achieve this, we conducted interviews with experts in five EU countries - Germany, Latvia, Sweden, Spain and Hungary - and held discussions in Stakeholder Think Labs with local representatives from politics, civil society, media and think tanks,” explains lead author Halliki Kreinin (Research Institute for Sustainability - Helmholtz Centre Potsdam, RIFS). This research was carried out through the EU 1.5° Lifestyles project consortium, which is coordinated by RIFS.

The interviewees identified the economic growth paradigm as the most impactful barrier to the transformation of provisioning systems. In their opinion, it is so powerful that actors in all areas of society have adopted it indiscriminately as a goal for action. A needs-oriented approach, focused on ensuring the well-being of all, offers an alternative. Pivoting to this narrative would also help to build acceptance for the necessary downsizing or phase-out of some harmful industries and technologies.

Holistic approach to sustainability policy needed

Establishing individual and collective well-being as a guiding principle, offers the opportunity to pursue more consistent sustainability policies, the interviewees stated. Many people favour measures such as bans, limits and taxes where necessary. “Restricting or strongly disincentivising the purchase and use of extremely polluting goods and services such as private jets, private space travel or SUVs would be one important step. However, individual measures alone will not suffice; rather, interlinking policies and measures are needed. At the moment, climate and economic policies are frequently at odds with each other,” says RIFS director Doris Fuchs, who co-authored the study.

In order to implement a coherent sustainability policy, governments would have to curb the influence of powerful interest groups such as the fossil fuel industry. Other important enablers for change include incentivising investment in sustainable technologies and products and incorporating environmental costs in pricing, for example by lowering taxes on labour and raising those on emissions / energy consumption.

Social inequality hinders change

The interviewees also mentioned various soft factors such as strengthening alternative narratives and the adoption of alternative indicators of quality of life. The problem of inequality came up repeatedly in the Stakeholder Think Labs. Poorer population groups are most affected by climate change, but also lack the resources to bring about change. Future policymaking must facilitate their participation. Issues relating to sustainability should also be included in curricula and school education to promote change.

Interviewees across all five countries emphasised that comprehensive structural change is necessary, explains Halliki Kreinin: “We cannot leave the fight against climate change to individual citizens. Instead, we must fundamentally change our provisioning systems. Currently, these systems are failing to meet the needs of populations and are operating at levels of resource consumption that are too high deliver.” Developing sustainable provisioning systems that can satisfy needs and deliver on the Paris Climate Goals will require a comprehensive transformation with concerted strategic measures at the system level.

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Journal

Sustainability Science Practice and Policy

DOI

10.1080/15487733.2024.2372120 

Method of Research

Experimental study

Subject of Research

Not applicable

Article Title

Transforming provisioning systems to enable 1.5° lifestyles in Europe? Expert and stakeholder views on overcoming structural barriers

 

European X-ray laser explores a poorly understood state of matter

The Henryk Niewodniczanski Institute of Nuclear Physics Polish Academy of Sciences

 

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Warm dense matter occurs inside Jupiter-type giant planets (where it surrounds the rocky core as a metallic liquid at a temperature of many thousands of kelvin) and in the interiors of small stars – brown dwarfs.

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Credit: Source: IFJ PAN / NASA

The properties of warm dense matter have until recently been little known. Now, thanks to the use of X-ray lasers, physicists are gaining more and more information about this important but still mysterious state of matter. The first comprehensive observations of ionisation processes in warm dense matter, carried out at the European X-ray Free-Electron Laser (European XFEL), have just been presented in one of the most prestigious physics journals.

State of matter with a temperature of a few thousand degrees and a high density, close to that of a solid, can be found, among others, in the interiors of brown dwarfs or gaseous planets. Although common in the Universe, it is very difficult to be produced and analysed in the laboratory. A new era in experimental research of this so-called warm dense matter (WDM) state began just a dozen years ago, when physicists launched the first free-electron X-ray lasers. At the forefront of this type of device is the nearly 3.5 km-long European XFEL laser. A series of experiments recently carried out there made it possible to observe for the first time how quickly a metal transforms into the exotic state of ionised WDM to become transparent (non-absorbing) to X-rays at the end of the process. The achievement of the international team of scientists – including those from the Institute of Nuclear Physics of the Polish Academy of Sciences (IFJ PAN) in Cracow – is discussed in a paper published in the journal Nature Physics.

X-Ray Free-Electron Lasers (XFELs) are used to generate high-intensity X-ray pulses lasting single femtoseconds, i.e. millionths of a billionth of a second. These can be used to study the structure of matter at atomic length scales and to track phenomena on extremely short time scales. One of only a dozen such devices in the world is the European XFEL in Hamburg, built in cooperation with the DESY research centre.

“In our experiment at the European XFEL, we illuminated copper samples with X-ray pulses lasting 15 femtoseconds, using different, gradually increasing intensities”, Prof. Beata Ziaja-Motyka (IFJ PAN, DESY) introduces the experiment. The first author of the paper in question, Dr. Laurent Mercadier from the European XFEL, adds some physical details: “When a single X-ray laser pulse reached the material, it caused strong ionisation. The electrons released in the process were characterised by high temperatures. Under these extreme conditions, the copper was transformed into a state of warm dense matter. We meticulously recorded how much radiation passed through the matter and from this inferred the ionisation changes in the observed system.”

Simulations carried out using the BOLTZMANN SOLVER software, developed since 2004 at DESY by Prof. Ziaja-Motyka, were particularly helpful in interpreting the measurement results. This tool was used to simulate changes in the electronic occupancy of individual energy levels in WDM depending on the intensity of the incident laser radiation.

By confronting experimental data with simulations, it was established that when the X-ray intensity becomes sufficiently high, atoms of WDM become strongly ionised. As a result of this phenomenon, new energy levels appear which can be occupied by excited electrons – making WDM opaque for photons resonant with transitions to these new energy levels. These states had already been observed previously with optical lasers, however, the lasers’ energy limitations did not allow them to be studied in more detail. Now, thanks to the European X-ray laser XFEL, it is possible to characterise them accurately also in response to various intensities of X-ray pulses. In accordance with theoretical predictions for X-ray absorption spectra, prepared by Dr. Joshua Kas (University of Washington, USA) and Dr. Andrei Benediktovitch (DESY, Hamburg), it was further observed that with increasing the laser intensity the warm dense matter becomes first opaque and then – at highest intensities – transparent to the laser pulse.

“The appearance of ‘transparency’ – i.e. lack of absorption – in WDM is a consequence of the high ionisation of WDM atoms occurring at sufficiently high X-ray pulse intensities. The energy of the X-ray photons available in the experiment then becomes too small to excite further electrons. As a result, these photons cannot be absorbed by the warm dense matter at all,” explains Prof. Ziaja-Motyka.

Knowledge of the properties of warm dense matter and the processes taking place within it is not only of astrophysical, but also of practical, engineering importance. Matter in this state plays an important role in certain types of controlled nuclear fusion (ICF – Inertial Confinement Fusion), and also appears during the ablation of metallic heat shields of spacecraft returning from orbit to Earth.

The team of physicists at the European X-ray XFEL laser, led by Prof. Nina Rohringer (DESY, Universität Hamburg), intends to continue research into the electron and ionisation processes occurring in WDM and their dynamics. On the Polish side, the work is co-financed by the Institute of Nuclear Physics of the Polish Academy of Sciences.

 

The Henryk Niewodniczański Institute of Nuclear Physics (IFJ PAN) is currently one of the largest research institutes of the Polish Academy of Sciences. A wide range of research carried out at IFJ PAN covers basic and applied studies, from particle physics and astrophysics, through hadron physics, high-, medium-, and low-energy nuclear physics, condensed matter physics (including materials engineering), to various applications of nuclear physics in interdisciplinary research, covering medical physics, dosimetry, radiation and environmental biology, environmental protection, and other related disciplines. The average yearly publication output of IFJ PAN includes over 600 scientific papers in high-impact international journals. Each year the Institute hosts about 20 international and national scientific conferences. One of the most important facilities of the Institute is the Cyclotron Centre Bronowice (CCB), which is an infrastructure unique in Central Europe, serving as a clinical and research centre in the field of medical and nuclear physics. In addition, IFJ PAN runs four accredited research and measurement laboratories. IFJ PAN is a member of the Marian Smoluchowski Kraków Research Consortium: “Matter-Energy-Future”, which in the years 2012-2017 enjoyed the status of the Leading National Research Centre (KNOW) in physics. In 2017, the European Commission granted the Institute the HR Excellence in Research award. As a result of the categorization of the Ministry of Education and Science, the Institute has been classified into the A+ category (the highest scientific category in Poland) in the field of physical sciences.

SCIENTIFIC PUBLICATIONS:

“Transient Absorption of Warm Dense Matter Created by an X-Ray Free-Electron Laser”

Mercadier, A. Benediktovitch, S. Krusic, J. J. Kas, J. Schlappa, M. Agaker, R. Carley, G. Fazio, N. Gerasimova, Y. Y. Kim, L. Le Guyader, G. Mercurio, S. Parchenko, J. J. Rehr, J.-E. Rubensson, S. Serkez, M. Stransky, M. Teichmann, Z. Yin, M. Zitnik, A. Scherz, B. Ziaja-Motyka, N. Rohringer

Nature Physics 2024

DOI: 10.1038/s41567-024-02587-w

 

LINKS:

http://www.ifj.edu.pl/

The website of the Institute of Nuclear Physics, Polish Academy of Sciences.

http://press.ifj.edu.pl/

Press releases of the Institute of Nuclear Physics, Polish Academy of Sciences.

 

IMAGES:

IFJ240807b_fot01s.jpg

HR: http://press.ifj.edu.pl/news/2024/08/07/IFJ240807b_fot01.jpg

Warm dense matter occurs inside Jupiter-type giant planets (where it surrounds the rocky core as a metallic liquid at a temperature of many thousands of kelvin) and in the interiors of small stars – brown dwarfs. (Source: IFJ PAN / NASA)

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Journal

Nature Physics

DOI

10.1038/s41567-024-02587-w 

Article Title

Transient Absorption of Warm Dense Matter Created by an X-Ray Free-Electron Laser

 

Cleveland Clinic study adds to increasing evidence that sugar substitute erythritol raises cardiovascular risk

Erythritol is a common artificial sweetener found in baked goods, beverages, gum and candy

Peer-Reviewed Publication

Cleveland Clinic

 

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New Cleveland Clinic research, led by Dr. Stanley Hazen, shows that consuming foods with erythritol, a popular artificial sweetener, increases risk of cardiovascular events.

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Credit: Cleveland Clinic

August 8, 2024, Cleveland: New Cleveland Clinic research shows that consuming foods with erythritol, a popular artificial sweetener, increases risk of cardiovascular events such as heart attack and stroke. The findings, from a new intervention study in healthy volunteers, show erythritol made platelets (a type of blood cell) more active, which can raise the risk of blood clots. Sugar (glucose) did not have this effect.

 

Published in Arteriosclerosis, Thrombosis and Vascular Biology, the research adds to increasing evidence that erythritol may not be as safe as currently classified by food regulatory agencies and should be reevaluated as an ingredient. The study was conducted by a team of Cleveland Clinic researchers as part of a series of investigations on the physiological effects of common sugar substitutes.

 

“Many professional societies and clinicians routinely recommend that people at high cardiovascular risk – those with obesity, diabetes or metabolic syndrome – consume foods that contain sugar substitutes rather than sugar,” said senior and corresponding author Stanley Hazen, M.D., Ph.D., chair of Cardiovascular and Metabolic Sciences in Cleveland Clinic’s Lerner Research Institute and co-section head of Preventive Cardiology. “These findings underscore the importance of further long-term clinical studies to assess the cardiovascular safety of erythritol and other sugar substitutes.”

 

Erythritol and other artificial sweeteners are common replacements for table sugar in low-calorie, low-carbohydrate and “keto” products. Erythritol is about 70% as sweet as sugar and is produced through fermenting corn. After ingestion, erythritol is poorly metabolized by the body. Instead, it goes into the bloodstream and leaves the body mainly through urine. The human body creates low amounts of erythritol naturally, so any additional consumption can accumulate.

 

Erythritol is classified by the U.S. Food and Drug Administration and the European Food Safety Authority as a GRAS (“generally recognized as safe”) ingredient, allowing its use without restriction in food products. This is primarily because it is a sugar alcohol found naturally in fruits and vegetables and a byproduct of glucose metabolism in human tissue, although in small quantities.
 

However, recent studies by Dr. Hazen’s group, have found evidence that erythritol in typically consumed amounts may increase cardiovascular risk.

 

The current research builds on the team’s previous study, published last year in Nature Medicine, which revealed that cardiac patients with high erythritol levels were twice as likely to experience a major cardiac event in the following three years compared to those with low levels. The study also discovered that adding erythritol to patients’ blood or platelets increased clot formation. These findings were confirmed by pre-clinical studies.

 

The new human intervention study was designed to more directly observe the effects on platelets following erythritol ingestion at a dose typically contained in a “sugarless” soda or muffin. In 20 healthy volunteers, researchers found that the average erythritol level after eating increased over 1,000 times in the group that consumed erythritol compared to their initial levels. Results also revealed participants showed a significant increase in blood clot formation after consuming erythritol, but no change was observed after consuming glucose.

 

“This research raises some concerns that a standard serving of an erythritol-sweetened food or beverage may acutely stimulate a direct clot-forming effect,” said study co-author W. H. Wilson Tang, M.D., research director for Heart Failure and Cardiac Transplantation Medicine at Cleveland Clinic. “Erythritol and other sugar alcohols that are commonly used as sugar substitutes should be evaluated for potential long-term health effects especially when such effects are not seen with glucose itself.”

He adds that the results of this study are especially notable because they come on the heels of another recent study by this research group showing that xylitol, another common artificial sweetener, produced similar increases in plasma levels and affected platelet aggregation in healthy volunteers the same way. Like erythritol, studies with xylitol also included large-scale observation studies demonstrating that high xylitol levels are associated with increased risk of heart attack, stroke or death over the following three years.

 

The authors note that further clinical studies assessing the long-term cardiovascular safety of erythritol are warranted.

 

“I feel that choosing sugar-sweetened treats occasionally and in small amounts would be preferable to consuming drinks and foods sweetened with these sugar alcohols, especially for people at elevated risk of thrombosis such as those with heart disease, diabetes or metabolic syndrome,” Dr. Hazen advises. “Cardiovascular disease builds over time, and heart disease is the leading cause of death globally. We need to make sure the foods we eat aren’t hidden contributors.”

 

The research is part of Dr. Hazen’s ongoing investigation into factors that contribute to residual cardiovascular risk. His team follows patients over time and finds chemical signatures in blood that can predict the future development of heart and metabolic disease. He has made pioneering discoveries in atherosclerosis and inflammatory disease research, including the seminal discovery linking gut microbial pathways to cardiovascular disease and metabolic diseases.  

 

Dr. Hazen also directs Cleveland Clinic’s Center for Microbiome and Human Health and holds the Jan Bleeksma Chair in Vascular Cell Biology and Atherosclerosis.  

 

The study was supported in part by National Institutes of Health and the Office of Dietary Supplements.

 

Disclosures: Dr. Hazen is named as co-inventor on pending and issued patents held by Cleveland Clinic in relation to cardiovascular diagnostics and therapeutics.  

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Journal

Arteriosclerosis Thrombosis and Vascular Biology

DOI

10.1161/ATVBAHA.124.321019 

Article Title

Ingestion of the Non-Nutritive Sweetener Erythritol, but Not Glucose, Enhances Platelet Reactivity and Thrombosis Potential in Healthy Volunteers

Article Publication Date

8-Aug-2024

 

HKUST develops groundbreaking artificial compound eye to revolutionize robotic vision at lower cost but higher sensitivity

Enhancing autonomous driving and emergency rescue

Hong Kong University of Science and Technology

 

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The research paper was featured as the cover article in Science Robotics (Volume 9, Issue 90) in May 2024. The cover shows a fusion of an image composite of a robber fly’s eye on the left and an illustration of the pinhole compound eye on the right.

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Credit: HKUST

A research team at the School of Engineering of the Hong Kong University of Science and Technology (HKUST) has recently developed a novel artificial compound eye system that is not only more cost-effective, but demonstrates a sensitivity at least twice that of existing market products in small areas. The system promises to revolutionize robotic vision, enhance robots' abilities in navigation, perception and decision-making, while promoting commercial application and further development in human-robot collaboration. 

Mimicking the visual capabilities of compound eyes, this innovative system can be applied in a wide range of scenarios, such as installing on drones to improve their accuracy and efficiency in tasks like irrigation or emergency rescue in disaster sites. With its high sensitivity, the system can also enable closer collaboration among robots and other connected devices. In the long term, the compound eye system will enhance autonomous driving safety and accelerate the adoption of intelligent transport systems, fostering the development of smart cities. 

Developed by the team led by Prof. FAN Zhiyong, Chair Professor at HKUST’s Department of Electronic & Computer Engineering and Department of Chemical & Biological Engineering, this groundbreaking technology represents a significant leap forward in the field of biomimetic vision systems. 

Traditionally, roboticists have mainly focused on replicating the visual capabilities of insects, which offer a wide field of view and advanced motion-tracking capabilities. However, integrating compound eye systems into autonomous platforms like robots or drones has been challenging as these systems often suffer from issues related to complexity and stability during deformation, geometry constraints, as well as potential mismatches between optical and detector components.

To address these challenges, Prof. Fan’s team developed a pinhole compound vision system by adopting new materials and structures. This system features several key characteristics, including an inherent hemispherical perovskite nanowire array imager with high pixel density to enlarge the imaging field; and a 3D-printed lens-free pinhole array with a customizable layout to regulate incident light and eliminate the blind area between neighboring ommatidia (individual units within an insect’s compound eye). Owing to its good angular selectivity, a wide field of view, wide spectrum response in monocular and binocular configurations, as well as its dynamic motion tracking capability, the pinhole compound eye not only can accurately locate targets but can also track a moving quadruped robot after incorporated onto a drone.

Prof. Fan said, “This compound eye design is simple, light and cheap. Although it won’t fully replace traditional cameras, it could be a huge boost in certain robotics applications, such as in a swarm of drones flying in close formation. By further miniaturizing the device size and increasing the number of ommatidia, imaging resolution, and response speed, this type of device can find broad applications in optoelectronics and robotics.”

As a renowned researcher in biomimetic optoelectronics, Prof. Fan is keen on combining practical approach with daring imaginations to drive innovative research. This unique compound eye work marks another breakthrough in the field of vision and robotic systems following his development of the world’s first spherical artificial eye with 3D retina in 2020. 

The research work was published and featured as a cover article in top-tier international journal Science Robotics. Dr. ZHOU Yu (postdoc), Dr. SUN Zhibo (postdoc), and DING Yucheng (PhD student) are the co-first authors while Prof. Fan is the corresponding author. 

Research Team 

(From left) Prof. Fan Zhiyong and co-first authors Dr. Zhou Yu (postdoc), Dr. Sun Zhibo (postdoc), and Ding Yucheng (PhD student).

Schematic illustration and images of the pinhole compound eye camera and integrated components

Imaging capability of the pinhole compound eye camera.

ng and on-drone motion tracking of the pinhole compound eye camera system.

An ultra-wide field-of-view pi [VIDEO] | 

An ultra-wide field-of-view pinhole compound eye using hemispherical nanowire array for robot vision 

Journal

Science Robotics

DOI

10.1126/scirobotics.adi8666 

Method of Research

Experimental study

Subject of Research

Not applicable

Article Title

An ultrawide field-of-view pinhole compound eye using hemispherical nanowire array for robot vision

 

New solution for green hydrogen production

Scientists at Paderborn University are researching carbon materials for photocatalysis

Universität Paderborn

Coal, gas, oil: the use of fossil fuels is declining. Clean energy gained from renewable sources is gradually supplanting its polluting competition. For an energy source to be able to be widely used, it must be affordable and, above all, available. In recent years, hydrogen has proven to be particularly suitable for various applications. However, its production currently usually requires fossil fuels. To change this, scientists at Paderborn University are working on a new research project to examine how hydrogen could be obtained from solar energy using specific carbon materials – in other words, thoroughly green. This project, entitled ‘C2-SPORT’ (standing for ‘Carbon Composites as Direct Z-Scheme Photocatalysts for Overall Water Splitting’), is receiving around 20,000 euros of funding as part of Paderborn University’s internal Wissenschaftskolleg. 

‘Using sunlight for water splitting in hydrogen and oxygen brings us a step closer to the ideal concept of a profitable, environmentally friendly energy source’, explains Junior Professor Maria Nieves López Salas of the Department of Chemistry at Paderborn University, who is heading up the project with Dr. Ying Pan, also from the Department of Chemistry. Their concept is based on what is known as the ‘direct Z-scheme’, a method inspired by natural photosynthesis. In simple terms, this involves combining two types of semiconductors. What makes this process special is that it incorporates the strengths of both types, achieving a previously unheard-of level of efficiency in water splitting. López Salas explains: ‘Semiconductor-based photocatalytic water splitting using solar energy to produce hydrogen and oxygen from water has proven to be a promising solution for tackling energy and environmental issues’. However, there are still obstacles to overcome: for example, splitting water entirely into hydrogen and oxygen using just one catalyst material is extremely difficult. ‘In photocatalytic reactions, light absorption, charge carrier separation and the surface reactions of catalysts work together to create hydrogen from sunlight. To ensure high efficiency, these catalysts must be able to absorb light and separate charges efficiently, among other things’, López Salas adds. The currently available semiconductors that consist of a single material struggle to meet these requirements.

Semiconductors containing carbon could be an interesting option for Z-scheme photocatalyst systems. This is partly because they offer good photocatalytic activity and are lighter than other materials such as titanium dioxide. They are also cheaper, reliable, and widely available on this planet. Suitable strategies that need to be researched could make them excellent candidates for hydrogen production. Pan notes: ‘Understanding this will have a significant impact on the search for technologies to convert solar energy into hydrogen energy. It could form the basis for extremely efficient catalysts and represent a major step towards new artificial photosynthesis devices.’

This project has been funded under the Paderborner Wissenschaftskolleg since April of this year. The aim is to create new research impetus at Paderborn University via interdisciplinary research projects and international collaborations. The call for tender is open to applicants from all fields and is aimed at postdoctoral researchers. The Wissenschaftskolleg offers an opportunity to work together with colleagues from foreign universities or research institutions on internationally oriented research projects. Visiting researchers from universities in Australia and China are also involved in the ‘C2-Sport’ project.