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index.feed.received.today — 3 avril 20256.5 📰 Sciences English

Operating system for quantum networks is a first

3 avril 2025 à 15:08

Researchers in the Netherlands, Austria, and France have created what they describe as the first operating system for networking quantum computers. Called QNodeOS, the system was developed by a team led by Stephanie Wehner at Delft University of Technology. The system has been tested using several different types of quantum processor and it could help boost the accessibility of quantum computing for people without an expert knowledge of the field.

In the 1960s, the development of early operating systems such as OS/360 and UNIX  represented a major leap forward in computing. By providing a level of abstraction in its user interface, an operating system enables users to program and run applications, without having to worry about how to reconfigure the transistors in the computer processors. This advance laid the groundwork for the many of the digital technologies that have revolutionized our lives.

“If you needed to directly program the chip installed in your computer in order to use it, modern information technologies would not exist,” Wehner explains. “As such, the ability to program and run applications without needing to know what the chip even is has been key in making networks like the Internet actually useful.”

Quantum and classical

The users of nascent quantum computers would also benefit from an operating system that allows quantum (and classical) computers to be connected in networks. Not least because most people are not familiar with the intricacies of quantum information processing.

However, quantum computers are fundamentally different from their classical counterparts, and this means a host of new challenges faces those developing network operating systems.

“These include the need to execute hybrid classical–quantum programs, merging high-level classical processing (such as sending messages over a network) with quantum operations (such as executing gates or generating entanglement),” Wehner explains.

Within these hybrid programs, quantum computing resources would only be used when specifically required. Otherwise, routine computations would be offloaded to classical systems, making it significantly easier for developers to program and run their applications.

No standardized architecture

In addition, Wehner’s team considered that, unlike the transistor circuits used in classical systems, quantum operations currently lack a standardized architecture – and can be carried out using many different types of qubits.

Wehner’s team addressed these design challenges by creating a QNodeOS, which is a hybridized network operating system. It combines classical and quantum “blocks”, that provide users with a platform for performing quantum operations.

“We implemented this architecture in a software system, and demonstrated that it can work with different types of quantum hardware,” Wehner explains. The qubit-types used by the team included the electronic spin states of nitrogen–vacancy defects in diamond and the energy levels of individual trapped ions.

Multi-tasking operation

“We also showed how QNodeOS can perform advanced functions such as multi-tasking. This involved the concurrent execution of several programs at once, including compilers and scheduling algorithms.”

QNodeOS is still a long way from having the same impact as UNIX and other early operating systems. However, Wehner’s team is confident that QNodeOS will accelerate the development of future quantum networks.

“It will allow for easier software development, including the ability to develop new applications for a quantum Internet,” she says. “This could open the door to a new area of quantum computer science research.”

The research is described in Nature.

The post Operating system for quantum networks is a first appeared first on Physics World.

Epithelial cells send electrical signals, possibly to communicate

3 avril 2025 à 11:05

The nervous system is often considered the body’s wiring, sending electrical signals to communicate needs and hazards between different parts of the body. However, researchers at the University of Massachusetts at Amherst have now also measured bioelectronic signals propagating from cultured epithelial cells, as they respond to a critical injury.

“Cells are pretty amazing in terms of how they are making collective decisions, because it seems like there is no centre, like a brain,” says researcher Sunmin Yu, who likens epithelial cells to ants in the way that they gather information and solve problems. Alongside lab leader Steve Granick, Yu reports this latest finding in Proceedings of the National Academy of Sciences, suggesting a means for the communication between cells that enables them to coordinate with each other.

While neurons function by bioelectric signals, and punctuated rhythmic bioelectrical signals allow heart muscle cells to keep the heart pumping blood throughout our body, when it comes to intercell signals for any other type of cell, the most common hypothesis is the exchange of chemical cues. Yu, however, had noted from previous work by other groups that the process of “extruding” wounded epithelial cells to get rid of them involved increased expression of the relevant proteins at some distance from the wound itself.

“Our thought process was to inquire about the mechanism by which information could be transmitted over the necessary long distance,” says Yu. She realised that common molecular signalling mechanisms, such as extracellular signal-regulated kinase 1/2 (ERK), which has a speed of around 1 mm/s, would be rather slow as a potential conduit.

Epithelial signals measure up

Yu and Granick grew a layer of epithelial cells on a microelectrode array (MEA). While other approaches to measuring electrical activity in cultured cells exist, an MEA has the advantage of combining electrical sensitivity with a long range, enabling the researchers to collect both temporal and spatial information on electrical activity. They then “wounded” the cells by exposing them to an intense focused laser beam.

Following the wound, the researchers observed electrical potential changes with comparable amplitudes and similar shapes to those observed in neurons, but over much longer periods of time. “The signal propagation speed we measured is about 1000 times slower than neurons and 10 times faster than ERK,” says Yu, expressing great interest in whether the “high-pitch speaking” neurons and heart tissue cells communicate with these “low-pitch speaking” epithelial cells, and if so, how.

The researchers noted an apparent threshold in the amplitude of the generated signal required for it to propagate. But for those that met this threshold, propagation of the electric signals spanned regions up to 600 µm for as long as measurements could be recorded, which was 5 h. Given the mechanical forces generated during “cell extrusion”, the researchers hypothesized the likely role of mechanosensitive proteins in generating the signals. Sure enough, inhibiting the mechanosensitive ion channels shut down the generation of electrical signals.

Yu and Granick highlight previous suggestions that electrical potentials in epithelial cells may be important for regulating the coordinated changes that take place during embryogenesis and regeneration, as well as being implicated in cancer. However, this is the first observation of such electrical potentials being generated and propagating across epithelial tissue.

“Yu and Granick have discovered a remarkable new form of electrical signalling emitted by wounded epithelial cells – cells traditionally viewed as electrically passive,” says Seth Fraden, whose lab at Brandeis University in Massachusetts in the US investigates a range of soft matter topics but was not involved in this research.

Fraden adds that it raises an “intriguing” question: “What is the signal’s target? In light of recent findings by Nathan Belliveau and colleagues, identifying the protein Galvanin as a specific electric-field sensor in immune cells, a compelling hypothesis emerges: epithelial cells send these electric signals as distress calls and immune cells – nature’s healers – receive them to rapidly locate and respond to tissue injuries. Such insights may have profound implications for developing novel regenerative therapies and bioelectric devices aimed at accelerating wound healing.”

Adam Ezra Cohen, whose team at Harvard University in the US focuses on innovative technology for probing molecules and cells, and who was not directly involved in this research, also finds the research “intriguing” but raises numerous questions: “What are the underlying membrane voltage dynamics?  What are the molecular mechanisms that drive these spikes? Do similar things happen in intact tissues or live animals?” he asks, adding that techniques such as patch clamp electrophysiology and voltage imaging could address these questions.

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index.feed.received.yesterday — 2 avril 20256.5 📰 Sciences English

Frontgrade Gaisler Launches New GRAIN Line and Wins SNSA Contract to Commercialize First Energy-Efficient Neuromorphic AI for Space Applications

2 avril 2025 à 18:31
Frontgrade logo

Gothenburg, Sweden (April 2, 2025) – The Swedish National Space Agency (SNSA) has awarded Frontgrade Gaisler, a leading provider of radiation-hardened microprocessors for space missions, a contract to commercialize the […]

The post Frontgrade Gaisler Launches New GRAIN Line and Wins SNSA Contract to Commercialize First Energy-Efficient Neuromorphic AI for Space Applications appeared first on SpaceNews.

Zwitterions make medical implants safer for patients

2 avril 2025 à 17:00

A new technique could reduce the risk of blood clots associated with medical implants, making them safer for patients. The technique, which was developed by researchers at the University of Sydney, Australia, involves coating the implants with highly hydrophilic molecules known as zwitterions, thereby inhibiting the build-up of clot-triggering proteins.

Proteins in blood can stick to the surfaces of medical implants such as heart valves and vascular stents. When this happens, it produces a cascade effect in which multiple mechanisms lead to the formation of extensive clots and fibrous networks. These clots and networks can impair the function of implanted medical devices so much that invasive surgery may be required to remove or replace the implant.

To prevent this from happening, the surfaces of implants are often treated with polymeric coatings that resist biofouling. Hydrophilic polymeric coatings such as polyethylene glycol are especially useful, as their water-loving nature allows a thin layer of water to form between them and the surface of the implants, held in place via hydrogen and/or electrostatic bonds. This water layer forms a barrier that prevents proteins from sticking, or adsorbing, to the implant.

An extra layer of zwitterions

Recently, researchers discovered that polymers coated with an extra layer of small molecules called zwitterions provided even more protection against protein adsorption. “Zwitter” means “hybrid” in German; hence, zwitterions are molecules that carry both positive and negative charge, making them neutrally charged overall. These molecules are also very hydrophilic and easily form tight bonds with water molecules. The resulting layer of water has a structure that is similar to that of bulk water, which is energetically stable.

A further attraction of zwitterionic coatings for medical implants is that zwitterions are naturally present in our bodies. In fact, they make up the hydrophilic phospholipid heads of mammalian cell membranes, which play a vital role in regulating interactions between biological cells and the extracellular environment.

Plasma functionalization

In the new work, researchers led by Sina Naficy grafted nanometre-thick zwitterionic coatings onto the surfaces of implant materials using a technique called plasma functionalization. They found that the resulting structures reduce the amount of fibrinogen proteins that adsorb onto the implants by roughly nine-fold and decrease blood clot formation (thrombosis) by almost 75%.

Naficy and colleagues achieved their results by optimizing the density, coverage and thickness of the coating. This was critical for realizing the full potential of these materials, they say, because a coating that is not fully optimized would not reduce clotting.

Naficy tells Physics World that the team’s main goal is to enhance the surface properties of medical devices. “These devices when implanted are in contact with blood and can readily cause thrombosis or infection if the surface initiates certain biological cascade reactions,” he explains. “Most such reactions begin when specific proteins adsorb on the surface and activate the next stage of cascade. Optimizing surface properties with the aid of zwitterions can control / inhibit protein adsorption, hence reducing the severity of adverse body reactions.”

The researchers say they will now be evaluating the long-term stability of the zwitterion-polymer coatings and trying to scale up their grafting process. They report their work in Communications Materials and Cell Biomaterials.

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CERN releases plans for the ‘most extraordinary instrument ever built’

2 avril 2025 à 13:56

The CERN particle-physics lab near Geneva has released plans for the 15bn SwFr (£13bn) Future Circular Collider (FCC) – a huge 91 km circumference machine. The three-volume feasibility study, released on 31 March, calls for the giant accelerator to collide electrons with positrons to study the Higgs boson in unprecedented detail. If built, the FCC would replace the 27 km Large Hadron Collider (LHC), which will come to an end in the early 2040s.

Work on the FCC feasibility study began in 2020 and the report examines the physics objectives, geology, civil engineering, technical infrastructure and territorial and environmental impact. It also looks at the R&D needed for the accelerators and detectors as well as the socioeconomic benefits and cost.

The study, involving some 150 institutes in over 30 countries, took into account some 100 different scenarios for the collider before landing on a ring circumference of 90.7 km that would be built underground at a depth of about 200 m, on average.

The FCC would also contain eight surface sites to access the tunnel with seven in France and one in Switzerland, and four main detectors. “The design is such that there is minimal impact on the surface, but with the best possible physics output,” says FCC study leader Michael Benedikt.

The funding model for the FCC is still a work in progress, but it is estimated that at least two-thirds of the cost of building the FCC-ee will come from CERN’s 24 member states.

Four committees will now review the feasibility study, beginning with CERN’s scientific committee in July. It will then go to a cost-review panel before being reviewed by the CERN council’s scientific and finance committees. In November, the CERN council will then examine the proposal with a decision to go ahead taken in 2028.

If given the green light, construction on the FCC electron-positron machine, dubbed FCC-ee, would begin in 2030 and it would start operations in 2047, a few years after the High Luminosity LHC (HL-LHC) closes down, and run for about 15 years.  It’s main aim would be to study the Higgs boson with a much better precision that the LHC.

Artist impression of the FCC-hh
To the energy frontier: if built, the FCC-hh would begin operation in 2073 and run to the end of the century (courtesy: PIXELRISE)

The FCC feasibility study then calls for a hadron machine, dubbed FCC-hh, to replace the FCC-ee in the existing 91 km tunnel. It would be a “discovery machine”, smashing together protons at high energy with the aim of creating new particles. If built, the FCC-hh will begin operation in 2073 and run to the end of the century.

The original design energy for the FCC-hh was to reach 100 TeV but that has now been reduced to 85 TeV.  That is mostly due to the uncertainty in magnet technology. The HL-LHC will use 12 T superconducting quadrupole magnets made from niobium-tin (Nb3Sn) to squeeze the beams to boost the luminosity.

CERN engineers think it is possible to increase that to 14 T and if this was used for the FCC it would result in a collision centre-of-mass energy of about 85 TeV. “It’s a prudent approach at this stage,” noted Fabiola Gianotti, current CERN director-general, adding that the FCC would be “the most extraordinary instrument ever built.”

The original design called for high-temperature superconducting magnets, such as so-called ReBCO tapes, and CERN is looking into such technology. If it came to fruition in the necessary timescales and was implemented in the FCC-hh then it could push the energy to 120 TeV.

China plans

One potential spanner in the works is China’s plans for a very similar machine called the Circular Election-Positron Collider (CEPC). A decision on the CEPC could come this year with construction beginning in 2027.

Yet officials at CERN are not concerned. They point to the fact that many different colliders have been built by CERN, which has the expertise as well as infrastructure to build such a huge collider.  “Even if China goes ahead, I hope the decision is to compete,” says CERN council president Costas Fountas. “Just like Europe did with the LHC when the US started to build the [cancelled] Superconducting Super Collider.”

If the CERN council decides, however, not to go ahead with the FCC, then Gianotti says that other designs to replace the LHC are still on the table such as a linear machine or a demonstrator muon collider.

The post CERN releases plans for the ‘most extraordinary instrument ever built’ appeared first on Physics World.

So you think you know Roger Penrose? Be prepared to be shocked

2 avril 2025 à 13:00

I was unprepared for the Roger Penrose that I met in The Impossible Man. As a PhD student training in relativity and quantum gravity at the Perimeter Institute for Theoretical Physics in Waterloo, Canada, I once got to sit next to Penrose. Unsure of what to say to the man whose ideas about black-hole singularities are arguably why I took an interest in becoming a physicist, I asked him how he had come up with the idea for the space-time diagrams now known as “Penrose diagrams”.

Penrose explained to me that he simply couldn’t make sense of space-time without them, that was all. He spoke in kind terms, something I wasn’t quite used to. I was more familiar with people reacting as if my questions were stupid or impertinent. What I felt from Penrose – who eventually shared the 2020 Nobel Prize for Physics with Reinhard Genzel and Andrea Ghez for his work on singularities – was humility and generosity.

The Penrose of The Impossible Man isn’t so much humble as oblivious and, in my reading, quite spoiled

In hindsight, I wonder if I overread him, or if, having been around too many brusque theoretical physicists, my bar as a PhD student was simply too low. The Penrose of The Impossible Man isn’t so much humble as oblivious and, in my reading, quite spoiled. As a teenager he was especially good at taking care of his sister and her friends, generous with his time and thoughtfulness. But it ends there.

As we learn in this biography – written by the Canadian journalist Patchen Barss – one of those young friends, Judith Daniels, later became the object of Penrose’s affection when he was a distinguished faculty member at the University of Oxford in his 40s. A significant fraction of the book is centred on Penrose’s relationship with Daniels, whom he became reacquainted with in the early 1970s when she was an undergraduate studying mathematics at John Cass College in London.

At the time Penrose was unhappily married to Joan, an American he’d met in 1958 when he was a postdoc at the University of Cambridge. In Barss’s telling, Penrose essentially forces Daniels into the position of muse. He writes her copious letters explaining his intellectual ideas and communicating his inability to get his work done without replies from her, which he expects to contain critical analyses of his scientific proposals.

The letters are numerous and obsessive, even when her replies are thin and distant. Eventually, Penrose also begins to request something more – affection and even love. He wants a relationship with her. Barss never exactly states that this was against Daniels’s will, but he offers readers sufficient details of her letters to Penrose that it’s hard to draw another conclusion.

Unanswered questions

Barss was able to read her letters because they had been returned to Penrose after Daniels’s death in 2005. Penrose, however, never re-examined any of them until Barss interviewed him for this biography. This raises a lot of questions that remain unanswered by the end of the book. In particular, why did Daniels continue to participate in a correspondence that was eventually thousands of pages long on Penrose’s side?

Judith Daniels was a significant figure in Penrose’s life, yet her death and memory seem to have been unremarkable to him for much of his later life

My theory is that Daniels felt she owed it to this great man of science. She also confesses at one point that she had a childhood crush on him. Her affection was real, even if not romantic; it is as if she was trapped in the dynamic. Penrose’s lack of curiosity about the letters after her death is also strange to me. Daniels was a significant figure in his life, yet her death and memory seem to have been unremarkable to him for much of his later life.

By the mid-1970s, when Daniels was finally able to separate herself from what was – on Penrose’s side – an extramarital emotional affair, Penrose went seeking new muses. They were always female students of mathematics and physics.

Just when it seems like we’ve met the worst of Penrose’s treatment of women, we’re told about his “physical aggression” toward his eventual ex-wife Joan and his partial abandonment of the three sons they had together. This is glossed over very quickly. And it turns out there is even more.

Penrose, like many of his contemporaries, primarily trained male students. Eventually he did take on one woman, Vanessa Thomas, who was a PhD student in his group at Oxford’s Mathematical Institute, where he’d moved in 1972.

Thomas never finished her PhD; Penrose pursued her romantically and that was the end of her doctorate. As scandalous as this is, I didn’t find the fact of the romance especially shocking because it is common enough in physics, even if it is increasingly frowned upon and, in my opinion, generally inappropriate. For better or worse, I can think of other examples of men in physics who fell in love with women advisees.

But in all the cases I know of, the woman has gone on to complete her degree either under his or someone else’s supervision. In these same cases, the age difference was usually about a decade. What happened with Thomas – who married Penrose in 1988 – seems like the worst-case scenario: a 40-year age difference and a budding star of mathematics, reduced to serving her husband’s career. Professional boundaries were not just transgressed, but obliterated.

Barss chooses not to offer much in the way of judgement about the impact that Penrose had on the women in science whom he made into muses and objects of romantic affection. The only exception is Ivette Fuentes, who was already a star theoretical physicist in her own right when Penrose first met her in 2012. Interview snippets with Fuentes reveal that the one time Penrose spoke of her as a muse, she rejected him and their friendship until he apologized.

No woman, it seems, had ever been able to hold him to the fire before. Fuentes does, however, describe how Penrose gave her an intellectual companion, something she’d previously been denied by the way the physics community is structured around insider “families” and pedigrees. It is interesting to read this in the context of Penrose’s own upbringing as landed gentry.

Gilded childhood

An intellectually precocious child growing up in 1930s England, Penrose is handed every resource for his intellectual potential to blossom. When he notices a specific pattern linking addition and multiplication, an older sibling is on hand to show him there’s a general rule from number theory that explains the pattern. The family at this point, we’re told, has a cook and a maid who doubles as a nanny. Even in a community of people from well-resourced backgrounds, Penrose stands out as an especially privileged example.

When the Second World War starts, his family readily secures safe passage to a comfortable home in Canada – a privilege related to their status as welcomed members of Britain’s upper class and one that was not afforded to many continental European Jewish families at the time (Penrose’s mother and therefore Penrose was Jewish by descent). Indeed, Canada admitted the fewest Jewish refugees of any Allied nation and famously denied entry to the St Louis, which was sent back to Europe, where a third of its 937 Jewish passengers were murdered in the Holocaust.

In Ontario, the Penrose children have a relatively idyllic experience. Throughout the rest of his childhood and his adult life, the path has been continuously smoothed for Penrose, either by his parents (who bought him multiple homes) or mentors and colleagues who believed in his genius. One is left wondering how many other people might have such a distinguished career if, from birth, they are handed everything on a silver platter and never required to take responsibility for anything.

To tell these and later stories, Barss relies heavily on interviews with Penrose. Access to their subject for any biographer is tricky. While it creates a real opportunity for the author, there is also the challenge of having a relationship with someone whose memories you need to question. Barss doesn’t really interrogate Penrose’s memory but seems to take them as gospel.

During the first half of the book, I wondered repeatedly if The Impossible Man is effectively a memoir told in the third person. Eventually, Barss does allow other voices to tell the story. Ultimately, though, this is firmly a book told from Penrose’s point of view. Even the inclusion of Daniels’s story was at least in part at Penrose’s behest.

I found myself wanting to hear more from the women in Penrose’s life. Penrose often saw himself following a current determined by these women. He came, for example, to believe his first wife had essentially trapped him in their relationship by falling for him.

Penrose never takes responsibility for any of his own actions towards the women in his life. So I wondered: how did they see it? What were their lives like? His ex-wife Joan (who died in 2019) and estranged wife Vanessa, who later became a mathematics teacher, both gave interviews for the book. But we learn little about their perspective on the man whose proclivities and career dominated their own lives.

One day there will be another biography of Penrose that will necessarily have distance from its subject because he will no longer be with us. The Impossible Man will be an important document for any future biographer, containing as it does such a close rendering of Penrose’s perspective on his own life.

The cost of genius

When it comes to describing Penrose’s contributions to mathematics and physics, the science writing, especially in the early pages, sings. Barss has a knack for writing up difficult ideas – whether it’s Penrose’s Nobel-prize-winning work on singularities or his attempt at quantum gravity, twistor theory. Overall, the luxurious prose makes the book highly readable.

Sometimes Barss indulges cosmic flourishes in a way that appears to reinforce Penrose’s perspective that the universe is happening to him rather than one over which he has any influence. In the end, I don’t know if we learn the cost of genius, but we certainly learn the cost of not recognizing that we are a part of the universe that has agency.

The final chapter is really Barss writing about himself and Penrose, and the conversations they have together. Penrose has macular degeneration now, so while both are on a visit to Perimeter in 2019, Barss reads some of his letters to Judith back to Penrose. Apparently, Penrose becomes quite emotional in a way that it seems no-one had ever seen – he weeps.

After that, he asks Barss to include the story about Judith. So, on some level, he knows he has erred.

The end of The Impossible Man is devastating. Barss describes how he eventually gains access to two of Penrose’s sons (three with Joan and one with Vanessa). In those interviews, he hears from children who have been traumatized by witnessing what they call “physical aggression” toward their mother. Even so, they both say they’d like to improve their relationship with their father.

Barss then asks a 92-year-old Penrose if he wants to patch things up with his family. His reply: “I feel my life is busy enough and if I get involved with them, it just distracts from other things.” As Barss concludes, Penrose is persistently unwilling to accept that in his life, he has been in the driver’s seat. He has had choices and doesn’t want to take responsibility for that. This, as much as Penrose’s intellectual interests and achievements, is the throughline of the text.

Penrose has shown that he doesn’t really care what others think, as long as he gets what he wants scientifically

The Penrose we meet at the end of The Impossible Man has shown that he doesn’t really care what others think, as long as he gets what he wants scientifically. It’s clear that Barss has a real affection for him, which makes his honesty about the Penrose he finds in the archives all the more remarkable. Perhaps motivated by generosity toward Penrose, Barss also lets the reader do a lot of the analysis.

I wonder, though, how many physicists who are steeped in this culture, and don’t concern themselves with gender equity issues, will miss how bad some of Penrose’s behaviour has been, as his colleagues at the time clearly did. The only documented objections to his behaviour seem more about him going off the deep end with his research into consciousness, cyclic theory and attacks on cosmic inflation.

As I worked on this review, I considered whether a different reviewer would have simply complained that the book has lots of stuff about Penrose’s personal messes that we don’t need to know. Maybe, to other readers, Penrose doesn’t come off quite as badly. For me, I prefer the hero I met in person rather than in the pages of this book. The Impossible Man is an important text, but it’s heartbreaking in the end.

  • 2024 Basic Books (US)/Atlantic Books (UK) 352pp $32/£25hb
  • In 2015 Physics World’s Tushna Commissariat interviewed Roger Penrose about his career. You can watch the video below

 

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Solar cell greenhouse accelerates plant growth

2 avril 2025 à 10:30

Agrivoltaics is an interdisciplinary research area that lies at the intersection of photovoltaics (PVs) and agriculture. Traditional PV systems used in agricultural settings are made from silicon materials and are opaque. The opaque nature of these solar cells can block sunlight reaching plants and hinder their growth. As such, there’s a need for advanced semi-transparent solar cells that can provide sufficient power but still enable plants to grow instead of casting a shadow over them.

In a recent study headed up at the Institute for Microelectronics and Microsystems (IMM) in Italy, Alessandra Alberti and colleagues investigated the potential of semi-transparent perovskite solar cells as coatings on the roof of a greenhouse housing radicchio seedlings.

Solar cell shading an issue for plant growth

Opaque solar cells are known to induce shade avoidance syndrome in plants. This can cause morphological adaptations, including changes in chlorophyll content and an increased leaf area, as well as a change in the metabolite profile of the plant. Lower UV exposure can also reduce polyphenol content – antioxidant and anti-inflammatory molecules that humans get from plants.

Addressing these issues requires the development of semi-transparent PV panels with high enough efficiencies to be commercially feasible. Some common panels that can be made thin enough to be semi-transparent include organic and dye-sensitized solar cells (DSSCs). While these have been used to provide power while growing tomatoes and lettuces, they typically only have a power conversion efficiency (PCE) of a few percent – a more efficient energy harvester is still required.

A semi-transparent perovskite solar cell greenhouse

Perovskite PVs are seen as the future of the solar cell industry and show a lot of promise in terms of PCE, even if they are not yet up to the level of silicon. However, perovskite PVs can also be made semi-transparent.

Laboratory-scale greenhouse
Experimental set-up The laboratory-scale greenhouse. (Courtesy: CNR-IMM)

In this latest study, the researchers designed a laboratory-scale greenhouse using a semi-transparent europium (Eu)-enriched CsPbI3 perovskite-coated rooftop and investigated how radicchio seeds grew in the greenhouse for 15 days. They chose this Eu-enriched perovskite composition because CsPbI3 has superior thermal stability compared with other perovskites, making it ideal for long exposures to the Sun’s rays. The addition of Eu into the CsPbI3 structure improved the perovskite stability by minimizing the number of intrinsic defects and increasing the surface-to-volume ratio of perovskite grains.

Alongside this stability, this perovskite also has no volatile components that could potentially effuse under high surface temperatures. It also typically possesses a high PCE – the record for this composition is 21.15%, which is significantly higher and much more commercially feasible than previously possible with organic PVs and DSSCs. This perovskite, therefore, provides a good trade-off between the PCE that can be achieved while transmitting enough light to allow the seedlings to grow.

Low light conditions promote seedling growth

Even though the seedlings were exposed to lower light conditions than natural light, the team found that they grew more quickly, and with bigger leaves, than those under glass panels. This is attributed to the perovskite acting as a filter for only red light to pass through. And red light is known to improve the photosynthetic efficiency and light absorption capabilities of plants, as well as increase the levels of sucrose and hexose within the plant.

The researchers also found that seedlings grown under these conditions had different gene expression patterns compared with those grown under glass. These expression patterns were associated with environmental stress responses, growth regulation, metabolism and light perception, suggesting that the seedlings naturally adapted to different light conditions – although further research is needed to see whether these adaptations will improve the crop yield.

Overall, the use of perovskite PVs strikes a good balance between being able to provide enough power to cover the annual energy needs for irrigation, lighting and air conditioning, while still allowing the seedlings to grow – and grow much quicker and faster. The team suggest that the perovskite solar cells could help with indoor food production operations in the agricultural sector as a potentially affordable solution, although more work now needs to be done on much larger scales to test the technology’s commercial feasibility.

The research is published in Nature Communications.

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In Search of the Last Wild Axolotls

2 avril 2025 à 11:00
Using environmental DNA analysis and traditional fishing techniques, researchers are seeking answers about the current population of axolotls in their natural habitat. The numbers are alarming.

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