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Patterned electrodes reveal how bubble spacing affects hydrogen production efficiency

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Patterned electrodes reveal how bubble spacing affects hydrogen production efficiency


The bubble growth curves of bubbles. Credit: Small (2025). DOI: 10.1002/smll.202505728

As part of a Special Invitation Collection celebrating the 15th anniversary of the Global Young Academy (GYA), a UT team led by David Fernandez Rivas has presented new insights into how bubbles behave during hydrogen production. By designing electrodes that guide the formation and merging of bubbles, the team has taken a significant step toward enhancing the efficiency of electrolysis for green hydrogen production.

The GYA was launched in 2010 with strong University of Twente involvement, as it was co-founded by UT professors Hans Hilgenkamp and Wilfred van der Wiel. Since then, it has grown into a leading platform for early-career researchers worldwide. To mark its 15th anniversary, the academy invited contributions from members and alumni to showcase how tackle complex, global problems.

“This special invitation feels like closing a circle,” says David Fernandez Rivas, now an alumnus of the GYA. “UT was there at the birth of the academy, and 15 years later, we can show how our research over the past 10 years in Twente continues that mission: combining curiosity with real-world impact.”

Tiny cavities, controlled bubbles

Hydrogen is often produced through electrolysis, where bubbles form on electrodes as water splits into hydrogen and oxygen. But uncontrolled bubbles can block surfaces, reducing efficiency. However, bubbles often appear at random locations on electrode surfaces, complicating efforts to better understand them.

To overcome this, the UT researchers with access to the Nanolab cleanroom from the MESA+ Institute created patterned with tiny hydrophobic cavities. These are places where bubbles can consistently form, which lowers the randomness and therefore increases the controllability of electrochemical processes.

What makes this study stand out is that the team varied the distance between the cavities. This allowed them to see how bubbles grow, merge, and detach depending on how close their neighbors are.

They discovered that when the cavities are closer together, bubbles break off more often and in smaller sizes. This also helps reduce the buildup of gas around the bubbles. However, it also leads to more coverage on the electrode, which is a bit of a trade-off that needs to be balanced. The work is published in the journal Small.

“We showed that are not just a nuisance on electrodes, but can actually help drive gas away from the electrode if cleverly managed,” explains Dr. Akash Raman, who carried out the research as part of his Ph.D. “By adjusting the spacing of the cavities, we identified trade-offs between blocking the electrode and improving transport.”

More information:
Akash Raman et al, Electrolytic Bubble Coalescence on Hydrophobic Cavity Arrays Determines Departure Radius and Lowers Electrolyte Supersaturation, Small (2025). DOI: 10.1002/smll.202505728

Journal information:
Small


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The Catastrophic Swatch x Audemars Piguet Launch Was Entirely Predictable and Utterly Avoidable

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The Catastrophic Swatch x Audemars Piguet Launch Was Entirely Predictable and Utterly Avoidable


The note from the communications team then, quite remarkably, lists some stats in an attempt to paint the launch in a positive light, as opposed the retail bin-fire it seemingly was: “We have received millions of clicks on our website. This new collaboration is literally making social media explode, with over 6 billion views within one week; by now, it is already 11 billion. All in all, the Royal Pop Collection is captivating the entire world, not least because the Royal Pop is, quite surprisingly, not a wristwatch.”

Audemars Piguet seems unhappy with how Swatch has handled the launch of its collaboration on the Royal Pop. AP told WIRED that “we understand the questions around the Royal Pop launch experience. As retail operations are handled by Swatch and their local teams, Swatch is best placed to comment on the operational handling of the launch. From AP’s perspective, safety and a positive experience for clients and teams remain the priority.” The brand did not respond when asked if it considered Swatch’s handling of the Royal Pop launch a “safe and positive experience”.

The madness of the Royal Pop launch is that, considering all that could have been learned from the MoonSwatch release in 2022, Swatch decided to repeat the playbook that went so badly wrong four years ago. This is a move, according to experts, that was entirely avoidable and utterly unnecessary.

Hype With No Control

“Luxury drops cannot rely on surprise, scarcity and social frenzy as the strategy, then act surprised when human behaviour follows,” says Kate Hardcastle, author of The Science of Shopping and advisor to brands including Disney, Mastercard, Klarna and American Express. “Retailers are already dealing with heightened tensions around theft, aggression and crowd management globally. Add a highly restricted product, long queues, resale economics, social media amplification and the emotional intensity attached to luxury access, and the environment can escalate very quickly if not expertly managed.”

Hardcastle confirms that what is particularly difficult for Swatch here is that the MoonSwatch launch already provided a live blueprint of the risks. “Once a brand has experienced scenes involving crowd surges, disappointment and policing,” she says, “the obligation shifts from reacting to proactively engineering a safer customer experience. Successful luxury houses increasingly control the experience with far greater precision.”

Neil Saunders, managing director of retail at Global Data, is even more candid. “The chaos does not reflect well on Swatch, and it probably makes Audemars Piguet wonder what on Earth it has gotten itself into,” he says. “Wanting to create some hype is understandable, but not being able to control it becomes damaging both commercially and for the brand image. Swatch should understand this better than most as it has been through this before with MoonSwatch.”

Not only Saunders and Hardcastle, but scores of commenters on Swatch’s Instagram post, point out well-known and obvious solutions that would have mitigated or entirely avoided the Royal Pop’s shambolic release.

“We have seen other premium or limited launches use staggered collection windows, verified appointment systems, geo-ticketing, VIP allocation tiers, timed QR access, private client previews and controlled queue technology to reduce volatility while preserving excitement,” says Hardcastle, adding that some combine digital ballots with curated in-store experiences so consumers feel part of an occasion rather than participants in a scramble.



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The Backward Logic of Chickenpox Parties

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The Backward Logic of Chickenpox Parties


Anyone who has had chickenpox shares one distinct memory: the relentless, all-consuming itch.

Ciara DiVita was only 3 years old when she caught the virus, but she remembers it well—along with the oven mitts she was made to wear to stop herself scratching. She also recalls being taken to hang out with her cousin while covered in blisters, in the hopes of deliberately infecting them.

DiVita, now 30, was actually the second in the chain, having been taken by her parents to catch chickenpox from an infectious friend. “I imagine the chain continued and my cousin gave it to someone else at a chickenpox play date,” she says.

A lot has changed over the past three decades, most notably the development of a chickenpox vaccine, meaning the virus is no longer the childhood rite of passage it once was.

Thanks to the vaccine’s success, children today are much less likely to be exposed to the infection at school or on the playground.

Chickenpox parties are also largely considered a relic of the past—a strategy many Gen X and millennial children were subjected to before vaccines became routine. But much like the virus itself—latent, opportunistic—they haven’t disappeared entirely.

Before a vaccine existed, chickenpox, which is caused by the varicella-zoster virus, felt unavoidable. In temperate countries like the UK and the US, around 90 percent of children caught the virus before adolescence (in tropical countries the average age of infection is higher).

It’s nothing to do with chickens. The splotchy, scratchy, highly contagious disease is possibly named after the French word for chickpea, pois chiche, according to one theory, because the round bumps caused by the virus resemble their size and shape. While most infant cases are mild, adolescents and adults are more likely to develop severe complications.

This is where the idea of “getting it over and done with” emerged from, according to Maureen Tierney, associate dean of clinical research and public health at Creighton University in Omaha, Nebraska.

“You were trying to have your child get the disease when they were at the greatest chance of not having complications,” Tierney says, explaining that, generally speaking, the older the patient, the more severe the infection can be.

While varicella-zoster is usually a mild, self-limiting disease in children, it can be much more severe—and sometimes life-threatening—in adults.

“I had an otherwise healthy adult patient who died of chickenpox pneumonia when I was first practicing,” Tierney says. “You never forget those scenarios.”

The virus spreads rapidly through respiratory droplets and contact with fluid from its characteristic blisters, meaning if one child contracts it, siblings and classmates are likely to be next, if unvaccinated.

Before the existence of social media, the idea that children should deliberately infect each other spread just as rapidly around communities—in conversations in the school yard, church groups, and pediatric waiting rooms—leading to the popularity of so-called chickenpox parties.

Parents swapped advice about oatmeal baths and calamine lotion and arranged to bring children together when one was thought to be infectious—despite the practice never being an official medical recommendation.

“They thought, well, if it’s going to happen to my kid anyway, it might as well happen in a controlled environment,” says Monica Abdelnour, a pediatric infectious disease specialist at Phoenix Children’s Hospital. “The families were ready to encounter this infection, deal with it, and then move on.”

While the majority of children who develop chickenpox feel well again within a week or two, around three in every 1,000 infected experience a severe complication such as pneumonia, serious bacterial skin infections, encephalitis (inflammation of the brain), or meningitis.



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A Danish Couple’s Maverick African Research Finds Its Moment in RFK Jr.’s Vaccine Policy

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A Danish Couple’s Maverick African Research Finds Its Moment in RFK Jr.’s Vaccine Policy


In 1996, Guinea-Bissau seemed like an ideal research post for budding pediatrician Lone Graff Stensballe. Her supervisor, a fellow Dane named Peter Aaby, had spent nearly two decades collecting data on 100,000 people living in the mud brick homes of the West African country’s capital.

Aaby and his partner, Christine Stabell Benn, believed that the years of research in the impoverished country had yielded a major discovery about vaccines—and what they described as “non-specific effects”: The measles and tuberculosis vaccines, which were derived from live, weakened viruses and bacteria, they said, boosted child survival beyond protecting against those particular pathogens.

But, the scientists said, shots made from deactivated whole germs, or pieces of them, such as the diphtheria-tetanus-pertussis (DTP) shot, caused more deaths—especially in little girls—than getting no vaccine at all.

The World Health Organization repeatedly and inconclusively examined these astonishing findings. They tended to elicit shrugs from other global health researchers, who found Aaby’s research techniques unusual and his results generally impossible to replicate.

Then came Donald Trump, Covid, and the administrative reign of anti-vaccine advocate Robert F. Kennedy Jr.

Suddenly, Aaby and Benn weren’t just sending up distant smoke signals from a far corner of the planet. They were confidently voicing their views and policy prescriptions online and in medical journals. The “framework” for “testing, approving, and regulating vaccines needs to be updated to accommodate non-specific effects,” their team wrote in a 2023 review.

And the Trump administration has taken notice.

“They became more strident in saying that their findings were real and that the world needed to do something about it,” said Kathryn Edwards, a Vanderbilt University vaccinologist who has been aware of Aaby’s work since the 1990s. “And they became more aligned with RFK.”

Kennedy, as secretary of the Department of Health and Human Services, cited one of Aaby’s papers to justify slashing $2.6 billion in US support for Gavi, a global alliance of vaccination initiatives. The cut could result in 1.2 million preventable deaths over five years in the world’s poorest countries, the nonprofit agency has estimated. Kennedy has frozen $600 million in current Gavi funding over largely debunked vaccine safety claims.

Kennedy described the 2017 paper as a “landmark study” by “five highly regarded mainstream vaccine experts” that found that girls who received a diphtheria-tetanus-pertussis, or DTP, shot were 10 times more likely to die from all causes than unvaccinated children.

In fact, the study was far too small to confidently make such assertions, as Benn acknowledged. In a study of historical data that included 535 girls, four of those vaccinated against DTP in a three-month period of infancy died of unrelated causes, while one unvaccinated girl died during that period. A follow-up published by the same group in 2022 found that the DTP shot by itself had no effect on mortality. Critics say the 2017 study, rather than being a landmark, exemplified the troubling shortfalls they perceive in the Danish team’s research.

As Aaby and Benn’s US profile has risen, scientists in Denmark have set upon the work of their compatriots. In news and journal articles published over the past 18 months, Danish statisticians and infectious disease experts have said the duo’s methods were unorthodox, even shoddy, and were structured to support preconceived views. A national scientific board is investigating their work.

Stensballe, who worked with Aaby and Benn for 20 years, has been among those voicing doubts.

“It took years to see what I see clearly today, that there is a strange concerning pattern in their work,” Stensballe said in a phone interview from Copenhagen, where she treats children at Rigshospitalet, the city’s largest teaching hospital. She said their work is full of confirmation bias—favoring interpretations that fit their hypotheses.



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