Layered hydrogen silicane for safe, lightweight, and energy-efficient hydrogen carrier

Researchers investigate layered hydrogen silicane as a new solid-state hydrogen carrier, paving the way for novel hydrogen storage systems

Institute of Science Tokyo

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Layered hydrogen silicane (L-HSi) represents a promising solid-state hydrogen carrier that can address the drawbacks of conventional hydrogen storage systems, while being cost-effective and sustainable.

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Credit: Institute of Science Tokyo

Hydrogen, a clean energy source, requires a highly reliable and safe storage system, which is currently lacking. Layered hydrogen silicane (L-HSi) is a promising, safe, lightweight, and energy-efficient solid-state hydrogen carrier with potential for practical utility. This material releases hydrogen when irradiated with low-intensity visible-light sources like sunlight or LEDs. L-HSi represents a new direction for hydrogen carrier system research.

Hydrogen is a promising fuel that can replace conventional fossil fuels as it emits no carbon dioxide during combustion or oxidation and can be produced from a wide range of sources. However, a hydrogen-based economy requires not only clean production but also safe and efficient hydrogen storage and transportation. Current systems pose several drawbacks: compressed hydrogen tanks have low hydrogen densities and pose explosion risks, while liquid hydrogen tanks require extremely low temperatures and considerable energy.

Ammonia is a well-known liquid hydrogen carrier with a high hydrogen density, but its dehydrogenation requires extensive energy and comes with issues such as corrosiveness and toxicity. To solve these issues, researchers have turned towards solid-state hydrogen carrier materials. Unfortunately, most solid-state alloys consist of heavy metals and have limited gravimetric hydrogen capacities.

In a breakthrough, a research team consisting of Mr. Hirona Ito and Professor Masahiro Miyauchi from Institute of Science Tokyo (Science Tokyo), Ms. Mio Nakai and Professor Hideyuki Nakano from Kindai University, and Professor Takahiro Kondo from the University of Tsukuba, Japan, discovered a new solid-state hydrogen carrier called layered hydrogen silicane (L-HSi). Hydrogen can be released from L-HSi by visible light irradiation under ambient temperature and pressure. Their findings were published online in the journal Advanced Optical Materials on December 29, 2025.

L-HSi consists of silicon and hydrogen in a 1:1 ratio and exhibits a high gravimetric hydrogen capacity of 3.44 wt.%. Unlike conventional hydrogen storage systems, it is a stable, solid-state hydrogen carrier that can release hydrogen simply by exposure to low-intensity light sources like sunlight or LEDs.

The researchers synthesized L-HSi via decalcification of CaSi2 in a reaction with HCl and tested its hydrogen release properties. They placed L-HSi powder under an argon atmosphere in a gas-flow-type reactor and irradiated it with a xenon lamp at ambient temperature and pressure. The optical bandgap of L-HSi is 2.13 eV, corresponding to a wavelength of 600 nm, which absorbs visible light. The light was turned on 10 minutes after the experiment began and turned off at the 60-minute mark. During irradiation, the researchers clearly observed gaseous hydrogen formation.

Further heating tests under a dark environment and detailed spectroscopic analysis confirmed that hydrogen release was not due to a photothermal process, but instead, driven by bandgap excitation of L-HSi. Specifically, hydrogen was released when irradiated with wavelengths below 600 nm. The material showed a maximum quantum efficiency of 7.3% at 550 nm.

The researchers also conducted long-term irradiation tests, where L-HSi was dispersed in an organic medium inside the dispersed reactor. Under extended visible-light exposure, about 46.7% of the bonded hydrogen atoms were released. The team also confirmed that hydrogen could be effectively produced using low-intensity, economical light sources, including sunlight and LEDs.

L-HSi is a promising solid-state hydrogen carrier that can open new possibilities for safe, lightweight, and energy-efficient hydrogen storage. Looking forward, their research will focus on improving its reversibility and scalability for practical applications.

 

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About Institute of Science Tokyo (Science Tokyo)
Institute of Science Tokyo (Science Tokyo) was established on October 1, 2024, following the merger between Tokyo Medical and Dental University (TMDU) and Tokyo Institute of Technology (Tokyo Tech), with the mission of “Advancing science and human wellbeing to create value for and with society.”

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Journal

Advanced Optical Materials

DOI

10.1002/adom.202502880 

Method of Research

Experimental study

Subject of Research

Not applicable

Article Title

Visible-Light-Driven Hydrogen Release from Layered Hydrogen Silicane

 

Analyzing submerged fault structures to predict future earthquakes in Türkiye

Researchers create a 3D electromagnetic model of the Marmara Sea region

Institute of Science Tokyo

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This new three-dimensional (3D) model of resistivity beneath the North Anatolian fault will help earth scientists more accurately identify areas at risk of major earthquakes.

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Credit: Institute of Science Tokyo

A new three-dimensional model of the fault beneath the Marmara Sea in Türkiye reveals where a future major earthquake could take place, as reported by researchers from Science Tokyo. Using electromagnetic measurements, the team mapped hidden structures that help explain how earthquakes initiate and where ruptures could occur in this region. The findings help improve earthquake forecasts and could guide disaster prevention strategies for millions living in Istanbul and nearby, where seismic risk is high.

The Republic of Türkiye sits in one of the most seismically active regions of the Earth, featuring interactions between the Eurasian, African, Arabian, and Anatolian plates. Because of this, Türkiye is particularly prone to earthquakes, and many catastrophic ones have been documented since the republic was established. Since the 1939 Erzincan earthquake, which claimed the lives of over 30,000 people, scientists have noticed a peculiar pattern: destructive earthquakes follow a markedly westward migration along what is known as the North Anatolian fault (NAF).

Today, earth scientists theorize that the area beneath the Marmara Sea, which has been seismically silent for over 250 years, is the most probable location of the next large-scale earthquake. However, despite extensive research efforts in the area, the fault structure below the Marmara Sea remains poorly understood, making it hard to pinpoint future earthquake locations and implement optimal disaster mitigation strategies.

Against this background, a research team led by Dr. Yasuo Ogawa, Professor Emeritus and Research Fellow at the Multidisciplinary Resilience Research Center, Institute of Integrated Research, Institute of Science Tokyo (Science Tokyo), Japan (also Visiting Researcher at Tohoku University, Japan), along with Dr. Tülay Kaya-Eken, Assistant Professor at Boğaziçi University, Türkiye, has conducted a study that greatly deepens our knowledge of the properties beneath the NAF in the Marmara Sea. Their work, published online in the journal Geology on December 8, 2025, presents the first three-dimensional (3D) model of this critical subsurface region, providing foundational insights into the underlying processes governing earthquake generation.

To create this model, the researchers employed a large dataset of magnetotelluric measurements taken by more than 20 previously deployed stations. Simply put, magnetotelluric stations can record subtle changes in Earth’s electric and magnetic fields caused by structures deep underground. This information enabled the team to reconstruct, via a process known as 3D inversion, a 3D representation of the electrical resistivity of the region down to depths of tens of kilometers beneath the seafloor.

By analyzing the final model, the team identified many distinct high-resistivity and low-resistivity zones. Since resistivity is inversely related to the presence of water, low-resistivity zones are mechanically weaker, whereas high-resistivity ones are stronger and locked in place. “We believe the resistive anomalies observed signify regions of stress accumulation, shedding light on the ongoing processes of fault mechanics at play in this critical region,” Ogawa highlights. The researchers conclude that future catastrophic ruptures in this region could nucleate at the boundaries between weaker and stronger parts of the crust or at the edges of resistive zones.

Overall, this work will help earth scientists move closer to answering a pressing question for people in Türkiye, as Ogawa remarks: “Our results can be used to estimate the location and potential magnitude of future megathrust earthquakes, with significant implications for disaster prevention and mitigation.” Further research efforts will hopefully contribute to saving lives and minimizing the potential damage caused by the next large earthquake at the NAF.

 

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About Institute of Science Tokyo (Science Tokyo)
Institute of Science Tokyo (Science Tokyo) was established on October 1, 2024, following the merger between Tokyo Medical and Dental University (TMDU) and Tokyo Institute of Technology (Tokyo Tech), with the mission of “Advancing science and human wellbeing to create value for and with society.”

 

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Journal

Geology

DOI

10.1130/G52995.1 

Method of Research

Computational simulation/modeling

Subject of Research

Not applicable

Article Title

3-D electromagnetic imaging of highly deformed fluid-rich weak zones and locked section of the North Anatolian fault beneath the Marmara Sea

 

Research alert: Spreading drug costs over the year may ease financial burden for U.S. Medicare cancer patients

University of California - San Diego

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A new study examines the potential impact of the Medicare Prescription Payment Plan (M3P) — an opt-in policy implemented in 2025 under the Inflation Reduction Act that allows beneficiaries to spread out of pocket (OOP) costs over the calendar year — on Medicare Part D beneficiaries with cancer who face high out-of-pocket (OOP) prescription drug costs. Many cancer patients enrolled in Part D incur thousands of dollars in OOP expenses at the start of the year to quickly reach the catastrophic coverage threshold, after which cost-sharing drops to zero. For patients living on fixed or limited incomes, these large upfront payments can be unmanageable, contributing to delayed treatment initiation, medication nonadherence, financial distress and poorer health outcomes.

Using Medicare 2022 claims data from a national sample of beneficiaries with cancer, the researchers analyzed when patients typically reach the catastrophic cap and modeled how M3P could alter payment patterns. The analysis found that nearly half of Medicare Part D beneficiaries with cancer are projected to reach the annual OOP cap, with about one-third doing so as early as January 2025. Under current structures, this results in highly front-loaded costs. Enrollment in M3P — which allows beneficiaries to spread OOP payments evenly across the year — substantially reduced monthly payment volatility, particularly for those who reach catastrophic coverage early, and could help mitigate cost-related nonadherence.

Importantly, the study highlights that awareness and uptake of M3P remain extremely low, limiting its potential benefits. The Centers for Medicare and Medicaid Services (CMS) estimates that 2.4 million (6 %) of Part D beneficiaries could benefit from enrolling in M3P. Aryana Sepassi, PharmD, MAS, assistant professor of clinical pharmacy at the University of California San Diego Skaggs School of Pharmacy and Pharmaceutical Sciences and colleagues conclude that making the program automatic, rather than opt-in, could significantly expand its impact, reduce financial burden for vulnerable patients, and support more consistent adherence to life-sustaining cancer therapies.

The study was published Jan. 15, 2026, in the Journal of Clinical Oncology.

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Journal

Journal of Clinical Oncology

DOI

10.1200/JCO-25-01788 

 

The sky is full of secrets: Glaring vulnerabilities discovered in satellite communications

Texts, phone calls, military communication, internal corporate networks all easily eavesdropped on using off-the-shelf equipment

University of California - San Diego

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Aaron Schulman, left, and Nadia Heninger, professors in the UC San Diego Department of Computer Science and Engineering, led the research that uncovered vulnerabilities in satellite communications.

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Credit: David Baillot/UC San Diego Jacobs School of Engineering

With $800 of off-the-shelf equipment and months worth of patience, a team of U.S. computer scientists set out to find out how well geostationary satellite communications are encrypted. And what they found was shocking. 

Close to half of the communications beamed from satellites to the ground that the researchers were able to listen in on were not encrypted. This included sensitive data including cellular text messages, voice calls, as well as sensitive military information, data from internal corporate and bank networks, and the in-flight online activity of airline passengers. 

The research team, led by Aaron Schulman and Nadia Heninger, two computer science professors at the University of California San Diego, then set out to find out which companies and government agencies were failing to encrypt data in order to contact them and disclose the vulnerabilities.

In this study, researchers focused on geosynchronous (GEO) satellites, which orbit the Earth at a fixed altitude and position around the equator. 

“Given that any individual with a clear view of the sky and $800 can set up their own GEO interception station from Earth, one would expect that GEO satellite links carrying sensitive commercial and government network traffic would use standardized link and/or network layer encryption to prevent eavesdroppers,” the researchers write in a paper presented in October at the CCS 2025 conference in Taiwan.

“There has been a concerted effort over the past two decades to encrypt Web traffic because of widespread concern about government eavesdropping through tapping fiber-optic cables or placing equipment in Internet exchange points; it is shocking to discover that this traffic may simply be broadcast to a continent-sized satellite footprint,” the researchers also write. 

In several cases, the researchers’ findings led to immediate action. The team disclosed to T-Mobile that some of their satellite traffic was unencrypted and left text messages, user Internet traffic and the content of voice calls vulnerable to eavesdropping. The company then quickly enabled encryption. Other organizations including Walmart and KPU Telecom have also enabled encryption in response to the researchers’ findings. 

Communications from specific satellites

There are 590 geosynchronous satellites orbiting the earth, with a wide variety of uses, including residential television and Internet services, and in-flight WiFi. These satellites also carry traffic on private networks for sensitive, remote commercial and military equipment. By placing a large satellite dish on the top of the computer science and engineering building at the UC San Diego Jacobs School of Engineering, researchers were able to intercept communications from 39 satellites – about 15% of GEO satellites–during a seven-month period. 

GEO satellites are known to be potentially vulnerable to eavesdropping. As a result, a cottage industry has arisen to try to listen in on signals using off-the-shelf, commercially available satellite dishes. High-quality free software is available to receive satellite signals, as long as they’re not encrypted. A thriving online community of enthusiasts publishes open databases of satellite coordinates and transponders. As part of their study, researchers contributed new software that automates both scanning for satellites and decoding these signals.  

But until now, no one had tested on a large scale all the different types of satellite transmissions that can be eavesdropped on. The researchers believe their study is the most comprehensive to date of GEO satellites, their communications, levels of encryption and various communications equipment they carry. Many organizations don’t seem to realize that satellite traffic is not part of their internal network and can be captured if not encrypted, the researchers write. “There is a clear mismatch between how satellite customers expect data to be secured and how it is secured in practice," they said.  

Examples of vulnerabilities in U.S. communications systems

Researchers captured data from two companies that provide in-flight entertainment: Intelsat and Panasonic. They were able to determine which airlines and which flights the data was coming from, as well as metadata including which websites passengers were visiting. Researchers even were able to capture audio from news shows, sports and other programs passengers were watching in flight. 

In addition, other data the team decoded allowed them to find the names of vessels owned by the U.S. military together with both encrypted and unencrypted traffic from those vessels’ communication systems.

The vulnerability for cell phone communications, such as T-Mobile’s, happens when someone places a call in a remote area where the call is connected through a cell phone tower that routes  through a satellite, which then beams the call to the cellphone company. 

Phone calls can be encrypted at different levels. One layer of encryption comes into play from phone to cell phone tower and another from tower to tower. These last two layers get stripped away when a call gets transmitted via satellite, leaving the content of the call or text vulnerable if it’s not encrypted. The only way to protect call and text content is to encrypt that layer of data – this happens when making calls with Signal, or from iPhone to iPhone, for example. 

“Cell phone traffic is carefully encrypted [...] between phone and tower to protect it against local eavesdroppers; it is shocking to discover that these private conversations were then broadcast to large portions of the continent, and that these security issues were not limited to isolated mistakes,” the researchers write. 

Many vulnerabilities in Mexican communications systems

Many of the vulnerabilities researchers found came from companies and government agencies in Mexico. That is not surprising since many of the satellites researchers could reach transmit data to and from our neighbor to the south. 

Two Mexican telecommunications companies, TelMex and WiBo, were particularly vulnerable. For both WiBo and TelMex, the data included phone numbers for parties on both sides of a phone call, as well as unencrypted voice data that would enable full reconstruction of audio for phone calls. Also, the data included information about online smartphone activity, including, for example, using TikTok and accessing Apple iCloud or Samsung’s app store. 

Researchers observed unencrypted satellite traffic from many organizations within the Mexican government, including the military, law enforcement and other government agencies.  For example, researchers were able to see the locations of aircraft and ships, as well as their repair schedules. They were also able to see personnel records for law enforcement. 

In addition, network traffic for Walmart Mexico was also not protected, giving researchers access to a wide range of data, including unencrypted internal corporate emails. Sales data were also available.

“We observe significant amounts of highly sensitive internal network traffic being broadcast unencrypted to large portions of North America. The severity of our findings suggests that these organizations do not routinely monitor the security of their own satellite communication links,” the researchers write. 

They are now planning to look at different kinds of satellites and perhaps locate antennas in different parts of the continental United States to capture a different range of satellite communications. 

The research team released the software they used for this study on Github.
 

Don’t look up: There are sensitive internal links in the clear on GEO satellites

Wenyi Morty Zhang, Keegan Ryan, Nadia Heninger and Aaron Schulman, UC San Diego Department of Computer Science and Engineering

Annie Dai and Dave Levin, University of Maryland 

 

Coverage of GEO satellites from the research team's location on the UC San Diego campus. Each dot represents a unique GEO satellite. The green shaded region shows the theoretically achievable scanning area; pink highlights coverage enabled by precise alignment.

From left: Annie Dai, Aaron Schulman, Keegan Ryan, Nadia Heninger and Monty Zhang. Zhang, Schulman, Ryan and Heninger are from UC San Diego. Dai is from University of Maryland as is Dave Levin, not pictured. 

Courtesy University of California San Diego