A research team led by Prof. Zhang Tianshu from the Hefei Institutes of Physical Science of the Chinese Academy of Sciences has developed a low-stress electro-optic switch based on large-aperture β-barium borate (BBO) slab crystals and integrated it into an Nd:YAG hybrid-cavity Innoslab laser system. Their study, published in Optics Express on January 13, addresses long-standing challenges in high-energy laser systems, particularly those related to switching modulation consistency and operational stability.
One type of friction can waste energy even when two perfectly smooth surfaces move against each other, but researchers are getting a handle on how to attenuate or stop it completely
Researchers have fabricated a hair-thin microphone made entirely of silica fiber that can detect a large range of ultrasound frequencies beyond the reach of the human ear. Able to withstand temperatures up to 1,000°C, the device could eventually be used inside high-voltage transformers to detect early signs of failure before power outages occur.
“Conventional electronic sensors often fail under thermal stress or suffer from severe signal interference,” said Xiaobei Zhang, a member of the research team from Shanghai University. “Our all-fiber microphone can survive in hazardous environments and is completely immune to electromagnetic interference while remaining sensitive enough to hear the subtle early warning signals of equipment failure.”
In an article published in Optics Express, the researchers describe their new microphone, which is sensitive to frequencies from 40 kHz to 1.6 MHz. Unlike traditional microphones that rely on bulky housing, the new microphone is entirely integrated within a fiber just 125 microns in diameter.
Wherever hydrogen is present, safety sensors are required to detect leaks and prevent the formation of flammable oxyhydrogen gas when hydrogen is mixed with air. It is therefore a challenge that today’s sensors do not work optimally in humid environments—because where there is hydrogen, there is very often humidity. Now, researchers at Chalmers University of Technology, Sweden, are presenting a new sensor that is well suited to humid environments—and actually performs better the more humid it gets.
“The performance of a hydrogen gas sensor can vary dramatically from environment to environment, and humidity is an important factor. An issue today is that many sensors become slower or perform less effectively in humid environments. When we tested our new sensor concept, we discovered that the more we increased the humidity, the stronger the response to hydrogen became. It took us a while to really understand how this could be possible,” says Chalmers doctoral student Athanasios Theodoridis, who is the lead author of the article published in the journal ACS Sensors.
Hydrogen is an increasingly important energy carrier in the transport sector and is used as a raw material in the chemical industry or for green steel manufacturing. In addition to water being constantly present in ambient air, it is also formed when hydrogen reacts with oxygen to generate energy, for example, in a fuel cell that can be used in hydrogen-powered vehicles and ships. Furthermore, fuel cells themselves require water to prevent the membranes that separate oxygen and hydrogen inside them from drying out.
Japan and California have embraced hydrogen fuel-cell technologies, a form of renewable energy that can be used in vehicles and for supplying clean energy to manufacturing sectors. But the technology remains expensive due to its reliance on precious metals such as platinum. Engineers at Washington University in St. Louis are working on this challenge, finding ways to stabilize ubiquitous iron components for use in fuel cells to replace the expensive platinum metals, which would make hydrogen fuel-cell vehicles more affordable.
Cost challenges for fuel-cell vehicles
“The hydrogen fuel cell has been successfully commercialized in Japan and California in the U.S.,” said Gang Wu, a professor of energy, environmental and chemical engineering at the McKelvey School of Engineering. “But these vehicles struggle to compete with the battery vehicle and combustion engine vehicle, with cost being the main issue.”
Scientists say a real warp drive may no longer be pure science fiction, thanks to new breakthroughs in theoretical physics. Recent studies suggest space itself could be compressed and expanded, allowing faster-than-light travel without breaking known laws of physics. Unlike sci-fi engines, this concept wouldn’t move a ship through space — it would move space around the ship. Researchers are now exploring how energy, gravity, and exotic matter could make this possible. In this video, we explain how a warp drive could work and how close science really is.
The company is already the world’s largest battery maker, supplying cells to major automakers. With this latest development, the battery giant is positioning itself at the center of the race to deliver gasoline-like convenience without sacrificing durability.
The core challenge engineers set out to address was whether an EV battery could withstand repeated ultra-fast charging without rapid degradation. A 5C charge rate means an 80-kilowatt-hour battery pack could theoretically accept around 400 kilowatts of power. That level of charging can refill a battery in roughly 12 minutes, similar to a typical gas stop.
Fast charging has long been associated with faster wear. The engineers tested whether the chemistry could handle that stress over time. According to the company, the answer was yes. Under standard conditions at 68°F, the battery retained at least 80 percent of its original capacity after 3,000 full charge-and-discharge cycles.
For the first time, physicists in China have virtually eliminated the friction felt between two surfaces at scales visible to the naked eye. In demonstrating “structural superlubricity,” the team, led by Quanshui Zheng at Tsinghua University, have resolved a long-standing debate surrounding the possibility of the effect. Published in Physical Review Letters, the result could potentially lead to promising new advances in engineering.
When two objects slide over each other, any roughness on their surfaces will almost inevitably resist the motion, creating the force of friction. Yet in 2004, physicists showed that friction can be virtually eliminated between two graphite surfaces, simply by rotating their respective molecular structures.
Named structural superlubricity (SSL), the effect is highly desired by engineers; in principle, allowing them to eliminate wear on both surfaces and minimize energy lost as waste heat.
