A team of scientists at Linköping University in Sweden has made a groundbreaking discovery in the production of green hydrogen, a promising renewable energy source. By developing a new triple-layer material, they have supercharged the energy yield by an impressive 800%.

Hydrogen produced from water is becoming increasingly important as the world shifts away from fossil fuels. The EU plans to ban new petrol and diesel car sales by 2035, making electric motors more common in vehicles. However, heavy trucks, ships, and aircraft require alternative energy sources, where hydrogen comes into play.

The researchers have previously shown that cubic silicon carbide (3C-SiC) has beneficial properties for facilitating the reaction where water is split into hydrogen and oxygen. Now, they’ve further developed a combined material consisting of three layers: a layer of 3C-SiC, a layer of cobalt oxide, and a catalyst material that helps to split water.

The new material, known as Ni(OH)2/Co3O4/3C-SiC, has demonstrated eight times better performance than pure cubic silicon carbide for splitting water into hydrogen. When sunlight hits the material, electric charges are generated, which are then used to split water. By combining the three layers, the researchers have improved the ability to separate positive and negative charges, making the splitting of water more effective.

The distinction between “grey” and “green” hydrogen is crucial in this context. Almost all hydrogen present on the market is “grey” hydrogen produced from fossil fuels, with significant environmental consequences. In contrast, “green” hydrogen is produced using renewable electricity as a source of energy.

Linköping University researchers aim to utilize only solar energy to drive the photochemical reaction to produce “green” hydrogen. Currently, materials under development have an efficiency of between 1 and 3 per cent, but for commercialization, the target is 10% efficiency. The research team estimates that it may take around five to ten years to develop materials that reach this coveted limit.

The study has been funded by several organizations, including the Swedish Foundation for International Cooperation in Research and Higher Education (STINT), the Olle Engkvists Stiftelse, the ÅForsk Foundation, the Carl Tryggers Stiftelse, and through the Swedish Government Strategic Research Area in Advanced Functional Materials (AFM) at Linköping University.

This breakthrough has the potential to significantly impact the renewable energy landscape, making green hydrogen production more efficient and cost-effective. As researchers continue to push the boundaries of this technology, we can expect even more exciting developments in the future.

The increasing number of electric vehicles on roads has led to concerns about their safety signals. A recent study from Chalmers University of Technology in Sweden has found that one of the most common signal types is difficult for humans to locate, especially when multiple similar vehicles are moving simultaneously.

Researchers conducted a study involving 52 test subjects who were placed at the center of anechoic chambers and surrounded by loudspeakers. Three types of simulated vehicle sounds were played on the loudspeakers, corresponding to signals from one, two or more electric and hybrid vehicles, plus an internal combustion engine. The test subjects had to mark the direction they thought the sound was coming from as quickly as possible.

The results showed that all signal types were harder to locate than the sound of an internal combustion engine. One type of signal, which consisted of two tones, was particularly difficult for the test subjects to distinguish, with many unable to determine whether it was one or multiple vehicles emitting the sound.

This study highlights a hidden flaw in electric vehicle safety and emphasizes the need for further research into how people react in traffic situations involving electric vehicles. The researchers suggest that new signal types may be needed to improve detection and localization, while minimizing negative impacts on non-road users.

The study’s findings have implications for policymakers and car manufacturers, who must balance the need for effective safety signals with the potential consequences of noisy environments.

As the number of electric vehicles on roads continues to grow, it is essential that safety considerations are prioritized. This study serves as a reminder of the importance of continued research into the acoustic properties of electric vehicle safety signals.

The University of Michigan has developed a groundbreaking prototype that could revolutionize the way we design and navigate underwater vehicles. By taking inspiration from the humble golf ball, researchers have created a spherical prototype with adjustable surface dimples that can drastically reduce drag while eliminating the need for protruding appendages like fins or rudders.

Anchal Sareen, U-M assistant professor of naval architecture and marine engineering, led the research team in developing the smart morphable sphere. The team formed the prototype by stretching a thin layer of latex over a hollow sphere dotted with holes, resembling a pickleball. A vacuum pump depressurizes the core, pulling the latex inwards to create precise dimples when switched on.

To test how the dimples affected drag, the sphere was put through its paces within a 3-meter-long wind tunnel. The researchers found that for high wind speeds, shallower dimples cut the drag more effectively while deeper dimples were more efficient at lower wind speeds. By adjusting dimple depth, the sphere reduced drag by 50% compared to a smooth counterpart for all conditions.

Moreover, the adaptive skin setup was able to notice changes in the speed of the incoming air and adjust dimples accordingly to maintain drag reductions. This concept could be applied to underwater vehicles, reducing both drag and fuel consumption.

The smart morphable sphere can also generate lift, allowing for controlled movement. By designing the inner skeleton with holes on only one side, the researchers created asymmetric flow separation on the two sides of the sphere, deflecting the wake toward the smooth side. This effectively pushed the sphere in the direction of the dimples, enabling precise steering by selectively activating dimples on the desired side.

The team tested the new sphere in the same wind tunnel setup with varying wind velocity and dimple depth. With the optimal dimple depth, the half rough/half smooth sphere generated lift forces up to 80% of the drag force. This is comparable to the Magnus effect, but instead of using rotation, it was created entirely by modifying the surface texture.

The implications of this research are vast and exciting. For example, compact spherical robotic submarines that prioritize maneuverability over speed for exploration and inspection could benefit from this mechanism, reducing the need for multiple propulsion systems.

Anchal Sareen anticipates collaborations that combine expertise in materials science and soft robotics, further advancing the capabilities of this dynamic skin technology. She believes that this smart dynamic skin technology could be a game-changer for unmanned aerial and underwater vehicles, offering a lightweight, energy-efficient, and highly responsive alternative to traditional jointed control surfaces.

Ultimately, this innovation promises to enhance maneuverability, optimize performance, and unlock new possibilities for vehicle design. As researchers continue to explore and refine this technology, we can expect to see significant advancements in the field of underwater vehicles and beyond.