Lifeboat Foundation

Combinatorial problems often arise in puzzles, origami, and metamaterial design. Such problems have rare collections of solutions that generate intricate and distinct boundaries in configuration space. Using standard statistical and numerical techniques, capturing these boundaries is often quite challenging. Is it possible to flatten a 3D origami piece without causing damage? This question is one such combinatorial issue. As each fold needs to be consistent with flattening, such results are difficult to predict simply by glancing at the design. To answer such questions, the UvA Institute of Physics and the research center AMOLF have shown that researchers may more effectively and precisely respond to such queries by using machine learning techniques.

Despite employing severely undersampled training sets, Convolutional Neural Networks (CNNs) can learn to distinguish these boundaries for metamaterials in minute detail. This raises the possibility of complex material design by indicating that the network infers the underlying combinatorial rules from the sparse training set. The research team thinks this will facilitate the development of sophisticated, functional metamaterials with artificial intelligence. The team’s recent study examined the accuracy of forecasting the characteristics of these combinatorial mechanical metamaterials using artificial intelligence. Their work has also been published in the Physical Review Letters publication.

The attributes of artificial materials, which are engineered materials, are governed by their geometrical structure rather than their chemical makeup. Origami is one such metamaterial. The capacity of an origami piece to flatten is governed by how it is folded, i.e., its structure, and not by the sort of paper it is made of. More generally, the clever design enables us to accurately regulate a metamaterial’s bending, buckling, or bulging. This can be used for many different things, from satellite solar panels that unfurl to shock absorbers.

For the past two centuries, humans have relied on fossil fuels for concentrated energy; hundreds of millions of years of photosynthesis packed into a convenient, energy-dense substance. But that supply is finite, and fossil fuel consumption has tremendous negative impact on Earth’s climate.

“The biggest challenge many people don’t realize is that even nature has no solution for the amount of energy we use,” said University of Chicago chemist Wenbin Lin. Not even photosynthesis is that good, he said: “We will have to do better than nature, and that’s scary.”

One possible option scientists are exploring is “artificial photosynthesis”—reworking a plant’s system to make our own kinds of fuels. However, the chemical equipment in a single leaf is incredibly complex, and not so easy to turn to our own purposes.

Organic photovoltaics, solar energy devices based on organic semiconductors, have so far achieved very promising results in experimental settings, both in terms of efficiency and stability. However, engineers have not yet devised reliable strategies to fabricate these devices on a large-scale at a reasonable cost.

Researchers at Wuhan University in China have recently identified an approach that could facilitate the rapid fabrication of photoactive layers for organic solar cells, without compromising the cells’ efficiency and stability. Their proposed strategy, introduced in a paper published in Nature Energy, is based on sequential deposition, a method often used to deposit organic semiconductors and perovskite films on substrates.

“To realize the commercialization of organic photovoltaics (OPVs), the golden triangle of power conversion efficiency (PCE), stability, and cost should be considered simultaneously,” Jie Min, one of the researchers who carried out the study, told TechXplore.

In 2021, researchers from Toyota Central R&D Labs developed a large, cost-effective artificial photosynthesis system that produces industrial formate at a solar-to-chemical conversion efficiency (ηSTC) of 10.5%¹. Researchers from the lab say that, to their knowlege, this ηSTC is a first for a one metre squared cell.

Within the next 10 years, the company aims to establish artificial photosynthesis technology for wide-scale production of useful carbon compounds.

Solar power gathered far away in space, seen here being transmitted wirelessly down to Earth to wherever it is needed. ESA plans to investigate key technologies needed to make Space-Based Solar Power a working reality through its SOLARIS initative. One such technology – wireless power transmission – was recently demonstrated in Germany to an audience of decision makers from business and government.

The demonstration took place at Airbus’ X-Works Innovation Factory in Munich. Using microwave beaming, green energy was transmitted green energy between two points representing ‘Space’ and ‘Earth’ over a distance of 36 metres.

The received power was used to light up a model city, produce green hydrogen by splitting water and even to produce the world’s first wirelessly cooled 0% alcohol beer in a fridge before serving to the watching audience.

Earth’s low orbit is filling up, meaning radiation-tolerant cell designs are required as satellites head to higher orbits. Will these new ones do?

Scientists have developed a radiation-tolerant photovoltaic cell design that features an ultrathin layer of light-absorbing material. According to a new study published today (Nov .08) in the Journal of Applied Physics by AIP Publishing.

Significantly, the ultra-thin solar cells not only surpass earlier suggested thicker solar cells in resilience to irradiation; they also produce the same amount of power from converted sunlight after 20 years of use. Additionally, the novel photovoltaic cells could reduce load and considerably lower launch expenses. Barthel.

One can split an atomic nucleus to produce energy, but can you also split water to create environment-friendly hydrogen fuel? Doing so currently has two drawbacks: It is both time and energy intensive.

But now, researchers at Ben-Gurion University of the Negev in Beersheba and the Technion-Israel Institute of Technology in Haifa have taken a different path. BGU environmental physicist Prof. Arik Yochelis and Technion materials science professor Avner Rothschild believe they have identified new pathways that would speed up the catalytic process they think will reduce the invested electrical energy costs significantly.

Their splitting process is assisted by solar energy, which is known scientifically by the term photoelectrochemistry, and lowers the amount of the invested electrical energy needed to break the chemical bonds in the water molecule to generate hydrogen and oxygen. Oxygen evolution – the process of generating molecular oxygen (O₂) by a chemical reaction, usually from water – requires the transfer of four electrons to create one oxygen molecule and then the adding of two hydrogen molecules to make water.

Solar cells that are stretchable, flexible and wearable won the day and the best poster award from a pool of 215 at Research Expo 2016 April 14 at the University of California San Diego. The winning nanoengineering researchers aim to manufacture small, flexible devices that can power watches, LEDs and wearable sensors. The ultimate goal is to design and build much bigger flexible solar cells that could be used as power sources and shelter in natural disasters and other emergencies.

Research Expo is an annual showcase of top graduate research projects for the Jacobs School of Engineering at UC San Diego. During the poster session, graduate students are judged on the quality of their work and how well they articulate the significance of their research to society. Judges from industry, who often are alumni, pick the winners for each department. A group of faculty judges picks the overall winner from the six department winners.

Continue reading “Stretchable, Flexible, Wearable Solar Cells Take Top Prize at Research Expo 2016” »

I live in Manitoba, a province of Canada where all but a tiny fraction of electricity is generated from the potential energy of water. Unlike in British Columbia and Quebec, where generation relies on huge dams, our dams on the Nelson River are low, with hydraulic heads of no more than 30 meters, which creates only small reservoirs. Of course, the potential is the product of mass, the gravitational constant, and height, but the dams’ modest height is readily compensated for by a large mass, as the mighty river flowing out of Lake Winnipeg continues its course to Hudson Bay.

You would think this is about as “green” as it can get, but in 2022 that would be a mistake. There is no end of gushing about China’s cheap solar panels—but when was the last time you saw a paean to hydroelectricity?

Construction of large dams began before World War II. The United States got the Grand Coulee on the Columbia River, the Hoover Dam on the Colorado, and the dams of the Tennessee Valley Authority. After the war, construction of large dams moved to the Soviet Union, Africa, South America (Brazil’s Itaipu, at its completion in 1984 the world’s largest dam, with 14 gigawatts capacity), and Asia, where it culminated in China’s unprecedented effort. China now has three of the world’s six largest hydroelectric stations: Three Gorges, 22.5 GW (the largest in the world); Xiluodu, 13.86 GW; and Wudongde, 10.2 GW. Baihetan on the Jinsha River should soon begin full-scale operation and become the world’s second-largest station (16 GW).