Lifeboat Foundation

The mounds that certain species of termites build above their nests have long been considered to be a kind of built-in natural climate control—an approach that has intrigued architects and engineers keen to design greener, more energy-efficient buildings mimicking those principles. There have been decades of research devoted to modeling just how these mounds function. A new paper published in the journal Frontiers in Materials offers new evidence favoring an integrated-system model in which the mound, the nest, and its tunnels function together much like a lung.

Perhaps the most famous example of the influence of termite mounds in architecture is the Eastgate Building in Harare, Zimbabwe. It is the country’s largest commercial and shopping complex, and yet it uses less than 10 percent of the energy consumed by a conventional building of its size because there is no central air conditioning and only a minimal heating system. Architect Mick Pearce famously based his design in the 1990s on the cooling and heating principles used in the region’s termite mounds, which serve as fungus farms for the termites. Fungus is their primary food source.

Conditions have to be just right for the fungus to flourish. So the termites must maintain a constant temperature of 87° F in an environment where the outdoor temperatures range from 35° F at night to 104° F during the day. Biologists have long suggested that they do this by constructing a series of heating and cooling vents throughout their mounds, which can be opened and closed during the day to keep the temperature inside constant. The Eastgate Building relies on a similar system of well-placed vents and solar panels.

The ability to produce more electricity per weight compared to traditional silicon solar cells makes them highly suitable for sending into space to harvest the Sun’s energy, according to the researchers.

“High specific power is actually one of the greatest goals of any space-based light harvesting or energy harvesting technology,” said Deep Jariwala from the University of Pennsylvania.

“This is not just important for satellites or space stations, but also if you want real utility-scale solar power in space. The number of [silicon] solar cells you would have to ship up is so large that no space vehicles currently can take those kinds of materials up there in an economically viable way.”

Solar power is the fastest-growing form of renewable energy and currently accounts for 3.6% of global electricity production today. This makes it the third largest source of the renewable energy market, followed by hydroelectric power and wind. These three methods are expected to grow exponentially in the coming decades, reaching 40% by 2035 and 45% by 2050. Altogether, renewables are expected to account for 90% of the energy market by mid-century, with solar accounting for roughly half. However, several technical challenges and issues need to be overcome for this transition to occur.

The main limiting factor for solar power is intermittency, meaning it can only collect power when sufficient sunlight is available. To address this, scientists have spent decades researching space-based solar power (SBSP), where satellites in orbit would collect power 24 hours a day, 365 days a year, without interruption. To develop the technology, researchers with the Space Solar Power Project (SSPP) at Caltech recently completed the first successful wireless power transfer using the Microwave Array for Power-transfer Low-orbit Experiment (MAPLE).

Continue reading “New Satellite Successfully Beams Power From Space” »

A novel 3D printing method called high-throughput combinatorial printing (HTCP) has been created that significantly accelerates the discovery and production of new materials.

The process involves mixing multiple aerosolized nanomaterial inks during printing, which allows for fine control over the printed materials’ architecture and local compositions. This method produces materials with gradient compositions and properties and can be applied to a wide range of substances including metals, semiconductors.

Semiconductors are a type of material that has electrical conductivity between that of a conductor (such as copper) and an insulator (such as rubber). Semiconductors are used in a wide range of electronic devices, including transistors, diodes, solar cells, and integrated circuits. The electrical conductivity of a semiconductor can be controlled by adding impurities to the material through a process called doping. Silicon is the most widely used material for semiconductor devices, but other materials such as gallium arsenide and indium phosphide are also used in certain applications.

Caltech’s recent breakthrough has moved us closer to achieving the transformative potential of space-based solar power.

The mammalian retina is a complex system consisting out of cones (for color) and rods (for peripheral monochrome) that provide the raw image data which is then processed into successive layers of neurons before this preprocessed data is sent via the optical nerve to the brain’s visual cortex. In order to emulate this system as closely as possible, researchers at Penn State University have created a system that uses perovskite (methylammonium lead bromide, MAPbX₃) RGB photodetectors and a neuromorphic processing algorithm that performs similar processing as the biological retina.

Panchromatic imaging is defined as being ‘sensitive to light of all colors in the visible spectrum’, which in imaging means enhancing the monochromatic (e.g. RGB) channels using panchromatic (intensity, not frequency) data. For the retina this means that the incoming light is not merely used to determine the separate colors, but also the intensity, which is what underlies the wide dynamic range of the Mark I eyeball. In this experiment, layers of these MAPbX₃ (X being Cl, Br, I or combination thereof) perovskites formed stacked RGB sensors.

The output of these sensor layers was then processed in a pretrained convolutional neural network, to generate the final, panchromatic image which could then be used for a wide range of purposes. Some applications noted by the researchers include new types of digital cameras, as well as artificial retinas, limited mostly by how well the perovskite layers scale in resolution, and their longevity, which is a long-standing issue with perovskites. Another possibility raised is that of powering at least part of the system using the energy collected by the perovskite layers, akin to proposed perovskite-based solar panels.

Researchers not only want to further develop printable solar cells technologically. Rather, they want to provide solutions with them in order to implement different application variants.

Scientists say they’ve successfully transmitted solar energy gathered in orbit down to the Earth’s surface.

The flexible silicon solar cell could find use in places where more expensive solar cells might have been favoured.

A new technique for producing silicon solar cells that are more than 24% efficient and yet can be rolled up like a sheet of paper has been demonstrated. The work could allow solar cells to be used in applications that currently use more expensive thin-film alternatives.