Bacteriophages or “phages” is the terms used for viruses that infect bacteria. The UAB researchers, led by Terje Dokland, Ph.D., in collaboration with Asma Hatoum-Aslan, Ph.D., at the University of Illinois Urbana-Champaign, have described atomic models for all or part of 11 different structural proteins in phage Andhra. The study is published in Science Advances.

Andhra is a member of the picovirus group. Its host range is limited to S. epidermidis. This skin bacterium is mostly benign but also is a leading cause of infections of indwelling medical devices. “Picoviruses are rarely found in phage collections and remain understudied and underused for therapeutic applications,” said Hatoum-Aslan, a phage biologist at the University of Illinois.

With emergence of antibiotic resistance in S. epidermidis and the related pathogen Staphylococcus aureus, researchers have renewed interest in potentially using bacteriophages to treat bacterial infections. Picoviruses always kill the cells they infect, after binding to the bacterial cell wall, enzymatically breaking through that wall, penetrating the cell membrane and injecting viral DNA into the cell. They also have other traits that make them attractive candidates for therapeutic use, including a small genome and an inability to transfer bacterial genes between bacteria.

Knowledge of protein structure in Andhra and understanding of how those structures allow the virus to infect a bacterium will make it possible to produce custom-made phages tailored to a specific purpose, using genetic manipulation.

“The structural basis for host specificity between phages that infect S. aureus and S. epidermidis is still poorly understood,” said Dokland, a professor of microbiology at UAB and director of the UAB Cryo-Electron Microscopy Core. “With the present study, we have gained a better understanding of the structures and functions of the Andhra gene products and the determinants of host specificity, paving the way for a more rational design of custom phages for therapeutic applications. Our findings elucidate critical features for virion assembly, host recognition and penetration.”

Staphylococcal phages typically have a narrow range of bacteria they can infect, depending on the variable polymers of wall teichoic acid on the surface of different bacterial strains. “This narrow host range is a double-edged sword: On one hand, it allows the phages to target only the specific pathogen causing the disease; on the other hand, it means that the phage may need to be tailored to the patient in each specific case,” Dokland said.

The general structure of Andhra is a 20-faced, roundish icosahedral capsid head that contains the viral genome. The capsid is attached to a short tail. The tail is largely responsible for binding to S. epidermidis and enzymatically breaking the cell wall. The viral DNA is injected into the bacterium through the tail. Segments of the tail include the portal from the capsid to the tail, and the stem, appendages, knob and tail tip.

The 11 different proteins that make up each virus particle are found in multiple copies that assemble together. For instance, the capsid is made of 235 copies each of two proteins, and the other nine virion proteins have copy numbers from two to 72. In total, the virion is made up of 645 protein pieces that include two copies of a 12th protein, whose structure was predicted using the protein structure prediction program AlphaFold.

The atomic models described by Dokland, Hatoum-Aslan, and co-first authors N’Toia C. Hawkins, Ph.D., and James L. Kizziah, Ph.D., UAB Department of Microbiology, show the structures for each protein — as described in molecular language like alpha-helix, beta-helix, beta-strand, beta-barrel or beta-prism. The researchers have described how each protein binds to other copies of that same protein type, such as to make up the hexameric and pentameric faces of the capsid, as well as how each protein interacts with adjacent different protein types.

Electron microscopes use a beam of accelerated electrons to illuminate an object, providing much higher resolution than a light microscope. Cryo-electron microscopy adds the element of super-cold temperatures, making it particularly useful for near-atomic structure resolution of larger proteins, membrane proteins or lipid-containing samples like membrane-bound receptors, and complexes of several biomolecules together.

In the past eight years, new electron detectors have created a tremendous jump in resolution for cryo-electron microscopy over normal electron microscopy. Key elements of this so-called “resolution revolution” for cryo-electron microscopy are:

• Flash-freezing aqueous samples in liquid ethane cooled to below -256 degrees F. Instead of ice crystals that disrupt samples and scatter the electron beam, the water freezes to a window-like “vitreous ice.”
• The sample is kept at super-cold temperatures in the microscope, and a low dose of electrons is used to avoid damage to the proteins.
• Extremely fast direct electron detectors are able to count individual atoms at hundreds of frames per second, allowing sample movement to be corrected on the fly.
• Advanced computing merges thousands of images to generate three-dimensional structures at high resolution. Graphics processing units are used to churn through terabytes of data.
• The microscope stage that holds the sample can also be tilted as images are taken, allowing construction of a three-dimensional tomographic image, similar to a CT scan at the hospital.

The analysis of Andhra virion structure by the UAB researchers started with 230,714 particle images. Molecular reconstruction of the capsid, tail, distal tail and tail tip started with 186,542, 159,489, 159,489 and 159,489 images, respectively. Resolution ranged from 3.50 to 4.90 angstroms.

A satellite built for NASA and the French space agency Centre National d’Études Spatiales (CNES) to observe nearly all the water on our planet’s surface lifted off on its way to low-Earth orbit at 3:46 a.m. PST on Friday. The Surface Water and Ocean Topography (SWOT) spacecraft also has contributions from the Canadian Space Agency (CSA) and the UK Space Agency.

The Surface Water and Ocean Topography (SWOT) spacecraft launched atop a SpaceX rocket from Space Launch Complex 4E at Vandenberg Space Force Base in California with a prime mission of three years. The satellite will measure the height of water in freshwater bodies and the ocean on more than 90% of Earth’s surface. This information will provide insights into how the ocean influences climate change; how a warming world affects lakes, rivers, and reservoirs; and how communities can better prepare for disasters, such as floods.

After SWOT separated from the second stage of a SpaceX Falcon 9 rocket, ground controllers successfully acquired the satellite’s signal. Initial telemetry reports showed the spacecraft in good health. SWOT will now undergo a series of checks and calibrations before it starts collecting science data in about six months.

“Warming seas, extreme weather, more severe wildfires – these are only some of the consequences humanity is facing due to climate change,” said NASA Administrator Bill Nelson. “The climate crisis requires an all-hands-on-deck approach, and SWOT is the realization of a long-standing international partnership that will ultimately better equip communities so that they can face these challenges.”

SWOT will cover the entire Earth’s surface between 78 degrees south and 78 degrees north latitude at least once every 21 days, sending back about one terabyte of unprocessed data per day. The scientific heart of the spacecraft is an innovative instrument called the Ka-band radar interferometer (KaRIn), which marks a major technological advance. KaRIn bounces radar pulses off the water’s surface and receives the return signal using two antennas on either side of the spacecraft. This arrangement – one signal, two antennas – will enable engineers to precisely determine the height of the water’s surface across two swaths at a time, each of them 30 miles (50 kilometers) wide.

“We’re eager to see SWOT in action,” said Karen St. Germain, NASA Earth Science Division director. “This satellite embodies how we are improving life on Earth through science and technological innovations. The data that innovation will provide is essential to better understanding how Earth’s air, water, and ecosystems interact – and how people can thrive on our changing planet.”

Among the many benefits the SWOT mission will provide is a significantly clearer picture of Earth’s freshwater bodies. It will provide data on more than 95% of the world’s lakes larger than 15 acres (62,500 square meters) and rivers wider than 330 feet (100 meters) across. Currently, freshwater researchers have reliable measurements for only a few thousand lakes around the world. SWOT will push that number into the millions.

Along the coast, SWOT will provide information on sea level, filling in observational gaps in areas that don’t have tide gauges or other instruments that measure sea surface height. Over time, that data can help researchers better track sea level rise, which will directly impact communities and coastal ecosystems.

Such an ambitious mission is possible because of NASA’s long-standing commitment to working with agencies around the world to study Earth and its climate. NASA and CNES have built upon a decades-long relationship that started in the 1980s to monitor Earth’s oceans. This collaboration pioneered the use of a space-based instrument called an altimeter to study sea level with the launch of the TOPEX/Poseidon satellite in 1992.

“This mission marks the continuity of 30 years of collaboration between NASA and CNES in altimetry,” said Caroline Laurent, CNES Orbital Systems and Applications director. “It shows how international collaboration can be achieved through a breakthrough mission that will help us better understand climate change and its effects around the world.”

SWOT measurements will also help researchers, policymakers, and resource managers better assess and plan for things, including floods and droughts. By providing information on where the water is – where it’s coming from and where it’s going – researchers can improve flood projections for rivers and monitor drought effects on lakes and reservoirs.

“SWOT will provide vital information, given the urgent challenges posed by climate change and sea level rise,” said Laurie Leshin, NASA’s Jet Propulsion Laboratory director. JPL developed the KaRIn instrument and manages the U.S. portion of the mission. “That SWOT will fill gaps in our knowledge and inform future action is the direct result of commitment, innovation, and collaboration going back many years. We’re excited to get SWOT science underway.”

More Mission Information

JPL, which is managed for NASA by Caltech in Pasadena, California, leads the U.S. component of the project. For the flight system payload, NASA is providing the KaRIn instrument, a GPS science receiver, a laser retroreflector, a two-beam microwave radiometer, and NASA instrument operations. CNES is providing the Doppler Orbitography and Radioposition Integrated by Satellite (DORIS) system, the dual frequency Poseidon altimeter (developed by Thales Alenia Space), the KaRIn radio-frequency subsystem (together with Thales Alenia Space and with support from the UK Space Agency), the satellite platform, and ground control segment. CSA is providing the KaRIn high-power transmitter assembly. NASA is providing the launch vehicle and the agency’s Launch Services Program, based at Kennedy Space Center, is managing the associated launch services.

To learn more about SWOT, visit:

https://www.nasa.gov/swot

News Media Contacts

Tylar Greene

NASA Headquarters, Washington

202-358-0030

[email protected]

Jane J. Lee / Andrew Wang

Jet Propulsion Laboratory, Pasadena, Calif.

818-354-0307 / 626-379-6874

[email protected] / [email protected]

Leejay Lockhart / Laura Aguiar

Kennedy Space Center, Fla.

321-747-8310 / 321-593-6245

[email protected] / [email protected]

A group led by scientists at Michigan State University (MSU) have devised a way to track and measure the true picture of how one of the world’s most-traded commodities moves from the water to the plate within a country. Their findings in Nature Food about sub-Saharan Africa revealed surprising gaps in the traditional supply-and-demand analysis of fish and opens opportunities to get the right fish to those who need it most.

And the innovations they deployed, they say, can be useful anywhere.

“We know that all fish aren’t created equal in terms of containing the right nutrition for certain people in certain circumstances,” said co-author Abigail Bennett, assistant professor at MSU. “Effective policy needs new data that that reveals how variation in the supply, price, and form of fish in different places throughout a country shapes who can access that fish, with special attention to people who are poor and vulnerable to malnourishment.”

Existing data on food production indicate food supply, but not whether food reaches those who need it. Meanwhile, consumption data describe who ultimately ends up accessing food, but not where it came from or how it reached them. The group bridged that gap by looking at how fish moves across space through value chains after it is harvested and at household demographics.

They studied in Malawi in sub-Saharan Africa, looking at the trips two freshwater fish — small sardine-like usipa and medium-sized chambo, a variety of tilapia — took to end up at peoples’ tables, which meant understanding why fish ended up at certain markets, and whether people could afford them.

The little usipa is the bigger catch, both in volume and dollar value. It’s affordable, often sun-dried and consumed whole. Chambo is usually eaten fresh and is pricier.

The team, led by co-author Park Muhonda when he was a postdoctoral researcher at MSU, surveyed more than 900 people throughout the fish food journey. He now is at Oregon State University.

The group found that usipa is distributed much more widely than chambo — available in 72 or the 79 markets surveyed across Malawi — while chambo was available in only 16 of those markets, which skewed to urban areas. Usipa also packs more nutritional punch than chambo, being higher in protein, vitamins, and minerals critical to nursing women and their children.

But the group found that policies were championing the fancier chambo.

“While most fisheries policy in Malawi has previously focused on the larger high-value tilapia species, these results indicate the need for a shift in policy focus towards the small pelagic species to better support food security and nutrition,” said co-author Edith Gondwe, an MSU PhD student in fisheries and wildlife.

The work in “Spatial analysis of aquatic food access can inform nutrition-sensitive policy,” which revealed disconnects between policy and need, can help guide policy beyond Malawi.

“Our work on spatial analysis of fish in Malawi goes beyond Malawi and fish food systems,” said master’s student Emma Rice. “Most countries, including the United States, face food and nutrition security issues in different forms and contexts. This approach of spatial analysis of food systems could be adopted in any context to understand what types of food flow to which populations and through what mechanisms.”

Bennett, Gondwe, Rice and Muhonda are members of MSU’s Center for Systems Integration and Sustainability, as is co-author Dana Infante.

The paper authored also was authored by Emmanuel Kaunda, Sam Katengeza, Saweda Liverpool-Tasie, Ben Belton, Jared Ross and John Virdin. The work was funded by the Michigan State University Alliance for African Partnership.

EMIT media reel

EMIT fact sheet

Video of EMIT launch and first-light

Methane ‘Super-Emitters’ Mapped by NASA’s New Earth Space Mission

Observations from the Earth Surface Mineral Dust Source Investigation (EMIT) and other NASA science instruments will be part of a global survey of point-source emissions of methane from solid waste sites such as landfills. The multiyear effort is being developed and conducted by the nonprofit Carbon Mapper organization.

Methane is a potent greenhouse gas, the source of roughly a quarter to a third of global warming caused by humans. The aim of the new initiative is to establish a baseline assessment of global waste sites that emit methane at high rates. This information can support decision-makers as they work to reduce the concentration of the gas in the atmosphere and limit climate change.

Methane produced by the waste sector contributes an estimated 20% of human-caused methane emissions. Ton for ton, methane is more than 80 times more potent than carbon dioxide in trapping heat in the atmosphere. But where carbon dioxide remains in the air for centuries, methane has an atmospheric lifetime of only about a decade or two. That means some immediate slowing of atmospheric warming could be achieved if methane emissions were significantly reduced.

“Currently, there is limited actionable information about methane emissions from the global waste sector. A comprehensive understanding of high-emission point sources from waste sites is a critical step to mitigating them,” said Carbon Mapper CEO Riley Duren. “New technological capabilities that are making these emissions visible – and therefore actionable – have the potential to change the game, elevating our collective understanding of near-term opportunities in this often overlooked sector.”

Carbon Mapper received a grant from the Grantham Foundation for the Protection of the Environment to support its operations related to the waste-site initiative, including potential funding to cover airborne methane surveys using NASA airborne assets. The project will entail conducting an initial remote-sensing survey in 2023 of more than 1,000 managed landfills across the United States and Canada, and in key locations in Latin America, Africa, and Asia. To collect data from these regions, researchers will use aircraft-based sensors, including the Airborne Visible/Infrared Imaging Spectrometer-Next Generation (AVIRIS-NG), which was developed at NASA’s Jet Propulsion Laboratory in Southern California. In addition, they will use Arizona State University’s Global Airborne Observatory from the Center of Global Discovery and Conservation Science, which uses another JPL-built imaging spectrometer.

As part of the Carbon Mapper project, researchers will analyze methane data from EMIT as well. The JPL-managed imaging spectrometer was installed on the International Space Station in July 2022 to measure the mineral content at the surface of Earth’s major dust-producing regions.

In October, scientists demonstrated that EMIT can also identify methane plumes from “super-emitters.” In so doing, the team added another tool to help with NASA’s broader efforts to monitor greenhouse gases.

“NASA JPL has a decadelong track record of using airborne imaging spectrometers to make high-quality observations of methane point-source emissions,” said Robert Green, EMIT’s principal investigator at JPL. “With EMIT we have employed the same technology in a spaceborne instrument, enabling us to collect information on localized methane sources from orbit.”

After the first year of the Carbon Mapper project, researchers will conduct a broader survey of more than 10,000 landfills around the world using two satellites in the Carbon Mapper satellite program. The pair of spacecraft will be equipped with imaging spectrometer technology developed at JPL. The team is targeting a launch in late 2023 in coordination with Planet Labs PBC, among other partners.

Data from the project will be accessible at the Carbon Mapper Data Portal.

For additional details about EMIT, visit:

https://earth.jpl.nasa.gov/emit/

More About the Missions

EMIT was selected from the Earth Venture Instrument-4 solicitation under the Earth Science Division of NASA’s Science Mission Directorate and was developed at NASA’s Jet Propulsion Laboratory, which is managed for the agency by Caltech in Pasadena, California. The instrument’s data will be delivered to the NASA Land Processes Distributed Active Archive Center (DAAC) for use by other researchers and the public.

The Airborne Visible/Infrared Imaging Spectrometer-Next Generation (AVIRIS-NG) was built at JPL and designed to measure wavelengths of light from 380 to 2,510 nanometers. It has flown numerous missions, studying phenomena such as plant ecology, mineralogy, snow and ice hydrology, and environmental hazards.

Carbon Mapper is a nonprofit organization focused on facilitating timely action to mitigate greenhouse gas emissions. Its mission is to fill gaps in the emerging global ecosystem of methane and carbon dioxide monitoring systems by delivering data at facility scale that is precise, timely, and accessible to empower science-based decision making and action. The organization is leading the development of the Carbon Mapper constellation of satellites supported by a public-private partnership composed of Planet Labs PBC, JPL, the California Air Resources Board, the University of Arizona, Arizona State University, and RMI, with funding from High Tide Foundation, Bloomberg Philanthropies, Grantham Foundation for the Protection of the Environment, and other philanthropic donors.

News Media Contacts

Andrew Wang / Jane J. Lee

Jet Propulsion Laboratory, Pasadena, Calif.

626-379-6874 / 818-354-0307

[email protected] / [email protected]

Kelly Vaughn

Carbon Mapper, Pasadena, Calif.

970-401-0001

[email protected]

Young people are experiencing climate change to a greater extent than any previous generation. It’s hard to imagine what the climate will be like when they are senior adults. Although this is a very daunting topic, the adults of tomorrow must understand climate change causes, challenges, and solutions. Fortunately, there are numerous children’s books exploring the topic. If you’re looking for an informative gift for your young bookworm, you might consider an age-appropriate book about climate change.

Children’s books are an excellent way not just to impart knowledge but foster a reverence for the natural world and ultimately encourage protecting it. Overwhelming children with information about climate change issues without presenting solutions can create anxiety and resignation, so it is a balancing act. Here are some of our favorites on the topic that impart knowledge but not despair, while exploring positive actions.

Earth911 teams up with affiliate marketing partners to help fund our Recycling Directory. If you purchase an item through one of the affiliate links in this post, we will receive a small commission.

Energy Island: How One Community Harnessed the Wind and Changed Their World

Written and illustrated by Allan Drummond
Ages: Elementary school

This is an inspiring tale of how a windy island in Denmark harnessed the wind to become largely energy independent and reduced its carbon emissions by 140%. This narrative tale includes sidebars with background information on the problems with fossil fuels, climate change, and how wind energy works. The upbeat illustrations show people working together to find solutions and briefly explore solar energy, electric vehicles, biomass, and biofuels.

Eyewitness Climate Change – DK Witness

Ages: Late elementary to middle school

This book presents a solid overview of the climate, both past and present, and the impacts of climate change. It has many photos and illustrations and presents a nice overview of numerous issues, including disease, food production, water resources, and who is most vulnerable to the impacts of climate change. The book concludes with positive actions on how to cut carbon emissions through green transportation, energy efficiency, nuclear power, and renewable energy.

The Lonely Polar Bear

Written and illustrated by Khoa Le
Ages: Preschool to early elementary school

This lovely book is about a polar bear that wakes up alone and meets a mysterious little girl and animal friends. The touching tale by a talented Vietnamese author introduces young children to the concept of climate change in a gentle manner and with gorgeous illustrations. Although the story is about habitat loss in the fragile Artic in a general sense, it doesn’t examine the science of climate change.

Our World Out of Balance: Understanding Climate Change and What We Can Do

By Andrea Minoglio, illustrated by Laura Fanelli
Ages: Mid-elementary to early middle school

Well-written and beautifully illustrated, this book is an excellent introduction to climate change and other environmental issues facing the planet, including air pollution, rising sea levels, coral reef health, and wildfires. It is concisely written and helps instill a sense of wonder for earth’s ecosystems and how to work together to protect them.

Rebel Girls Climate Warriors: 25 Tales of Women Who Protect the Earth

Ages: Elementary and early middle school

This colorful book spotlights inspiring women conservationists, activists, authors, and philanthropists from around the world. The tales include Canadian novelist Margaret Atwood, Indigenous Ecuadorian leader Nemonte Nenquimo, Swedish climate activist Greta Thunberg, Nigerian activist Esohe Ozigbo, and Thai landscape architect Kotchakorn Voraakhom. These stories remind readers that there are female climate warriors from many different walks of life, helping build confidence in girls that they can make a difference.

A Warmer World: From Polar Bears to Butterflies, How Climate Change Affects Wildlife

By Caroline Arnold, illustrated by Jamie Hogan
Ages: Middle and late elementary school readers

This beautifully illustrated book examines how many species across the globe are both successfully and unsuccessfully adapting to climate change, with a warmer climate, rising sea levels, and melting ice. Although it is written factually, it can help instill a sense of compassion and concern for penguins, foxes, toads, fishes, walruses, krill, and other species as they respond to a changing climate.

What’s the Weather?: Clouds, Climate, and Global Warming

By Fraser Ralston and Judith Ralston
Ages: Elementary school

This informative and entertaining book features bright, eye-catching illustrations and is an excellent resource. Each two-page spread focuses on a different aspect of the weather, introducing intriguing topics like weather-proof animals, city microclimates, weird weather, and volcanic weather. It is both visually appealing and easy to comprehend.

While rising temperatures are having many deleterious effects on global ecosystems, economies and human wellbeing, an interdisciplinary team of researchers at the University of Massachusetts emphasize that temperature alone is not a sufficient basis for climate policy. The team focused on the Antarctic Ice Sheet, which holds the world’s largest store of freshwater — enough to raise the oceans by 58 meters, and which is melting at an accelerating pace. But the physics of the ice sheet itself also contribute to its liquification, which will continue for millennia, even if global carbon emissions are reigned in. And because melting ice can slow rising temperatures in the atmosphere, it is conceivable that the melting ice sheet could help maintain what is commonly considered a “safe” level of warming, 1.5 degrees, say, while actually allowing for devastating sea-level rise. Furthermore, all that Antarctic meltwater won’t cause the same amount of sea-level rise everywhere in the world. Some areas in the Caribbean Sea as well as the Indian and Pacific Oceans will experience a disproportionate share of the sea-level rise from Antarctic ice — up to 33% greater than the global average.

This gap between temperature and sea level has immediate repercussions for many places throughout the world, and especially for the Alliance of Small Island States (AOSIS), an organization of 39 island and coastal nations across the globe. Indeed, the paper’s authors show that, though AOSIS countries have emitted a negligible portion of the planet’s anthropogenic greenhouse gasses, they are bearing the brunt of the world’s rising waters.

“Temperature is not the only way to track global climate change,” says Shaina Sadai, the paper’s lead author, who completed this research as part of her doctoral studies in geosciences at UMass Amherst, “but it became the iconic metric in the Paris Agreement. Knowing that Antarctic melt can delay temperature rise while increasing sea levels, I wondered what it meant for climate justice. But climate science alone can’t answer that question of justice.”

Enter Regine Spector, professor of political science at UMass Amherst and one of the paper’s senior authors. Spector brought expertise in political power dynamics and the history of global inequality to the team’s work to demonstrate how politically powerful countries influence global climate negotiations and continue historic patterns of colonial exploitation experienced by AOSIS nations. “Focusing on temperature misses other real consequences of climate change, such as sea-level rise, that are being felt all over the world today,” says Spector.

The team demonstrates that an interdisciplinary approach to research, which centers the experiences of AOSIS countries, can be used to better understand climate justice impacts of international negotiations and the relationships between science, policy and political power. “We need to listen to the voices of the people facing the vanguard of climate change,” say Sadai and Spector. They hope this research can serve as a model for future studies.

This research was funded by the National Science Foundation and NASA.

Story Source:

Materials provided by University of Massachusetts Amherst. Note: Content may be edited for style and length.

These durable, flexible solar cells, which are much thinner than a human hair, are glued to a strong, lightweight fabric, making them easy to install on a fixed surface. They can provide energy on the go as a wearable power fabric or be transported and rapidly deployed in remote locations for assistance in emergencies. They are one-hundredth the weight of conventional solar panels, generate 18 times more power-per-kilogram, and are made from semiconducting inks using printing processes that can be scaled in the future to large-area manufacturing.

Because they are so thin and lightweight, these solar cells can be laminated onto many different surfaces. For instance, they could be integrated onto the sails of a boat to provide power while at sea, adhered onto tents and tarps that are deployed in disaster recovery operations, or applied onto the wings of drones to extend their flying range. This lightweight solar technology can be easily integrated into built environments with minimal installation needs.

“The metrics used to evaluate a new solar cell technology are typically limited to their power conversion efficiency and their cost in dollars-per-watt. Just as important is integrability — the ease with which the new technology can be adapted. The lightweight solar fabrics enable integrability, providing impetus for the current work. We strive to accelerate solar adoption, given the present urgent need to deploy new carbon-free sources of energy,” says Vladimir Bulović, the Fariborz Maseeh Chair in Emerging Technology, leader of the Organic and Nanostructured Electronics Laboratory (ONE Lab), director of MIT.nano, and senior author of a new paper describing the work.

Joining Bulović on the paper are co-lead authors Mayuran Saravanapavanantham, an electrical engineering and computer science graduate student at MIT; and Jeremiah Mwaura, a research scientist in the MIT Research Laboratory of Electronics. The research is published today in Small Methods.

Slimmed down solar

Traditional silicon solar cells are fragile, so they must be encased in glass and packaged in heavy, thick aluminum framing, which limits where and how they can be deployed.

Six years ago, the ONE Lab team produced solar cells using an emerging class of thin-film materials that were so lightweight they could sit on top of a soap bubble. But these ultrathin solar cells were fabricated using complex, vacuum-based processes, which can be expensive and challenging to scale up.

In this work, they set out to develop thin-film solar cells that are entirely printable, using ink-based materials and scalable fabrication techniques.

To produce the solar cells, they use nanomaterials that are in the form of a printable electronic inks. Working in the MIT.nano clean room, they coat the solar cell structure using a slot-die coater, which deposits layers of the electronic materials onto a prepared, releasable substrate that is only 3 microns thick. Using screen printing (a technique similar to how designs are added to silkscreened T-shirts), an electrode is deposited on the structure to complete the solar module.

The researchers can then peel the printed module, which is about 15 microns in thickness, off the plastic substrate, forming an ultralight solar device.

But such thin, freestanding solar modules are challenging to handle and can easily tear, which would make them difficult to deploy. To solve this challenge, the MIT team searched for a lightweight, flexible, and high-strength substrate they could adhere the solar cells to. They identified fabrics as the optimal solution, as they provide mechanical resilience and flexibility with little added weight.

They found an ideal material — a composite fabric that weighs only 13 grams per square meter, commercially known as Dyneema. This fabric is made of fibers that are so strong they were used as ropes to lift the sunken cruise ship Costa Concordiafrom the bottom of the Mediterranean Sea. By adding a layer of UV-curable glue, which is only a few microns thick, they adhere the solar modules to sheets of this fabric. This forms an ultra-light and mechanically robust solar structure.

“While it might appear simpler to just print the solar cells directly on the fabric, this would limit the selection of possible fabrics or other receiving surfaces to the ones that are chemically and thermally compatible with all the processing steps needed to make the devices. Our approach decouples the solar cell manufacturing from its final integration,” Saravanapavanantham explains.

Outshining conventional solar cells

When they tested the device, the MIT researchers found it could generate 730 watts of power per kilogram when freestanding and about 370 watts-per-kilogram if deployed on the high-strength Dyneema fabric, which is about 18 times more power-per-kilogram than conventional solar cells.

“A typical rooftop solar installation in Massachusetts is about 8,000 watts. To generate that same amount of power, our fabric photovoltaics would only add about 20 kilograms (44 pounds) to the roof of a house,” he says.

They also tested the durability of their devices and found that, even after rolling and unrolling a fabric solar panel more than 500 times, the cells still retained more than 90 percent of their initial power generation capabilities.

While their solar cells are far lighter and much more flexible than traditional cells, they would need to be encased in another material to protect them from the environment. The carbon-based organic material used to make the cells could be modified by interacting with moisture and oxygen in the air, which could deteriorate their performance.

“Encasing these solar cells in heavy glass, as is standard with the traditional silicon solar cells, would minimize the value of the present advancement, so the team is currently developing ultrathin packaging solutions that would only fractionally increase the weight of the present ultralight devices,” says Mwaura.

“We are working to remove as much of the non-solar-active material as possible while still retaining the form factor and performance of these ultralight and flexible solar structures. For example, we know the manufacturing process can be further streamlined by printing the releasable substrates, equivalent to the process we use to fabricate the other layers in our device. This would accelerate the translation of this technology to the market,” he adds.

This research is funded, in part, by the MIT Energy Initiative, the U.S. National Science Foundation, and the Natural Sciences and Engineering Research Council of Canada.

Video: https://youtu.be/TS9ADU0oc50

Assistant Research Professor in UConn’s Institute of the Environment Julissa Rojas-Sandoval explains that invasive plants are non-native species that have been introduced into new areas generally as a result of human activities, and that they are actively spreading, causing harm to the environment, the economy, and human health. Invasive plants may have significant long-term implications for the conservation of native biodiversity, but to combat the problem, we need to know which plants are invasive, where they’re from, and how they got there.

Rojas-Sandoval leads an international collaboration including researchers from all Central American countries, working together to compile the most comprehensive databases of invasive plant species in Central America. The collaboration is called FINCA: Flora Introduced and Naturalized in Central America, and their first paper was published this week in Biological Invasions.

The collaboration arose to meet a need, says Rojas-Sandoval. “While we have a good understanding of the processes and mechanisms of plant invasions in temperate regions, there is a huge gap in our knowledge about biological invasions in the tropics, and this lack of information is limiting our ability to respond to invasive plants.”

Remediation and the impact on the conservation of biodiversity is an important focus, but invasive plants also threaten the social and economic impact aspects of the region. Rojas-Sandoval points out that for places like her native Costa Rica, which relies on eco-tourism and agriculture, the impacts of not dealing with the invasive species could be significant.

It has been suggested that the huge diversity of plants in tropical regions may provide resistance to invasions, meaning that these ecosystems could be less threatened by invasive species because of the competition between so many different plants, but Rojas-Sandoval has studied this topic for the last 15 years and says the problem is greater than is widely understood.

“Across the tropics, the acceleration in the rates of introduction of non-native plants, as well as increments in the rates of habitat loss and forest degradation, are transforming tropical forests and making them more susceptible and less resistant to invasions,” she says.

Rojas-Sandoval explains that, as the juncture between North and South America, Central America is a regional hotspot of biodiversity, home to about 7% of the world’s plant and animal species. The region is also very vulnerable to climate change, she says:

“Climate models predict more extreme events for Central America, more and stronger hurricanes, droughts, and other impacts related to climate change. But we don’t know how climate change is already impacting both native and invasive plant species across this region. That information is necessary to be able to start doing something.”

Rojas-Sandoval and co-author Eduardo Chacón-Madrigal from the University of Costa Rica seized the opportunity and decided to start collecting and compiling any available information to make a comprehensive checklist necessary to address the challenges posed by invasive plants.

They also reached out to other researchers from across Central America to see if they would be interested in collaborating and the timing was fortunate, says Rojas-Sandoval.

“Due to COVID, people were stuck at home and, despite the many difficulties, we all had extra time to collaborate revising lists of species and providing crucial information for the project,” she says.

The team gathered data from herbarium collections in Central America and from collections around the world as well as references from existing botanical surveys, lists of alien species, and other literature.

“We compiled all this information into a list and then sent it to the experts in different countries so they could evaluate it. Then we did a second verification process because we wanted to be completely sure that we were dealing with species that were 100% alien to the region and to validate the occurrence and classification performed by the experts.

“We were able to identify that species from all over the world have been introduced to different countries in Central America, and more than 60% of them have been introduced for ornamental purposes. It is good that we can identify those species, so we know where to focus for later studies.”

The team also determined that invasive plants have made their way into all the major habitats in Central America, and the trend is steadily increasing. This information can now be used to generate specific recommendations for the governments or for the local authorities, to use their resources in the best ways possible to have an impact in controlling the invasive species, says Rojas-Sandoval, adding that the best remedy is prevention — alerting people to the issues before the plants even arrive.

For invasive plants that have already been established, it will take education, persistence, and resources to deal with the problem. However, another important aspect of the problem is that developing countries often don’t have the additional resources needed to fully address the situation.

“The local authorities and people in Central America and other regions in the tropics are already dealing with so many issues, including poverty, climate change, pollution, and over-exploitation of natural resources that it is even more important to optimize the use of any resources available to mitigate the impact of invasive species,” she says. “This is more bad news for many people dealing with so many problems, and it is crucial to increase awareness and support for the issue of biological invasions in the tropics.

“The sooner we start doing something, the better the results will be.”