Research yields eco-friendly way to separate, recycle refrigerants tied to climate crisis

Lead author Abby Harders, who earned her doctorate in chemical and petroleum engineering at the University of Kansas, now serves as head of research and development at Icorium Engineering, situated in KU’s Innovation Park.
Photo Credit: Max Jiang

A scholarly report in the journal Science Advances from researchers at the University of Kansas shows a new eco-friendly method for separating the chemicals found in common refrigerants for easier recycling at industrial scale.

“The motivation of this work is to enable separation of highly complex gaseous refrigerant mixtures,” said lead author Abby Harders, who performed the research as a KU doctoral student in the research group of co-author Mark Shiflett, Foundation Distinguished Professor of Chemical and Petroleum Engineering. “This effort has been driven by climate legislation phasing out certain hydrofluorocarbon (HFC) refrigerants.”

The paper's key innovation uses membranes — amorphous fluorinated polymers, to be specific — that efficiently isolate complex refrigerant mixtures. Other separation methods, like distillation, are less effective because of the complex composition of the mixtures. Harders said the membranes are fabricated to allow some gases to pass through while restricting others — resulting in effective purification.

To demonstrate the technology could scale to industrial viability, the team — including many associated with KU’s Wonderful Institute for Sustainable Engineering — developed a custom-coating process to create submicron coatings on the membrane’s porous supports, creating composite hollow fibers. The results show a functional prototype, proving the technology’s usefulness to firms engaged in refrigerant recovery and reuse. 

Collection of tiny antennas can amplify and control light polarized in any direction

New polarization-independent, highly resonant metasurfaces can precisely amplify and control light without requiring incoming light (top left) to be oriented and traveling in a certain direction.
Image Credit: Bo Zhao

Antennas receive and transmit electromagnetic waves, delivering information to our radios, televisions, cell phones and more. Researchers in the McKelvey School of Engineering at Washington University in St. Louis imagines a future where antennas reshape even more applications.

Their new metasurfaces, ultra-thin materials made of tiny nanoantennas that can both amplify and control light in very precise ways, could replace conventional refractive surfaces from eyeglasses to smartphone lenses and improve dynamic applications such as augmented reality/virtual reality and LiDAR.

While metasurfaces can manipulate light very precisely and efficiently, enabling powerful optical devices, they often suffer from a major limitation: Metasurfaces are highly sensitive to the polarization of light, meaning they can only interact with light that is oriented and traveling in a certain direction. While this is useful in polarized sunglasses that block glare and in other communications and imaging technologies, requiring a specific polarization dramatically reduces the flexibility and applicability of metasurfaces.

Engineers Design New Autonomous System to Monitor Arctic Ice Melt

Photo Credit: Bernd Hildebrandt

The rapid melting and thinning of the Arctic ice have sparked serious concerns in the scientific community. In addition, sea ice thickness also has decreased, which makes ice cover more vulnerable to warming air and ocean temperature.

Understanding the ecological role of sea ice in the Arctic is crucial, particularly because the extent of sea ice in the region has been decreasing at an unprecedented rate. What would happen to the Arctic marine ecosystem if the sea ice melted even faster? To answer these questions, a long-term monitoring and data collection system is necessary in the harsh Arctic environment.

However, direct observation is challenging as satellite sensors have a coarse spatial resolution and cannot detect the fine fractal structure of the ice. Deploying human-crewed ships to the area is also difficult due to extreme weather conditions and obstacles posed by floating broken ice. Moreover, traditional ocean observation methods offer limited temporal and spatial coverage, while drones and autonomous underwater vehicles (AUVs) are hindered by energy constraints that restrict their research potential.

To overcome these challenges, researchers from the College of Engineering and Computer Science at Florida Atlantic University have proposed a design of an alternative, autonomous observational method, which holds promise for improving the autonomy of marine vehicles, aiding in maritime missions, and gaining a deeper understanding of how melting Arctic sea ice affects marine ecosystems.

FAU Engineering Develops New Weapon against Harmful Algal Blooms

Photo Credit: Tom Fisk

As harmful algal blooms (HABs) continue to spread across the globe, urgent research is needed to address this growing threat. Studies in Italy, China, and the Atlantic basin have shown that many water bodies have high nitrogen-to-phosphorus ratios, making phosphorus a key factor that drives these blooms. This highlights the critical need for more effective phosphorus management strategies to curb the rise of HABs and protect our ecosystems.

Recently, there’s been a growing interest in finding useful ways to repurpose troublesome algal biomass, which could be turned into valuable products like bioplastics, biofertilizers, and biofuels. Researchers have already explored using algal biomass to create materials that can help clean up things such as heavy metals, rare earth metals, dyes, and even capture CO2 and harmful volatile organic compounds from the air.

However, few studies have looked into how algal biomass, especially cyanobacteria, also known as blue-green algae, can be used to create materials that remove phosphate from water.

Now, researchers from the College of Engineering and Computer Science at Florida Atlantic University, have filled that gap by transforming cyanobacterial biomass, which is typically a hazardous waste, into custom-made adsorbent materials that can pull harmful phosphorus out of water. A d sorbent materials are substances that can attract and hold molecules or particles such as gases, liquids, or dissolved solids on their surface. Unlike a b sorbent materials that soak up substances into their structure, a d sorbents capture molecules on the outside surface, forming a thin layer.

One Step Coating Could Save Lives and Property

Image Credit: Rachel Barton/Texas A&M Engineering Communications

Although extremely flammable, cotton is one of the most commonly used textiles due to its comfort and breathable nature. However, in a single step, researchers from Texas A&M University can reduce the flammability of cotton using a polyelectrolyte complex coating. The coating can be tailored for various textiles, such as clothing or upholstery, and scaled using the common pad-dry coating process, which is suitable for industrial applications. This technology can help to save property and lives on a large scale. 

“Many of the materials in our day-to-day lives are flammable, and offering a solution to protect from fire benignly is difficult,” said Maya D. Montemayor, a graduate student in the Department of Chemistry at Texas A&M and the publication’s lead author. “This technology can be optimized to quickly, easily and safely flame retard many flammable materials, offering vast protection in everyday life, saving money and lives of the general population.” 

Current studies developing flame retardant coatings deposited via polyelectrolyte complexation require two or more steps, increasing the time and cost to coat a material effectively. 

Researchers find dialysis ‘astonishingly effective’ for treating wastewater

Menachem Elimelech and Yuanmiaoliang “Selina” Chen.
Photo Credit: Gustavo Raskosky/Rice University

Researchers at Rice University, in collaboration with Guangdong University of Technology, have uncovered an innovative approach to treating high-salinity organic wastewaters — streams containing both elevated salt and organic concentrations — by employing dialysis, a technology borrowed from the medical field.

For patients with kidney failure, dialysis uses a machine called a dialyzer to filter waste and excess fluid from the blood; blood is drawn from the body, cleansed in the dialyzer then returned through a separate needle or tube.

In a new study published in Nature Water, the team found that mimicking this same method can separate salts from organic substances with minimal dilution of the wastewater, simultaneously addressing key limitations of conventional methods. This novel pathway has the potential to reduce environmental impacts, lower costs and enable the recovery of valuable resources across a range of industrial sectors.

MIT engineers design flexible “skeletons” for soft, muscle-powered robots

MIT engineers have developed a new spring (shown in Petri dish) that maximizes the work of natural muscles. When living muscle tissue is attached to posts at the corners of the device, the muscle’s contractions pull on the spring, forming an effective, natural actuator. The spring can serve as a “skeleton” for future muscle-powered robots.
Photo Credit: Felice Frankel
(CC BY-NC-ND 4.0 DEED)

Our muscles are nature’s perfect actuators — devices that turn energy into motion. For their size, muscle fibers are more powerful and precise than most synthetic actuators. They can even heal from damage and grow stronger with exercise.

For these reasons, engineers are exploring ways to power robots with natural muscles. They’ve demonstrated a handful of “biohybrid” robots that use muscle-based actuators to power artificial skeletons that walk, swim, pump, and grip. But for every bot, there’s a very different build, and no general blueprint for how to get the most out of muscles for any given robot design.

Now, MIT engineers have developed a spring-like device that could be used as a basic skeleton-like module for almost any muscle-bound bot. The new spring, or “flexure,” is designed to get the most work out of any attached muscle tissues. Like a leg press that’s fit with just the right amount of weight, the device maximizes the amount of movement that a muscle can naturally produce.

The researchers found that when they fit a ring of muscle tissue onto the device, much like a rubber band stretched around two posts, the muscle pulled on the spring, reliably and repeatedly, and stretched it five times more, compared with other previous device designs.

The team sees the flexure design as a new building block that can be combined with other flexures to build any configuration of artificial skeletons. Engineers can then fit the skeletons with muscle tissues to power their movements.

This 3D printer can figure out how to print with an unknown material

Researchers developed a 3D printer that can automatically identify the parameters of an unknown material on its own.
Photo Credit: Courtesy of the researchers
(CC BY-NC-ND 4.0 DEED)

While 3D printing has exploded in popularity, many of the plastic materials these printers use to create objects cannot be easily recycled. While new sustainable materials are emerging for use in 3D printing, they remain difficult to adopt because 3D printer settings need to be adjusted for each material, a process generally done by hand.

To print a new material from scratch, one must typically set up to 100 parameters in software that controls how the printer will extrude the material as it fabricates an object. Commonly used materials, like mass-manufactured polymers, have established sets of parameters that were perfected through tedious, trial-and-error processes.

But the properties of renewable and recyclable materials can fluctuate widely based on their composition, so fixed parameter sets are nearly impossible to create. In this case, users must come up with all these parameters by hand.

Researchers tackled this problem by developing a 3D printer that can automatically identify the parameters of an unknown material on its own.

New machine to enhance understanding of nuclear weapons’ behavior

Bob Webster, deputy Laboratory director for Weapons (far right); Mike Furlanetto, Scorpius Advanced Sources and Detection project director (center); and Geoffrey Zehnder, project engineer (far left); discuss the prototype module Lab employees constructed for Scorpius' first accelerator cells and modules.
Photo Credit: Courtesy of Los Alamos National Laboratory

On March 7, assembly began at Los Alamos National Laboratory on a groundbreaking machine that will allow scientists to use real plutonium in experiments while studying the conditions immediately before the nuclear phase of a weapon's functioning. The machine will prove instrumental in the Laboratory's stockpile stewardship mission, which ensures the safety, security and reliability of the nation's nuclear weapons through computational tools and engineering test facilities, rather than underground testing.

Although the plutonium used will never reach criticality — the condition that forms a self-sustaining nuclear reaction — the tests performed as part of the Scorpius Advanced Sources and Detection (ASD) project will provide essential knowledge about how the key element in nuclear weapons behaves.

The components being built will be the first two accelerator cell modules for Scorpius.

"This means we have officially started building, and I am so looking forward to seeing this experiment in my lifetime," said Bob Webster, deputy Laboratory director for Weapons.

Electrochemistry helps clean up electronic waste recycling, precious metal mining

A new study from the University of Illinois Urbana-Champaign shows how electrochemistry can be used to extract precious metals from discarded electronics in an efficient and environmentally friendly manner. 
Photo Credit: Fred Zwicky

A new method safely extracts valuable metals locked up in discarded electronics and low-grade ore using dramatically less energy and fewer chemical materials than current methods, report University of Illinois Urbana-Champaign researchers in the journal Nature Chemical Engineering. 

Gold and platinum group metals such as palladium, platinum and iridium are in high demand for use in electronics. However, sourcing these metals from mining and current electronics recycling techniques is not sustainable and comes with a high carbon footprint. Gold used in electronics accounts for 8% of the metal’s overall demand, and 90% of the gold used in electronics ends up in U.S. landfills yearly, the study reports. 

The study, led by chemical and biomolecular engineering professor Xiao Su, describes the first precious metal extraction and separation process fully powered by the inherent energy of electrochemical liquid-liquid extraction, or e-LLE. The method uses a reduction-oxidation reaction to selectively extract gold and platinum group metal ions from a liquid containing dissolved electronic waste. 

Novel electrochemical sensor detects dangerous bacteria

By using a customized surface to bait the targeted pathogens, they separate by themselves from a mixture of many different bacteria. This makes it easy to detect them electrochemically.
Illustration Credit: Sebastian Balser, Andreas Terfort Research Group, Goethe University Frankfurt

Researchers at Goethe University Frankfurt and Kiel University have developed a novel sensor for the detection of bacteria. It is based on a chip with an innovative surface coating. This ensures that only very specific microorganisms adhere to the sensor – such as certain pathogens. The larger the number of organisms, the stronger the electric signal generated by the chip. In this way, the sensor is able not only to detect dangerous bacteria with a high level of sensitivity but also to determine their concentration. 

Each year, bacterial infections claim several million lives worldwide. That is why detecting harmful microorganisms is crucial – not only in the diagnosis of diseases but also, for example, in food production. However, the methods available so far are often time-consuming, require expensive equipment or can only be used by specialists. Moreover, they are often unable to distinguish between active bacteria and their decay products. 

By contrast, the newly developed method detects only intact bacteria. It makes use of the fact that microorganisms only ever attack certain body cells, which they recognize from the latter's specific sugar molecule structure. This matrix, known as the glycocalyx, differs depending on the type of cell. It serves, so to speak, as an identifier for the body cells. This means that to capture a specific bacterium, we need only to know the recognizable structure in the glycocalyx of its preferred host cell and then use this as “bait".

New All-Liquid Iron Flow Battery for Grid Energy Storage

Lead author and battery researcher Gabriel Nambafu assembles a test flow battery apparatus.
Photo Credit:  Andrea Starr | Pacific Northwest National Laboratory

A commonplace chemical used in water treatment facilities has been repurposed for large-scale energy storage in a new battery design by researchers at the Department of Energy’s Pacific Northwest National Laboratory. The design provides a pathway to a safe, economical, water-based, flow battery made with Earth-abundant materials. It provides another pathway in the quest to incorporate intermittent energy sources such as wind and solar energy into the nation’s electric grid.

The researchers report in Nature Communications that their lab-scale, iron-based battery exhibited remarkable cycling stability over one thousand consecutive charging cycles, while maintaining 98.7 percent of its maximum capacity. For comparison, previous studies of similar iron-based batteries reported degradation of the charge capacity two orders of magnitude higher, over fewer charging cycles.

Iron-based flow batteries designed for large-scale energy storage have been around since the 1980s, and some are now commercially available. What makes this battery different is that it stores energy in a unique liquid chemical formula that combines charged iron with a neutral-pH phosphate-based liquid electrolyte, or energy carrier. Crucially, the chemical, called nitrogenous triphosphonate, nitrilotri-methylphosphonic acid or NTMPA, is commercially available in industrial quantities because it is typically used to inhibit corrosion in water treatment plants.

New reactor could save millions when making ingredients for plastics and rubber from natural gas

Illustration Credit: Courtesy of University of Michigan / Department of Chemical Engineering

A new way to make an important ingredient for plastics, adhesives, carpet fibers, household cleaners and more from natural gas could reduce manufacturing costs in a post-petroleum economy by millions of dollars, thanks to a new chemical reactor designed by University of Michigan engineers.

The reactor creates propylene, a workhorse chemical that is also used to make a long list of industrial chemicals, including ingredients for nitrile rubber found in automotive hoses and seals as well as blue protective gloves. Most propylene used today comes from oil refineries, which collect it as a byproduct of refining crude oil into gasoline.

As oil and gasoline fall out of vogue in favor of natural gas, solar, and wind energy, production of propylene and other oil-derived products could fall below the current demand without new ways to make them.

Natural gas extracted from shale holds one potential alternative to propylene sourced from crude oil. It’s rich in propane, which resembles propylene closely enough to be a promising precursor material, but current methods to make propylene from natural gas are still too inefficient to bridge the gap in supply and demand.

“It’s very hard to economically convert propane into propylene,” said Suljo Linic, the Martin Lewis Perl Collegiate Professor of Chemical Engineering and the corresponding author of the study published in Science.

Bridge in a box: Unlocking origami’s power to produce load-bearing structures

From left, Yi Zhu, a Research Fellow in Mechanical Engineering, and Evgueni Filipov, an associate professor in both Civil and Environmental Engineering and Mechanical Engineering, working in his lab in the George G. Brown Laboratories Building.
Image Credit: Brenda Ahearn/University of Michigan, College of Engineering, Communications and Marketing

For the first time, load-bearing structures like bridges and shelters can be made with origami modules—versatile components that can fold compactly and adapt into different shapes—University of Michigan engineers have demonstrated.

It’s an advance that could enable communities to quickly rebuild facilities and systems damaged or destroyed during natural disasters, or allow for construction in places that were previously considered impractical, including outer space. The technology could also be used for structures that need to be built and then disassembled quickly, such as concert venues and event stages.

“With both the adaptability and load-carrying capability, our system can build structures that can be used in modern construction,” said Evgueni Filipov, an associate professor of civil and environmental engineering and of mechanical engineering, and a corresponding author of the study in Nature Communications.

Principles of the origami art form allow for larger materials to be folded and collapsed into small spaces. And with modular building systems gaining wider acceptance, the applications for components that can be stored and transported with ease have grown.

Rice research could advance soft robotics manufacturing, design

Te Faye Yap (left) and Daniel Preston
Photo Credit: Jeff Fitlow/Rice University

Soft robots use pliant materials such as elastomers to interact safely with the human body and other challenging, delicate objects and environments. A team of Rice University researchers has developed an analytical model that can predict the curing time of platinum-catalyzed silicone elastomers as a function of temperature. The model could help reduce energy waste and improve throughput for elastomer-based components manufacturing.

“In our study, we looked at elastomers as a class of materials that enables soft robotics, a field that has seen a huge surge in growth over the past decade,” said Daniel Preston, a Rice assistant professor of mechanical engineering and corresponding author on a study published in Cell Reports Physical Science. “While there is some related research on materials like epoxies and even on several specific silicone elastomers, until now there was no detailed quantitative account of the curing reaction for many of the commercially available silicone elastomers that people are actually using to make soft robots. Our work fills that gap.”

The platinum-catalyzed silicone elastomers that Preston and his team studied typically start out as two viscoelastic liquids that, when mixed together, transform over time into a rubbery solid. As a liquid mixture, they can be poured into intricate molds and thus used for casting complex components. The curing process can occur at room temperature, but it can also be sped up using heat.

Manufacturing processes involving elastomers have typically relied on empirical estimates for temperature and duration to control the curing process. However, this ballpark approach makes it difficult to predict how elastomers will behave under varying curing conditions. Having a quantitative framework to determine exactly how temperature impacts curing speed will enable manufacturers to maximize efficiency and reduce waste.

Sandia collaboration produces improved microneedle technology

Adam Bolotsky demonstrates how Sandia National Laboratories, in collaboration with SRI, has enhanced the extraction of interstitial fluid. The improved extraction method gets more fluid in less time.
Photo Credit: Craig Fritz

Microneedles measure only two to three times the diameter of human hair and are about a millimeter long. But their impact is significant, from helping U.S. service members in the field diagnose infections earlier, to helping individuals monitor their own health.

Sandia National Laboratories is at the forefront of microneedle research and is partnering with others to expand the technology.

A microneedle is a minimally invasive way to sample interstitial fluid from under the skin. Interstitial fluid shares many similarities with blood, but there is still much to learn about it.

“When we started work in this field in 2011, our goal was to develop microneedles as a wearable sensor, as an alternate to blood samples,” said Ronen Polsky, who has led Sandia’s work in microneedles. Microneedles can access interstitial fluid for real-time and continuous measurements of circulating biomarkers.

“People wear continuous glucose monitors for blood sugar measurements,” Polsky said. “We want to expand this to a whole range of other conditions to take advantage of this minimally invasive sampling using microneedles.”

SwRI develops off-road autonomous driving tools focused on camera vision

SwRI is exploring using stereo cameras, or stereovision, as an alternative to lidar sensors in automated vehicles. SwRI's stereovision algorithms create disparity maps that estimate the depth of roadway features and obstacles. The left image shows how a conventional camera sees an off-road trail. The middle image shows a lidar image of the same trail. The right image shows a stereovision disparity map based on SwRI's algorithms, where colors indicate the distance of detected objects (yellow is near and blue is far). The gray/white in the lidar image suggests the outline of trees and a vehicle hood, but it does not indicate depth or distance.
Image Credit: Courtesy of Southwest Research Institute

Southwest Research Institute has developed off-road autonomous driving tools with a focus on stealth for the military and agility for space and agriculture clients. The vision-based system pairs stereo cameras with novel algorithms, eliminating the need for lidar and active sensors.

“We reflected on the toughest machine vision challenges and then focused on achieving dense, robust modeling for off-road navigation,” said Abe Garza, a research engineer in SwRI’s Intelligent Systems Division.

Through internal research, SwRI engineers developed a suite of tools known as the Vision for Off-Road Autonomy (VORA). The passive system can perceive objects, model environments and simultaneously localize and map while navigating off-road environments.

The VORA team envisioned a camera system as a passive sensing alternative to lidar, a light detection and ranging sensor, that emits active lasers to probe objects and calculate depth and distance. Though highly reliable, lidar sensors produce light that can be detected by hostile forces. Radar, which emits radio waves, is also detectable. GPS navigation can be jammed, and its signals are often blocked in canyons and mountains, which can limit agricultural automation.

Nanosurgical tool could be key to cancer breakthrough

Electron microscopy image of the nanopipette.
Photo Credit: Dr Alexander Kulak

A nanosurgical tool - about 500 times thinner than a human hair - could give insights into cancer treatment resistance that no other technology has been able to do, according to a new study.

The high-tech double-barrel nanopipette, developed by University of Leeds scientists, and applied to the global medical challenge of cancer, has - for the first time - enabled researchers to see how individual living cancer cells react to treatment and change over time – providing vital understanding that could help doctors develop more effective cancer medication.  

The tool has two nanoscopic needles, meaning it can simultaneously inject and extract a sample from the same cell, expanding its potential uses. And the platform’s high level of semi-automation has sped up the process dramatically, enabling scientists to extract data from many more individual cells, with far greater accuracy and efficiency than previously possible, the study shows. 

Currently, techniques for studying single cells usually destroy them, meaning a cell can be studied either before treatment, or after.  

This device can take a “biopsy” of a living cell repeatedly during exposure to cancer treatment, sampling tiny extracts of its contents without killing it, enabling scientists to observe its reaction over time. 

During the study, the multi-disciplinary team, featuring biologists and engineers, tested cancer cells’ resistance to chemotherapy and radiotherapy using glioblastoma (GBM) - the deadliest form of brain tumor - as a test case, because of its ability to adapt to treatment and survive. 

Completely recycled viscose for the first time

Edvin Bågenholm-Ruuth
Photo Credit: Courtesy of Lund University

At present, viscose textiles are made of biomass from the forest, and there is no such thing as fully recycled viscose. Researchers at Lund University in Sweden have now succeeded in making new viscose – from worn-out cotton sheets.

Old textiles around the world end up at the rubbish tip and are often burned. In Sweden, they are generally burned to produce district heating. Extensive development work is being conducted to give old clothes and textiles a worthier ending. 

The planet really needs recycled textiles, as it takes a lot of energy, water and land to cultivate cotton and other plant sources for textiles. 

However, there are many challenges.

“Cellulose chains, the main component in plant fibers, are complex and long. Cotton textiles are also intensively treated with dyes, protective agents and other chemicals. And then there is all the ingrained grime in the form of skin flakes and fats,” says Edvin Bågenholm-Ruuth, doctoral student in chemical engineering at Lund University. 

Possible ‘Trojan Horse’ found for treating stubborn bacterial infections

Transmission electron microscope (TEM) image of the bacterial cell with an extracellular vesicle attached.
Image Credit: Courtesy of Washington State University

Bacteria can be tricked into sending death signals to stop the growth of their slimy, protective homes that lead to deadly infections, a new study demonstrates.

The discovery by Washington State University researchers could someday be harnessed as an alternative to antibiotics for treating difficult infections. Reporting in the journal Biofilm, the researchers used the messengers, which they named death extracellular vesicles (D-EVs), to reduce growth of the bacterial communities by up to 99.99% in laboratory experiments.

“Adding the death extracellular vesicles to the bacterial environment, we are kind of cheating the bacteria cells,” said Mawra Gamal Saad, first author on the paper and a graduate student in WSU’s Gene and Linda Voiland School of Chemical Engineering and Bioengineering. “The cells don’t know which type of EVs they are, but they take them up because they are used to taking them from their environment, and with that, the physiological signals inside the cells change from growth to death.”