. Scientific Frontline: Engineering
Showing posts with label Engineering. Show all posts
Showing posts with label Engineering. Show all posts

Thursday, September 28, 2023

Ultrasound may rid groundwater of toxic ‘forever chemicals’

PFAS is notoriously difficult to clean from the environment, but ultrasound may offer a more effective solution compared to past efforts.
Photo Credit: Edward Jenner

New research suggests that ultrasound may have potential in treating a group of harmful chemicals known as PFAS to eliminate them from contaminated groundwater.

Invented nearly a century ago, per- and poly-fluoroalkyl substances, also known as “forever chemicals,” were once widely used to create products such as cookware, waterproof clothing and personal care items. Today, scientists understand that exposure to PFAS can cause a number of human health issues such as birth defects and cancer. But because the bonds inside these chemicals don’t break down easily, they’re notoriously difficult to remove from the environment.

Such difficulties have led researchers at The Ohio State University to study how ultrasonic degradation, a process that uses sound to degrade substances by cleaving apart the molecules that make them up, might work against different types and concentrations of these chemicals.

By conducting experiments on lab-made mixtures containing three differently sized compounds of fluorotelomer sulfonates – PFAS compounds typically found in firefighting foams – their results showed that over a period of three hours, the smaller compounds degraded much faster than the larger ones. This is in contrast to many other PFAS treatment methods in which smaller PFAS are actually more challenging to treat.

Purdue researchers develop a new type of intelligent architected materials for industry applications

Products made with intelligent architected materials developed at Purdue University have the ability to change from one stable configuration to another stable configuration and back again. The technology is being tested in new aircraft runway mats, nonpneumatic tires and other applications.
Image Credit: Provided by the researchers. Courtesy of Purdue University

Purdue University civil engineering researchers have developed patent-pending intelligent architected materials that can dissipate energy caused by bending, compression, torque and tensile stresses, avoiding permanent plastic deformation or damage, and may also exhibit shape memory properties that allow them to have actuation capacity.

Avoiding damage makes the material reusable and improves human safety and structure durability in products across several industrial sectors.

Pablo Zavattieri, the Jerry M. and Lynda T. Engelhardt Professor in Civil Engineering, leads the research team that has developed this new class of intelligent architected materials.

“These materials are designed for fully recoverable, energy-dissipating structures, akin to what is referred to as architected shape memory materials, or phase transforming cellular materials, known as PXCM,” Zavattieri said. “They can also exhibit intelligent responses to external forces, changes in temperature and other external stimuli.”

Intelligent architected materials such as these have a wide range of potential applications due to their unique properties.

Listening to atoms moving at the nanoscale

Professor Jan Seidel and his research lab have been using specialised techniques to listen to atoms moving.
Photo Credit: UNSW FLEET Centre.

Understanding how the phenomenon of ‘crackling noise’ occurs at the microscopic scale could have implications for new research in materials science and medicine.

Scientists from UNSW Sydney and the University of Cambridge have used novel methods to listen to the sounds of atoms moving under pressure – a phenomenon known as ‘crackling noise’.

These atomic movements occur in avalanches – they are similar to snow avalanches, but made of atoms – and follow very well-defined statistical rules.

Crackling noise can be observed every day, from crumpling paper and candy wrapping, to the crackling of your cereal, as well as in natural occurrences, such as earthquakes.

In a study recently published in Nature Communications, Professor Jan Seidel and his lab, from the School of Material Science and Engineering, were able to record the crackling noise of just a few hundred atoms, in experiments that lasted over eight hours.

Wednesday, September 27, 2023

Noninvasive, ultrasound-based brain biopsy is feasible

Graduate student Lu Xu wears a device designed by engineers, at Washington University in St. Louis, that targets ultrasound waves to precise spots in the brain. Such targeting is the first step in a sonobiopsy, a noninvasive technique invented by Washington University researchers that uses ultrasound and microbubbles to release biomolecules from brain tumors. The biomolecules then can be collected via a blood draw, analyzed and used to inform treatment decisions. Xu is part of a research team that demonstrated that sonobiopsy is safe and feasible for use in people.
Photo Credit: Courtesy of Hong Chen

The blood-brain barrier, the body’s way of shielding sensitive brain tissue from viruses, toxins and other harmful substances in the blood, can pose a problem for physicians caring for patients with suspected brain diseases such as cancer. Molecular and genetic information would be invaluable for confirming a diagnosis and guiding treatment decisions, but such molecules are normally confined to the brain by the barrier. Neurosurgeons routinely perform surgical brain biopsies to obtain this data on brain tumors, but such procedures carry risks and are not feasible for all tumors or for many other kinds of brain diseases.

Researchers at Washington University in St. Louis have developed an anatomically precise technique called sonobiopsy that uses ultrasound and microbubbles to disrupt the barrier temporarily and allow RNA, DNA and proteins from the brain to spill out into the blood, where they can be detected and analyzed. The researchers developed and previously tested the technique in animals. In a new study, available online in the journal NPJ Precision Oncology, they showed that the technique is feasible and safe for use in people, and could open the door to noninvasive biopsies for suspected brain tumors and other brain diseases.

Understanding bacterial motors may lead to more efficient nanomachine motors

The FliG protein in the "bacterial motor"
Illustration Credit: Atsushi Hijikata, Yohei Miyanoiri, Osaka University

A research group led by Professor Emeritus Michio Homma (he, him) and Professor Seiji Kojima (he, him) of the Graduate School of Science at Nagoya University, in collaboration with Osaka University and Nagahama Institute of Bio-Science and Technology, have made new insights into how locomotion occurs in bacteria. The group identified the FliG molecule in the flagellar layer, the ‘motor’ of bacteria, and revealed its role in the organism. These findings suggest ways in which future engineers could build nanomachines with full control over their movements. They published the study in iScience

As nanomachines become smaller, researchers are taking inspiration from microscopic organisms for ways to make them move and operate. In particular, the flagellar motor can rotate clockwise and counterclockwise at a speed of 20,000 rpm. If scaled up, it would be comparable to a Formula One engine with an energy conversion efficiency of almost 100% and the capacity to change its rotation direction instantly at high speeds. Should engineers be able to develop a device like a flagellar motor, it would radically increase the maneuverability and efficiency of nanomachines. 

Monday, September 25, 2023

Copper-based catalysts efficiently turn carbon dioxide into methane

Soumyabrata Roy is a Rice University postdoctoral research associate in materials science and nanoengineering and the study’s lead author.
Photo Credit: Gustavo Raskosky/Rice University
Technologies for removing carbon from the atmosphere keep improving, but solutions for what to do with the carbon once it’s captured are harder to come by.

The lab of Rice University materials scientist Pulickel Ajayan and collaborators developed a way to wrest the carbon from carbon dioxide and affix it to hydrogen atoms, forming methane ⎯ a valuable fuel and industrial feedstock. According to the study published in Advanced Materials, the method relies on electrolysis and catalysts developed by grafting isolated copper atoms on two-dimensional polymer templates.

“Electricity-driven carbon dioxide conversion can produce a large array of industrial fuels and feedstocks via different pathways,” said Soumyabrata Roy, a research scientist in the Ajayan lab and the study’s lead author. “However, carbon dioxide-to-methane conversion involves an eight-step pathway that raises significant challenges for selective and energy-efficient methane production.

“Overcoming such issues can help close the artificial carbon cycle at meaningful scales, and the development of efficient and affordable catalysts is a key step toward achieving this goal.”

Thursday, June 15, 2023

This salty gel could harvest water from desert air

MIT engineers have synthesized a superabsorbent material that can soak up a record amount of moisture from the air, even in desert-like conditions. Pictured are the hydrogel discs swollen in water.
 Photo Credit: Gustav Graeber and Carlos D. Díaz-Marín

MIT engineers have synthesized a superabsorbent material that can soak up a record amount of moisture from the air, even in desert-like conditions.

As the material absorbs water vapor, it can swell to make room for more moisture. Even in very dry conditions, with 30 percent relative humidity, the material can pull vapor from the air and hold in the moisture without leaking. The water could then be heated and condensed, then collected as ultrapure water.

The transparent, rubbery material is made from hydrogel, a naturally absorbent material that is also used in disposable diapers. The team enhanced the hydrogel’s absorbency by infusing it with lithium chloride — a type of salt that is known to be a powerful dessicant.

The researchers found they could infuse the hydrogel with more salt than was possible in previous studies. As a result, they observed that the salt-loaded gel absorbed and retained an unprecedented amount of moisture, across a range of humidity levels, including very dry conditions that have limited other material designs.

Wednesday, June 14, 2023

UC Irvine scientists create long-lasting, cobalt-free, lithium-ion batteries

“We are basically the first group that started thinking about the supply chain, or the pain point, that nickel will bring to the EV industry in a matter of, I would say, three to five years,” says Huolin Xin, UCI professor of physics & astronomy, lead author of a paper in Nature Energy on a new way to use nickel in lithium-ion batteries.
Photo Credit: Steve Zylius / UCI

In a discovery that could reduce or even eliminate the use of cobalt – which is often mined using child labor – in the batteries that power electric cars and other products, scientists at the University of California, Irvine have developed a long-lasting alternative made with nickel.

“Nickel doesn’t have child labor issues,” said Huolin Xin, the UCI professor of physics & astronomy whose team devised the method, which could usher in a new, less controversial generation of lithium-ion batteries. Until now, nickel wasn’t a practical substitute because large amounts of it were required to create lithium batteries, he said. And the metal’s cost keeps climbing.

To become an economically viable alternative to cobalt, nickel-based batteries needed to use as little nickel as possible.

“We’re the first group to start going in a low-nickel direction,” said Xin, whose team published its findings in the journal Nature Energy. “In a previous study by my group, we came up with a novel solution to fully eliminate cobalt. But that formulation still relied on a lot of nickel.”

A New Magnetizable Shape Memory Alloy with Low Energy Loss, Even at Low Temperatures

Image Credit: Scientific Frontline

Shape memory alloys (SMA) remember their original shape and return to it after being heated. Similar to how a liquid transforms into a gas when boiled, SMAs undergo a phase transformation when heated or cooled. The phase transformation occurs with the movement of atoms, which is invisible to the naked eye.

SMAs are utilized in a diverse array of applications, including as actuators and sensors. However, the need to cool or heat SMAs means there is a delay in their phase transformation.

As a recently invented type of SMA, metamagnetic shape memory alloys (MMSMA) negate this limited response rate thanks to their ability to undergo phase transformation when exposed to an external magnetic field. Yet to date, MMSMAs have failed to solve another common problem with most SMAs: the fact that they lose a large amount of energy when phase transforming - something that worsens substantially in low temperatures.

Tuesday, June 13, 2023

AI helps show how the brain’s fluids flow

A video shows a perivascular space (area within white lines) into which the researchers injected tiny particles. The particles (shown as moving dots) are trailed by lines which indicate their direction. Having measured the position and velocity of the particles over time, the team then integrated this 2D video with physics-informed neural networks to create an unprecedented high-resolution, 3D look at the brain’s fluid flow system.
Video Credit: Douglas Kelley

New research targets diseases including Alzheimer’s.

A new artificial intelligence-based technique for measuring fluid flow around the brain’s blood vessels could have big implications for developing treatments for diseases such as Alzheimer’s.

The perivascular spaces that surround cerebral blood vessels transport water-like fluids around the brain and help sweep away waste. Alterations in the fluid flow are linked to neurological conditions, including Alzheimer’s, small vessel disease, strokes, and traumatic brain injuries but are difficult to measure in vivo.

A multidisciplinary team of mechanical engineers, neuroscientists, and computer scientists led by University of Rochester Associate Professor Douglas Kelley developed novel AI velocimetry measurements to accurately calculate brain fluid flow. The results are outlined in a study published by Proceedings of the National Academy of Sciences.

Wednesday, June 7, 2023

New research could improve performance of artificial intelligence and quantum computers

A University of Minnesota Twin Cities-led team has developed a more energy-efficient, tunable superconducting diode — a promising component for future electronic devices — that could help scale up quantum computers for industry and improve artificial intelligence systems.
Photo Credit: Olivia Hultgren.

A University of Minnesota Twin Cities-led team has developed a new superconducting diode, a key component in electronic devices, that could help scale up quantum computers for industry use and improve the performance of artificial intelligence systems. 

The paper is published in Nature Communications, a peer-reviewed scientific journal that covers the natural sciences and engineering. 

A diode allows current to flow one way but not the other in an electrical circuit. It essentially serves as half of a transistor — which is the main element in computer chips. Diodes are typically made with semiconductors, substances with electrical properties that form the base for most electronics and computers, but researchers are interested in making them with superconductors, which additionally have the ability to transfer energy without losing any power along the way.

Compared to other superconducting diodes, the researchers’ device is more energy efficient, can process multiple electrical signals at a time, and contains a series of gates to control the flow of energy, a feature that has never before been integrated into a superconducting diode.

Tuesday, June 6, 2023

A lung injury therapy derived from adult skin cells

Natalia Higuita-Castro, seated, with the core team that worked in the lab on this study during the COVID-19 lockdown (L-R): Maria Angelica Rincon-Benavides, a PhD student in the Biophysics Graduate Program, and biomedical engineering postdoctoral fellows Ana Salazar-Puerta and Tatiana Cuellar-Gaviria.
Photo Credit: Matt Schutte

Therapeutic nanocarriers engineered from adult skin cells can curb inflammation and tissue injury in damaged mouse lungs, new research shows, hinting at the promise of a treatment for lungs severely injured by infection or trauma.

Researchers conducted experiments in cell cultures and mice to demonstrate the therapeutic potential of these nanoparticles, which are extracellular vesicles similar to the ones circulating in humans’ bloodstream and biological fluids that carry messages between cells. 

The hope is that a drop of solution containing these nanocarriers, delivered to the lungs via the nose, could treat acute respiratory distress syndrome (ARDS), one of the most frequent causes of respiratory failure that leads to putting patients on a ventilator. In ARDS, inflammation spiraling out of control in the lungs so seriously burdens the immune system that immune cells are unable to tend to the initial cause of the damage. 

Tuesday, May 16, 2023

Insight into brain’s waste clearing system may shed light on brain diseases

The image shows a microscopic image revealing the enhanced glymphatic transport of an intranasally delivered tracer (red), achieved using ultrasound combined with microbubbles.
Image Credit: Chen lab

Like the lymphatic system in the body, the glymphatic system in the brain clears metabolic waste and distributes nutrients and other important compounds. Impairments in this system may contribute to brain diseases, such as neurodegenerative diseases and stroke.

A team of researchers in the McKelvey School of Engineering at Washington University in St. Louis has found a noninvasive and nonpharmaceutical method to influence glymphatic transport using focused ultrasound, opening the opportunity to use the method to further study brain diseases and brain function. Results of the work are published in Proceedings of the National Academy of Sciences May 15, 2023.

Hong Chen, associate professor of biomedical engineering in McKelvey Engineering and of neurological surgery in the School of Medicine, and her team, including Dezhuang (Summer) Ye, a postdoctoral research associate, and Si (Stacie) Chen, a former postdoctoral research associate, found the first direct evidence that focused ultrasound, combined with circulating microbubbles — a technique they call FUSMB — could mechanically enhance glymphatic transport in the mouse brain. 

Focused ultrasound can penetrate the scalp and skull to reach the brain and precisely target a defined region within the brain. In previous work, Chen’s team found that microbubbles injected into the bloodstream amplify the effects of the ultrasound waves on the blood vessels and generate a pumping effect, which helps with the accumulation of intranasally-delivered agents in the brain, such as drugs or gene therapy treatments.

Monday, May 15, 2023

New priming method improves battery life, efficiency

Quan Nguyen (left), Sibani Lisa Biswal and collaborators developed a prelithiation technique that helps improve the performance of lithium-ion batteries with silicon anodes.
Photo Credit: Jeff Fitlow/Rice University

Silicon anode batteries have the potential to revolutionize energy storage capabilities, which is key to meeting climate goals and unlocking the full potential of electric vehicles.

However, the irreversible depletion of lithium ions in silicon anodes puts a major constraint on the development of next-generation lithium-ion batteries.

Scientists at Rice University’s George R. Brown School of Engineering have developed a readily scalable method to optimize prelithiation, a process that helps mitigate lithium loss and improves battery life cycles by coating silicon anodes with stabilized lithium metal particles (SLMPs).

The Rice lab of chemical and biomolecular engineer Sibani Lisa Biswal found that spray-coating the anodes with a mixture of the particles and a surfactant improves battery life by 22% to 44%. Battery cells with a greater amount of the coating initially achieved a higher stability and cycle life. However, there was a drawback: When cycled at full capacity, a larger amount of the particle coating led to more lithium trapping, causing the battery to fade more rapidly in subsequent cycles.

Friday, May 12, 2023

Study reveals new ways for exotic quasiparticles to “relax”

By sandwiching bits of perovskite between two mirrors and stimulating them with laser beams, researchers were able to directly control the spin state of quasiparticles known as exciton-polariton pairs, which are hybrids of light and matter.
Illustration Credit: Courtesy of the researchers
(CC BY-NC-ND 3.0)

New findings from a team of researchers at MIT and elsewhere could help pave the way for new kinds of devices that efficiently bridge the gap between matter and light. These might include computer chips that eliminate inefficiencies inherent in today’s versions, and qubits, the basic building blocks for quantum computers, that could operate at room temperature instead of the ultracold conditions needed by most such devices.

The new work, based on sandwiching tiny flakes of a material called perovskite in between two precisely spaced reflective surfaces, is detailed in the journal Nature Communications, in a paper by MIT recent graduate Madeleine Laitz PhD ’22, postdoc Dane deQuilettes, MIT professors Vladimir Bulovic, Moungi Bawendi and Keith Nelson, and seven others.

By creating these perovskite sandwiches and stimulating them with laser beams, the researchers were able to directly control the momentum of certain “quasiparticles” within the system. Known as exciton-polariton pairs, these quasiparticles are hybrids of light and matter. Being able to control this property could ultimately make it possible to read and write data to devices based on this phenomenon.

Thursday, May 11, 2023

NUS scientists develop a novel light-field sensor for 3D scene construction with unprecedented angular resolution

Prof Liu Xiaogang (right) and Dr Yi Luying from the NUS Department of Chemistry capturing a 3D image of a model using the light-field sensor.
Photo Credit: Courtesy of National University of Singapore

Color-encoding technique for light-field imaging has potential applications in fields such as autonomous driving, virtual reality and biological imaging

A research team from the National University of Singapore (NUS) Faculty of Science, led by Professor Liu Xiaogang from the Department of Chemistry, has developed a 3D imaging sensor that has an extremely high angular resolution, which is the capacity of an optical instrument to distinguish points of an object separated by a small angular distance, of 0.0018o. This innovative sensor operates on a unique angle-to-color conversion principle, allowing it to detect 3D light fields across the X-ray to visible light spectrum.  

A light field encompasses the combined intensity and direction of light rays, which the human eyes can process to precisely detect the spatial relationship between objects. Traditional light sensing technologies, however, are less effective. Most cameras, for instance, can only produce two-dimensional images, which is adequate for regular photography but insufficient for more advanced applications, including virtual reality, self-driving cars, and biological imaging. These applications require precise 3D scene construction of a particular space.

Wednesday, May 10, 2023

Jellybeans – a sweet solution for overcrowded circuitry in quantum computer chips

Engineers show that a jellybean-shaped quantum dot creates more breathing space in a microchip packed with qubits.

The silicon microchips of future quantum computers will be packed with millions, if not billions of qubits – the basic units of quantum information – to solve the greatest problems facing humanity. And with millions of qubits needing millions of wires in the microchip circuitry, it was always going to get cramped in there.

But now engineers at UNSW Sydney have made an important step towards solving a long-standing problem about giving their qubits more breathing space -- and it all revolves around jellybeans.

Not the kind we rely on for a sugar hit to get us past the 3pm slump. But jellybean quantum dots –elongated areas between qubit pairs that create more space for wiring without interrupting the way the paired qubits interact with each other.

As lead author Associate Professor Arne Laucht explains, the jellybean quantum dot is not a new concept in quantum computing, and has been discussed as a solution to some of the many pathways towards building the world’s first working quantum computer.

Monday, May 8, 2023

An unprecedented view of gene regulation

Caption:“Using this method, we generate the highest-resolution maps of the 3D genome that have ever been generated, and what we see are a lot of interactions between enhancers and promoters that haven't been seen previously,” says Anders Sejr Hansen, the Underwood-Prescott Career Development Assistant Professor of Biological Engineering at MIT. 
Video Credit: Melanie Gonick/MIT

Much of the human genome is made of regulatory regions that control which genes are expressed at a given time within a cell. Those regulatory elements can be located near a target gene or up to 2 million base pairs away from the target.

To enable those interactions, the genome loops itself in a 3D structure that brings distant regions close together. Using a new technique, MIT researchers have shown that they can map these interactions with 100 times higher resolution than has previously been possible.

“Using this method, we generate the highest-resolution maps of the 3D genome that have ever been generated, and what we see are a lot of interactions between enhancers and promoters that haven't been seen previously,” says Anders Sejr Hansen, the Underwood-Prescott Career Development Assistant Professor of Biological Engineering at MIT and the senior author of the study. “We are excited to be able to reveal a new layer of 3D structure with our high resolution.”

The researchers’ findings suggest that many genes interact with dozens of different regulatory elements, although further study is needed to determine which of those interactions are the most important to the regulation of a given gene.

Monday, May 1, 2023

The Trumpet biocomputing platform heralds a new path for medicine

A biocomputing chip made of bacteria.
Image Credit: College of Biological Sciences / University of Minnesota

From early detection and internal treatment of diseases to futuristic applications like augmenting human memory, biological computing, or biocomputing, it has the potential to revolutionize medicine and computers. Traditional computer hardware is limited in its ability to interface with living organs, which has constrained the development of medical devices. Computerized implants require a constant supply of electricity, they can cause scarring in soft tissue that makes them unusable and they cannot heal themselves the way organisms can. Through the use of biological molecules such as DNA or proteins, biocomputing has the potential to overcome these limitations.

Biocomputing is typically done either with live cells or with non-living, enzyme-free molecules. Live cells can feed themselves and can heal, but it can be difficult to redirect cells from their ordinary functions towards computation. Non-living molecules solve some of the problems of live cells, but have weak output signals and are difficult to fine-tune and regulate. 

Sunday, April 30, 2023

Study unlocks potential breakthrough in Type 1 diabetes treatment

Omid Veiseh and Boram Kim. Kim is holding a medical-grade catheter similar to ones used in the study experiments.
Photo Credit: Gustavo Raskosky/Rice University

For the over 8 million people around the globe living with Type 1 diabetes, getting a host immune system to tolerate the presence of implanted insulin-secreting cells could be life-changing.

Rice University bioengineer Omid Veiseh and collaborators identified new biomaterial formulations that could help turn the page on Type 1 diabetes treatment, opening the door to a more sustainable, long-term, self-regulating way to handle the disease.

To do so, they developed a new screening technique that involves tagging each biomaterial formulation in a library of hundreds with a unique “barcode” before implanting them in live subjects.

According to the study in Nature Biomedical Engineering, using one of the alginate formulations to encapsulate human insulin-secreting islet cells provided long-term blood sugar level control in diabetic mice. Catheters coated with two other high-performing materials did not clog up.

“This work was motivated by a major unmet need,” said Veiseh, a Rice assistant professor of bioengineering and Cancer Prevention and Research Institute of Texas scholar. “In Type 1 diabetes patients, the body’s immune system attacks the insulin-producing cells of the pancreas. As those cells are killed off, the patient loses the ability to regulate their blood glucose.”

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