Producing extreme ultraviolet laser pulses efficiently through wakesurfing behind electron beams

A 3D simulation of the wake behind the electron beam (purple) and how a light pulse (blue and red stripe) might surf behind it. The plasma wake is shown in alternating yellow for the absence of electrons and green for peaks in the electron density. When a light pulse sits on that boundary, it can continuously gain energy—the trick is keeping it there.
Image Credit: Ryan Sandberg, High Field Science Group

Simulations suggest this mechanism could provide a tenfold increase in frequency—likely hitting a peak power of 100 trillion watts in XUV

A laser pulse surfing in the wake of an electron beam pulse could get upshifted from visible to extreme ultraviolet light, simulations done at the University of Michigan have shown.

The approach could enable more efficient generation of high-energy laser light, perhaps even to X-rays. The 3D simulation showed up to a tenfold increase in the frequency of the light, while the 1D simulation went up to a 50-fold increase. In principle, the researchers say it is possible to continue amping up the energy of the laser pulse by extending the period of time that it can ride in the wake of the electron beam.

“Future lasers, potentially including those used to pattern semiconductor chips for computers, could take advantage of this effect to produce higher energy pulses more efficiently,” said Alec Thomas, U-M professor of nuclear engineering and radiological sciences and corresponding author of the study in Physical Review Letters.

Custom, 3D-printed heart replicas look and pump just like the real thing

No two hearts beat alike. The size and shape of the heart can vary from one person to the next. These differences can be particularly pronounced for people living with heart disease, as their hearts and major vessels work harder to overcome any compromised function.

MIT engineers are hoping to help doctors tailor treatments to patients’ specific heart form and function, with a custom robotic heart. The team has developed a procedure to 3D print a soft and flexible replica of a patient’s heart. They can then control the replica’s action to mimic that patient’s blood-pumping ability.

The procedure involves first converting medical images of a patient’s heart into a three-dimensional computer model, which the researchers can then 3D print using a polymer-based ink. The result is a soft, flexible shell in the exact shape of the patient’s own heart. The team can also use this approach to print a patient’s aorta — the major artery that carries blood out of the heart to the rest of the body.

To mimic the heart’s pumping action, the team has fabricated sleeves similar to blood pressure cuffs that wrap around a printed heart and aorta. The underside of each sleeve resembles precisely patterned bubble wrap. When the sleeve is connected to a pneumatic system, researchers can tune the outflowing air to rhythmically inflate the sleeve’s bubbles and contract the heart, mimicking its pumping action. 

New Hope for People Living with Paralysis after Stroke

Video Credit: Carnegie Mellon University

Globally, every fourth adult over the age of 25 will suffer a stroke in their lifetime, and 75% of those people will have lasting deficits in fine motor control. Until now, treating paralysis in the so-called chronic stage, which begins six months after the stroke, has remained ineffective.

Technology developed by Douglas Weber, the Akhtar and Bhutta Professor of Mechanical Engineering and the Neuroscience Institute at Carnegie Mellon University in collaboration with the University of Pittsburgh is offering new hope for people living with impairments that would otherwise be considered permanent. The team discovered that muscles respond directly to electrical stimulation of specific spinal cord regions enabling patients to regain mobility of their arm and hand.  

Spinal cord stimulation technology uses a set of electrodes placed on the surface of the spinal cord to deliver pulses of electricity that activate the nerve cells inside. Research groups around the world have shown that this stimulation can be used to restore movement to the legs, but the complexity of the neural signals controlling the unique dexterity of the human hand and arm adds a significantly higher set of challenges.

Engineers discover a new way to control atomic nuclei as “qubits”

Diagram illustrates the way two laser beams of slightly different wavelengths can affect the electric fields surrounding an atomic nucleus, pushing against this field in a way that nudges the spin of the nucleus in a particular direction, as indicated by the arrow.
Illustration Credit: Courtesy of the researchers | MIT
Creative Commons

In principle, quantum-based devices such as computers and sensors could vastly outperform conventional digital technologies for carrying out many complex tasks. But developing such devices in practice has been a challenging problem despite great investments by tech companies as well as academic and government labs.

Today’s biggest quantum computers still only have a few hundred “qubits,” the quantum equivalents of digital bits.

Now, researchers at MIT have proposed a new approach to making qubits and controlling them to read and write data. The method, which is theoretical at this stage, is based on measuring and controlling the spins of atomic nuclei, using beams of light from two lasers of slightly different colors. The findings are described in a paper published Tuesday in the journal Physical Review X, written by MIT doctoral student Haowei Xu, professors Ju Li and Paola Cappellaro, and four others.

Nuclear spins have long been recognized as potential building blocks for quantum-based information processing and communications systems, and so have photons, the elementary particles that are discreet packets, or “quanta,” of electromagnetic radiation. But coaxing these two quantum objects to work together was difficult because atomic nuclei and photons barely interact, and their natural frequencies differ by six to nine orders of magnitude.

Two-dimensional oxides open door for high-speed electronics

Furkan Turker, graduate student in the Department of Materials Sciences, works on a silicon carbide chip in the laboratory 
Photo Credit: Pennsylvania State University
 Creative Commons

Advances in computing power over the decades have come thanks in part to our ability to make smaller and smaller transistors, a building block of electronic devices, but we are nearing the limit of the silicon materials typically used. A new technique for creating 2D oxide materials may pave the way for future high-speed electronics, according to an international team of scientists.

“One way we can make our transistors, our electronic devices, work faster is to shrink the distance electrons have to travel between point A and B,” said Joshua Robinson, professor of materials science and engineering at Penn State. “You can only go so far with 3D materials like silicon — once you shrink it down to a nanometer, its properties change. So, there’s been a massive push looking at new materials, one of which are 2D materials.”

The team, led by Furkan Turker, graduate student in the Department of Materials Sciences, used a technique called confinement hetroepitaxy, or CHet, to create 2D oxides, materials with special properties that can serve as an atomically thin insulating layer between layers of electrically conducting materials.

“Now we can create essentially the world’s thinnest oxides — just a few atoms thick,” Turker said. “That allows you to bring conducting layers closer together than ever without letting them touch. This enables the formation of an ultrathin barrier between conducting layers, which is essential for the fabrication of next-generation electronic devices, such as diodes or transistors.”

Engineering skin grafts for complex body parts

A bioengineered glove of human skin created for grafting.
Photo Credit: Alberto Pappalardo and Hasan Erbil Abaci / Columbia University Vagelos College of Physicians and Surgeons

Skin grafts are a vital treatment for burns and other extensive skin injuries. Since the 1980s, advances in bioengineering have allowed researchers to grow new patches of skin in the lab. Such engineered grafts are less traumatic for patients than transplanting skin from elsewhere on the body.

To date, available techniques have only allowed such skin patches to be produced in shapes similar to bandages, such as flat rectangles or circles. These shapes work well to cover wounds on flat surfaces like the back. But using them on complex structures like the hands or face requires extensive cutting and suturing, which can cause damage and scarring.

A research team led by Dr. Hasan Erbil Abaci of Columbia University has been working on methods to make 3D engineered skin in the shape of complex body parts. Such custom grafts could then be transplanted intact, with minimal suturing required. In a new study, the team tested their skin-culture system using models of human hands and the hindlimbs of mice. Results were published on January 27, 2023, in Science Advances.

Kangaroo fecal microbes could reduce methane from cows

Photo Credit: sandid

Baby kangaroo feces might help provide an unlikely solution to the environmental problem of cow-produced methane. A microbial culture developed from the kangaroo feces inhibited methane production in a cow stomach simulator in a Washington State University study.

After researchers added the baby kangaroo culture and a known methane inhibitor to the simulated stomach, it produced acetic acid instead of methane. Unlike methane, which cattle discard as flatulence, acetic acid has benefits for cows as it aids muscle growth. The researchers published their work in the journal Biocatalysis and Agricultural Biotechnology.

“Methane emissions from cows are a major contributor to greenhouse gases, and at the same time, people like to eat red meat,” said Birgitte Ahring, corresponding author on the paper and a professor in with the Bioproducts, Sciences and Engineering Laboratory at the WSU Tri-Cities campus. “We have to find a way to mitigate this problem.”

Reducing the burps and farts of methane emissions from cattle is no laughing matter. Methane is the second largest greenhouse gas contributor and is about 30 times more potent at heating up the atmosphere than carbon dioxide. More than half of the methane released to the atmosphere is thought to come from the agricultural sector, and ruminant animals, such as cattle and goats, are the most significant contributors. Furthermore, the process of producing methane requires as much as 10% of the animal’s energy.

‘Magic’ solvent creates stronger thin films

This micrograph image shows an initiated chemical vapor deposition coating made by doctoral student Pengyu Chen in the lab of Rong Yang, assistant professor in the Smith School of Chemical and Biomolecular Engineering in Cornell Engineering.
Image Credit: Courtesy of the researchers 

A new all-dry polymerization technique uses reactive vapors to create thin films with enhanced properties, such as mechanical strength, kinetics and morphology. The synthesis process is gentler on the environment than traditional high-temperature or solution-based manufacturing and could lead to improved polymer coatings for microelectronics, advanced batteries and therapeutics.

“This scalable technique of initiated chemical vapor deposition polymerization allows us to make new materials, without redesigning or revamping the whole chemistry. We just simply add an ‘active’ solvent,” said Rong Yang, assistant professor in the Smith School of Chemical and Biomolecular Engineering in Cornell Engineering. “It’s a little bit like a Lego. You team up with a new connecting piece. There’s a ton you can build now that you couldn’t do before.”

Yang collaborated on the project with Jingjie Yeo, assistant professor in the Sibley School of Mechanical and Aerospace Engineering, and Shefford Baker, associate professor of materials science and engineering.

Ingestible sensor could help doctors pinpoint GI difficulties

MIT engineers have shown that they can use magnetic fields to track the location of this ingestible sensor within the GI tract.
Photo Credit: Courtesy of the researchers / Massachusetts Institute of Technology

Engineers at MIT and Caltech have demonstrated an ingestible sensor whose location can be monitored as it moves through the digestive tract, an advance that could help doctors more easily diagnose gastrointestinal motility disorders such as constipation, gastroesophageal reflux disease, and gastroparesis.

The tiny sensor works by detecting a magnetic field produced by an electromagnetic coil located outside the body. The strength of the field varies with distance from the coil, so the sensor’s position can be calculated based on its measurement of the magnetic field.

In the new study, the researchers showed that they could use this technology to track the sensor as it moved through the digestive tract of large animals. Such a device could offer an alternative to more invasive procedures, such as endoscopy, that are currently used to diagnose motility disorders.

“Many people around the world suffer from GI dysmotility or poor motility, and having the ability to monitor GI motility without having to go into a hospital is important to really understand what is happening to a patient,” says Giovanni Traverso, an associate professor of mechanical engineering at MIT and a gastroenterologist at Brigham and Women’s Hospital.

Creating 3D objects with sound

The use of sound waves to create a pressure field to print particles. 
Image Credit: © MPI for Medical Research, Heidelberg University/ Kai Melde

Creating 3D objects with sound

Scientists from the Max Planck Institute for Medical Research and the Heidelberg University have created a new technology to assemble matter in 3D. Their concept uses multiple acoustic holograms to generate pressure fields with which solid particles, gel beads and even biological cells can be printed. These results pave the way for novel 3D cell culture techniques with applications in biomedical engineering.

Additive manufacturing or 3D printing enables the fabrication of complex parts from functional or biological materials. Conventional 3D printing can be a slow process, where objects are constructed one line or one layer at a time. Researchers in Heidelberg and Tübingen now demonstrate how to form a 3D object from smaller building blocks in just a single step. “We were able to assemble microparticles into a three-dimensional object within a single shot using shaped ultrasound”, says Kai Melde, postdoc in the group and first author of the study. “This can be very useful for bioprinting. The cells used there are particularly sensitive to the environment during the process”, adds Peer Fischer, Professor at Heidelberg University.

Inhalable ‘SHIELD’ Protects Lungs Against COVID-19, Flu Viruses

Photo Credit: Robina Weermeijer

Researchers have developed an inhalable powder that could protect lungs and airways from viral invasion by reinforcing the body’s own mucosal layer. The powder, called Spherical Hydrogel Inhalation for Enhanced Lung Defense, or SHIELD, reduced infection in both mouse and non-human primate models over a 24-hour period, and can be taken repeatedly without affecting normal lung function.

“The idea behind this work is simple – viruses have to penetrate the mucus in order to reach and infect the cells, so we’ve created an inhalable bioadhesive that combines with your own mucus to prevent viruses from getting to your lung cells,” says Ke Cheng, corresponding author of the paper describing the work. “Mucus is the body’s natural hydrogel barrier; we are just enhancing that barrier.”

Cheng is the Randall B. Terry, Jr. Distinguished Professor in Regenerative Medicine at North Carolina State University’s College of Veterinary Medicine and a professor in the NC State/UNC-Chapel Hill Joint Department of Biomedical Engineering.

The inhalable powder microparticles are composed of gelatin and poly(acrylic acid) grafted with a non-toxic ester. When introduced to a moist environment – such as the respiratory tract and lungs – the microparticles swell and adhere to the mucosal layer, increasing the “stickiness” of the mucus.

Researchers develop elastic material that is impervious to gases and liquids

This image shows a container made of the new material that is elastic, flexible, and impervious to both gases and liquids. The material can be used to make ‘soft’ batteries for use with wearable electronics and other devices.
Photo Credit: Michael Dickey.

An international team of researchers has developed a technique that uses liquid metal to create an elastic material that is impervious to both gases and liquids. Applications for the material include use as packaging for high-value technologies that require protection from gases, such as flexible batteries.

“This is an important step because there has long been a trade-off between elasticity and being impervious to gases,” says Michael Dickey, co-corresponding author of a paper on the work and the Camille & Henry Dreyfus Professor of Chemical and Biomolecular Engineering at North Carolina State University.

“Basically, things that were good at keeping gases out tended to be hard and stiff. And things that offered elasticity allowed gases to seep through. We’ve come up with something that offers the desired elasticity while keeping gases out.”

Researchers Develop New Method to Improve Burn Assessment

The handheld THz Scanner is shown in operation.
Photo Credit: Terahertz Biophotonics Laboratory, Stony Brook University

Stony Brook Engineers Employ New Device and Neural Networks with Terahertz Spectroscopy

An important component to a more successful treatment course for burns is correctly assessing them, and current methods are not accurate enough. A team of Stony Brook University researchers believe they created a new method to significantly improve burn assessment. They are employing a physics-based neural network model that uses terahertz time-domain spectroscopy (THz-TDS) data for non-invasive burn assessment. The team combines the approach with a handheld imaging device that they developed specifically for fast THz-TDS imaging of burn injuries. Details of their method are published in a paper in Biomedical Optics Express.

Studies have shown that the accuracy of burn diagnosis is only about 60 to 75 percent when trying to decide which one of the burns needs surgical intervention (skin grafting) or which burns can heal spontaneously. The Stony Brook team has found with their method using THz-TDS — broadly defined as detecting and measuring properties of matter with picosecond short pulses of electromagnetic fields — that THz spectroscopic imaging can increase the accuracy rate of burn diagnosis and classification to approximately 93 percent.

Smart Contact Lens that Diagnoses and Treats Glaucoma

Schematic illustration of a theranostic smart contact lens for glaucoma treatment.
Illustration Credit: Pohang University of Science and Technology

POSTECH research team led by Professor Sei Kwang Hahn proposes a new paradigm for monitoring and control of intraocular pressure in glaucoma patients.

Glaucoma is a common ocular disease in which the optic nerve malfunctions due to the increased intraocular pressure (IOP) caused by drainage canal blocking in the eye. This condition narrows the peripheral vision and can lead to vision loss in severe cases. Glaucoma patients have to manage IOP levels for their lifetime. Automatic monitoring and control of the IOP in these patients would significantly improve their quality of life.

Recently, a research team at POSTECH has developed a smart contact lens by combining an IOP sensor and a flexible drug delivery system to manage IOP measurement and medication administration.

The moon is too hot and too cold; now it could be just right for humans, thanks to newly available science

Issam Mudawar’s research on heat transfer could enable space habitats to be built in extreme environments like the moon.
Photo Credit: Purdue University / John Underwood

With temperatures on the moon ranging from minus 410 to a scorching 250 degrees Fahrenheit, it’s an understatement to say that humans will need habitats with heat and air conditioning to survive there long term.

But heating and cooling systems won’t be effective enough to support habitats for lunar exploration or even longer trips to Mars without an understanding of what reduced gravity does to boiling and condensation. Engineers haven’t been able to crack this science – until now.

“Every refrigerator, every air conditioning system we have on Earth involves boiling and condensation. Those same mechanisms are also prevalent in numerous other applications, including steam power plants, nuclear reactors and both chemical and pharmaceutical industries,” said Issam Mudawar, Purdue University’s Betty Ruth and Milton B. Hollander Family Professor of Mechanical Engineering. “We have developed over a hundred years’ worth of understanding of how these systems work in Earth’s gravity, but we haven’t known how they work in weightlessness.”

A team of engineers at Purdue led by Mudawar, who is collaborating with NASA’s Glenn Research Center in Cleveland, has spent 11 years developing a facility to investigate these phenomena.

A quasiparticle that can transfer heat under electrical control

Because thermal conductivity in this class of materials can be changed with application of an external electric field at room temperature, they hold promise for use in heat switches for everyday applications, like collection of solar power.
Photo Credit: American Public Power Association

Scientists have found the secret behind a property of solid materials known as ferroelectrics, showing that quasiparticles moving in wave-like patterns among vibrating atoms carry enough heat to turn the material into a thermal switch when an electrical field is applied externally.

A key finding of the study is that this control of thermal conductivity is attributable to the structure of the material rather than any random collisions among atoms. Specifically, the researchers describe quasiparticles called ferrons whose polarization changes as they “wiggle” in between vibrating atoms – and it’s that ordered wiggling and polarization, receptive to the externally applied electrical field, that dictates the material’s ability to transfer the heat at a different rate.

“We figured out that this change in position of these atoms, and the change of the nature of the vibrations, must carry heat, and therefore the external field which changes this vibration must affect the thermal conductivity,” said senior author Joseph Heremans, professor of mechanical and aerospace engineering, materials science and engineering, and physics at The Ohio State University. 

How sound waves trigger immune responses to cancer in mice

The 700kHz, 260-element histotripsy ultrasound array transducer used in Prof. Xu’s lab.
Photo Credit: Marcin Szczepanski/Lead Multimedia Storyteller, Michigan Engineering

Technique pioneered at the University of Michigan could improve outcomes for cancer and neurological conditions

When noninvasive sound waves break apart tumors, they trigger an immune response in mice. By breaking down the cell wall “cloak,” the treatment exposes cancer cell markers that had previously been hidden from the body’s defenses, researchers at the University of Michigan have shown.

The technique developed at Michigan, known as histotripsy, offers a two-prong approach to attacking cancers: the physical destruction of tumors via sound waves and the kickstarting of the body’s immune response. It could potentially offer medical professionals a treatment option for patients without the harmful side effects of radiation and chemotherapy.

Until now, researchers didn’t understand how histotripsy was activating the immune system. A study from last spring showed that histotripsy breaks down liver tumors in rats, leading to the complete disappearance of the tumor even when sound waves are applied to only 50% to 75% of the mass. The immune response also prevented further spread, with no evidence of recurrence or metastases in more than 80% of the animals.

How to make hydrogels more injectable

MIT and Harvard researchers have developed computational models that can predict the properties of materials made from squishy hydrogel blocks.
Image Credit: Courtesy of the researchers

Gel-like materials that can be injected into the body hold great potential to heal injured tissues or manufacture entirely new tissues. Many researchers are working to develop these hydrogels for biomedical uses, but so far very few have made it into the clinic.

To help guide in the development of such materials, which are made from microscale building blocks akin to squishy LEGOs, MIT and Harvard University researchers have created a set of computational models to predict the material’s structure, mechanical properties, and functional performance outcomes. The researchers hope that their new framework could make it easier to design materials that can be injected for different types of applications, which until now has been mainly a trial-and-error process.

“It’s really exciting from a material standpoint and from a clinical application standpoint,” says Ellen Roche, an associate professor of mechanical engineering and a member of the Institute for Medical Engineering and Science at MIT. “More broadly, it’s a nice example of taking lab-based data and synthesizing it into something usable that can give you predictive guidelines that could be applied to things beyond these hydrogels.”

Groundbreaking Biomaterial Heals Tissues From the Inside Out

The biomaterial is based on a hydrogel that Christman's lab developed.
Photo Credit: University of California, San Diego

A new biomaterial that can be injected intravenously, reduces inflammation in tissue and promotes cell and tissue repair. The biomaterial was tested and proven effective in treating tissue damage caused by heart attacks in both rodent and large animal models. Researchers also provided proof of concept in a rodent model that the biomaterial could be beneficial to patients with traumatic brain injury and pulmonary arterial hypertension.

“This biomaterial allows for treating damaged tissue from the inside out,” said Karen Christman, a professor of bioengineering at the University of California San Diego, and the lead researcher on the team that developed the material. “It’s a new approach to regenerative engineering.”

A study on the safety and efficacy of the biomaterial in human subjects could start within one to two years, Christman added. The team, which brings together bioengineers and physicians, presented their findings in Nature Biomedical Engineering.

Lockheed Martin’s First LM 400 Multi-Mission Spacecraft Completed, Ready For Final Testing

Lockheed Martin’s first LM 400 mid-sized, multi-mission spacecraft will launch in 2023 as a technology demonstrator.
Resized Image using AI by SFLORG
Photo Credit: Lockheed Martin Corporation

The first Lockheed Martin LM 400, a flexible, mid-sized satellite customizable for military, civil or commercial users, rolled off the company’s digital factory production line and is advancing toward its planned 2023 launch.

The agile LM 400 spacecraft bus design enables one platform to support multiple missions, including remote sensing, communications, imaging, radar and persistent surveillance. Lockheed Martin invested in common satellite designs to support demand for more proliferated systems, high-rate production and affordable solutions. The LM 400 is scalable and versatile starting at the size of the average home refrigerator, with capability to grow for higher power and larger payloads and packaged to enable multiple satellites per launch.

The LM 400 bus can operate in low, medium or geosynchronous earth orbits, providing greater flexibility than other buses in this class. The LM 400 space vehicle is compatible with a wide range of launch vehicles in a single, ride-share or multi-launch configuration.