Shock-Absorbing, Reusable Body Armor

Mechanical engineers from Johns Hopkins University in Baltimore have found a new way to build body armor with a lightweight elastomer material that relies on a complex liquid crystal structure. The resulting armor is “lighter, stronger, and reusable,” according to the university’s press release. That could be a game-changer in the highly deformable world of body armor.

Sung Hoon Kang—senior author of the new paper, published in February in the journal Advanced Materials—is part of the tantalizingly named Hopkins Extreme Materials Institute (HEMI), established in 2012 to study “science associated with materials and structures under extreme conditions and demonstrating extreme performance.” Its projects are funded by organizations like the U.S. Department of Energy and the National Science Foundation, with areas of study including things like how materials behave in Earth’s mantle.

It’s easy to see how Earth’s mantle is extreme, with some of the highest temperatures and pressures on the planet. Body armor is a different application, but something that is still very extreme: absorbing gunshots, for example, and spreading that energy out in a way that does not harm the wearer is no small feat.

We are excited about our findings on the extreme energy absorption capability of the new material,” Kang says in the statement.

The idea of a material that can outperform today’s helmets and car bumpers piqued Kang’s curiosity. One of the major areas for improvement is deformation, which is the way the force of an impact presses material way out of shape. Think of a car’scrumple zone,” which is literally designed to collapse to absorb impact; you’re not exactly “reusing” that portion of the car afterward, especially in higher-speed crashes.

Many helmet and impact-absorbing materials dissipate energy through inelastic mechanisms, such as plastic deformation and fracture and fragmentation. However, these materials can become permanently damaged after one-time usage and are not suitable for repeated use,” the researchers write.

So if the non-reusable mechanisms are inelastic—which makes sense, the opposite of elastic and therefore unable to “bounce back”—how do we do things differently? This is where the idea of metamaterials comes into play. A metamaterial is something carefully engineered on the micro-scale to have properties that a simple layer of plywood or metal would not have. The goal is to build better functionality starting at the atomic level.

Source: https://hub.jhu.edu/
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https://www.popularmechanics.com/

Robot Performs much Better than Humans at Surgery

For years, the world of medicine has been steadily advancing the art of robot-assisted procedures, enabling doctors to enhance their technique inside the operating theatre. Now US researchers say a robot has successfully performed keyhole surgery on pigs all on its own without the guiding hand of a human. Furthermore, they add, the robot surgeon produced “significantly better” results than humans.

Smart Tissue Autonomous Robot (Star) carried out laparoscopic surgery to connect two ends of an intestine in four pigs. The robot excelled at the procedure, which requires a high level of precision and repetitive movements

Axel Krieger, of Johns Hopkins University, said it marked the first time a robot had performed laparoscopic surgery without human help. “Our findings show that we can automate one of the most intricate and delicate tasks in surgery: the reconnection of two ends of an intestine,” he said. “The Star performed the procedure in four animals and it produced significantly better results than humans performing the same procedure.”

Connecting two ends of an intestine is a challenging procedure in gastrointestinal surgery, requiring a surgeon to apply stitches – or sutures – with high accuracy and consistency. Even a slight hand tremor or misplaced stitch can result in a leak that could result in a patient suffering fatal complications. Krieger, an assistant professor of mechanical engineering at Johns Hopkins, helped create the robot, a vision-guided system designed specifically to suture soft tissue. It improves a 2016 model that repaired a pig’s intestines, but required a large incision to access the intestine and more guidance from humans.
Experts say new features allow for improved surgical precision, including specialised suturing tools and imaging systems that provide more accurate visualisations of the surgical field.
Source: https://www.theguardian.com/

Two New Trials of Coronavirus Treatment

Drugs used for treating arthritis are being tested as treatments for COVID-19, the disease caused by a new coronavirus, as researchers rush to find ways of helping patients and slowing the number of infectionsSanofi and Regeneron Pharmaceuticals said on Monday they began a clinical trial of their rheumatoid arthritis drug Kevzara as a coronavirus treatment, while in Spain a separate trial is studying if a combination of two drugs can slow down the spread of coronavirus among people. Enrolments for the mid-to-late stage trial of Kevzara, an immune-system modifying drug known as a monoclonal antibody, will begin immediately and test up to 400 patients, Sanofi and Regeneron said in a joint statement. Regeneron in February announced a partnership with the U.S. Department of Health and Human Services to develop a treatment for the new coronavirus, called SARS-CoV2, and said it would focus on monoclonal antibodies.

The virus that emerged in central China in December has now infected more than 179,000 people worldwide, according to the Johns Hopkins University, which is tracking these figures. Doctors have seen that many of those who become critically ill from SARS-CoV2 are experiencing a so-called cytokine storm, which happens when the immune system overreacts and attacks the body’s organs. Some researchers think drugs that can suppress the immune system, including monoclonal antibodies, might be useful for limiting this autoimmune response.

Meanwhile, Barcelona-based researchers said on Monday they would administer a drug used to treat HIV – containing darunavir and cobicistat – to a coronavirusinfected person. The patient’s close contacts would be administered hydroxychloroquine, a drug for malaria and rheumatoid conditions because laboratory experiments suggest it prevents this strain of coronavirus from reproducing. “The goal of our study is to separate the transmission chains,” Oriol Mitja, researcher at Germans Trias i Pujol Research Institute, told a news briefing. Patients with coronavirus can infect between 5% and 15% of the people they come into contact with during the 14 days after starting to show symptoms, he said. The trial’s goal is to reduce that number below 14 days and also to reduce the percentage of contacts infected and researchers plan to analyze the results in 21 days. Around 200 patients with coronavirus and 3,000 of their close contacts will take part in the trial, which has private and public funding.

Source: https://www.reuters.com/

Mimicking Mosquito Eyes To Create Artificial Lens

Anyone who’s tried to swat a pesky mosquito knows how quickly the insects can evade a hand or fly swatter. The pests’ compound eyes, which provide a wide field of view, are largely responsible for these lightning-fast actions. Now, researchers reporting in ACS Applied Materials & Interfaces have developed compound lenses inspired by the mosquito eye that could someday find applications in autonomous vehicles, robots or medical devices.

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Compound eyes, found in most arthropods, consist of many microscopic lenses organized on a curved array. Each tiny lens captures an individual image, and the mosquito’s brain integrates all of the images to achieve peripheral vision without head or eye movement. The simplicity and multifunctionality of compound eyes make them good candidates for miniaturized vision systems, which could be used by drones or robots to rapidly image their surroundings. Joelle Frechette and colleagues from Johns Hopkins University wanted to develop a liquid manufacturing process to make compound lenses with most of the features of the mosquito eye.

To make each microlens, the researchers used a capillary microfluidic device to produce oil droplets surrounded by silica nanoparticles. Then, they organized many of these microlenses into a closely packed array around a larger oil droplet. They polymerized the structure with ultraviolet light to yield a compound lens with a viewing angle of 149 degrees, similar to that of the mosquito eye. The silica nanoparticles coating each microlens had antifogging properties, reminiscent of nanostructures on mosquito eyes that allow the insect organs to function in humid environments. The researchers could move, deform and relocate the fluid lenses, allowing them to create arrays of compound lenses with even greater viewing capabilities.

Source: https://www.acs.org/

Human Retinas Grown In A Dish

Biologists at Johns Hopkins University grew human retinas from scratch to determine how cells that allow people to see in color are made. The work, set for publication in the journal Science, lays the foundation to develop therapies for eye diseases such as color blindness and macular degeneration. It also establishes lab-created “organoids” as a model to study human development on a cellular level.

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Everything we examine looks like a normal developing eye, just growing in a dish,” said Robert Johnston, a developmental biologist at Johns Hopkins. “You have a model system that you can manipulate without studying humans directly.” Johnston’s lab explores how a cell’s fate is determined—or what happens in the womb to turn a developing cell into a specific type of cell, an aspect of human biology that is largely unknown. Here, he and his team focused on the cells that allow people to see blue, red and green—the three cone photoreceptors in the human eye.

While most vision research is done on mice and fish, neither of those species has the dynamic daytime and color vision of humans. So Johnston’s team created the human eye tissue they needed—with stem cells. “Trichromatic color vision differentiates us from most other mammals,” said lead author Kiara Eldred, a Johns Hopkins graduate student. “Our research is really trying to figure out what pathways these cells take to give us that special color vision.”

Source: https://hub.jhu.edu/

Electronic Skin To Restore Sense Of Pain

Amputees often experience the sensation of a “phantom limb”—a feeling that a missing body part is still there. That sensory illusion is closer to becoming a reality thanks to a team of engineers at the Johns Hopkins University that has created an electronic skin. When layered on top of prosthetic hands, this e-dermis brings back a real sense of touch through the fingertips.

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After many years, I felt my hand, as if a hollow shell got filled with life again,” says the anonymous amputee who served as the team’s principal volunteer tester.

Made of fabric and rubber laced with sensors to mimic nerve endings, e-dermis recreates a sense of touch as well as pain by sensing stimuli and relaying the impulses back to the peripheral nerves.

We’ve made a sensor that goes over the fingertips of a prosthetic hand and acts like your own skin would,” explains Luke Osborn, a graduate student in biomedical engineering. “It’s inspired by what is happening in human biology, with receptors for both touch and pain“This is interesting and new,” Osborn adds, “because now we can have a prosthetic hand that is already on the market and fit it with an e-dermis that can tell the wearer whether he or she is picking up something that is round or whether it has sharp points.”

The work in the journal Science Robotics – shows it is possible to restore a range of natural, touch-based feelings to amputees who use prosthetic limbs. The ability to detect pain could be useful, for instance, not only in prosthetic hands but also in lower limb prostheses, alerting the user to potential damage to the device.

Human skin contains a complex network of receptors that relay a variety of sensations to the brain. This network provided a biological template for the research team, which includes members from the Johns Hopkins departments of Biomedical Engineering, Electrical and Computer Engineering, and Neurology, and from the Singapore Institute of Neurotechnology.

Bringing a more human touch to modern prosthetic designs is critical, especially when it comes to incorporating the ability to feel pain, Osborn states. “Pain is, of course, unpleasant, but it’s also an essential, protective sense of touch that is lacking in the prostheses that are currently available to amputees,” he says. “Advances in prosthesis designs and control mechanisms can aid an amputee’s ability to regain lost function, but they often lack meaningful, tactile feedback or perception.

Source: http://releases.jhu.edu/

Mass Production of Low-Cost Solar Cells

An international team of university researchers today reports solving a major fabrication challenge for perovskite cells — the intriguing potential challengers to silicon-based solar cells.

These crystalline structures show great promise because they can absorb almost all wavelengths of light. Perovskite solar cells are already commercialized on a small scale, but recent vast improvements in their power conversion efficiency (PCE) are driving interest in using them as low-cost alternatives for solar panels.

In the cover article published online in Nanoscale, a publication of the Royal Society of Chemistry, the research team reveals a new scalable means of applying a critical component to perovskite cells to solve some major fabrication challenges. The researchers were able to apply the critical electron transport layer (ETL) in perovskite photovoltaic cells in a new way — spray coating — to imbue the ETL with superior conductivity and a strong interface with its neighbor, the perovskite layer.

The researchers turned to spray coating, which applies the ETL uniformly across a large area and is suitable for manufacturing large solar panels. They reported a 30 percent efficiency gain over other ETLs – from a PCE of 13 percent to over 17 percent – and fewer defects.

Added Taylor, “Our approach is concise, highly reproducible, and scalable. It suggests that spray coating the PCBM ETL could have broad appeal toward improving the efficiency baseline of perovskite solar cells and providing an ideal platform for record-breaking p-i-n perovskite solar cells in the near future.”

The research is led by André D. Taylor, an associate professor in the NYU Tandon School of Engineering’s Chemical and Biomolecular Engineering Department, with Yifan Zheng, the first author on the paper and a Peking University researcher. Co-authors are from the University of Electronic Science and Technology of China, Yale University, and Johns Hopkins University.

Source: https://engineering.nyu.edu/