Engineers are developing a new method of processing nanomaterials that could lead to faster and cheaper manufacturing of flexible, thin film devices, such as touch screens and window coatings.

The “intense pulsed light sintering” method uses high-energy light over an area nearly 7,000 times larger than a laser to fuse nanomaterials in seconds.

The existing method of pulsed light fusion uses temperatures of around 250 degrees Celsius (482 degrees Fahrenheit) to fuse silver nanospheres into structures that conduct electricity. But the new study, published in RSC Advances and led by Rutgers School of Engineering doctoral student Michael Dexter, shows that fusion at 150 degrees Celsius (302 degrees Fahrenheit) works well while retaining the conductivity of the fused silver nanomaterials.

The engineers’ achievement started with silver nanomaterials of different shapes: long, thin rods called nanowires in addition to nanospheres. The sharp reduction in temperature needed for fusion makes it possible to use low-cost, temperature-sensitive plastic substrates like polyethylene terephthalate (PET) and polycarbonate in flexible devices without damaging them.

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The portable biosensor can test specific cardiac markers in five minutes with a single drop of blood.
Credit: Yu-Lin Wang

A team of researchers from National Tsing Hua University and National Cheng Kung University, both in Taiwan, has developed a low-cost, portable medical sensor package that has the potential to alert users of medical issues ranging from severe heart conditions to cancer, according to a new study published in the ECS Journal of Solid State Science and Technology.

Portable medical devices have become an integral part of holistic health care, exhibiting huge potential in monitoring, medical therapeutics, diagnosis, and fitness and wellness. When paired with benchtop point-of-care instruments used in hospitals and urgent care centers, individuals are able to both increase preventative care measures and gain a more complete picture of their health.

According to the open access paper, “Field-Effect Transistor-Based Biosensors and a Portable Device for Personal Healthcare” (ECS J. Solid State Sci. Technol., 6, Q71 [2017]), researchers have reported the design, development, fabrication, and prototyping of a low-cost transistor-based device that can measure the C-reactive protein (CRP) in bloodstreams, which, when elevated, indicates inflammation that could be linked to heart attack, stroke, coronary artery disease, and a host of other medical diagnosis.

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Researchers have developed a new titanium-based material that is a good candidate for making lead-free, inorganic perovskite solar cells.

In a new paper, which appears in the journal Joule, the researchers show that the material is especially good for making tandem solar cells—arrangements in which a perovskite cells are placed on top of silicon or another established material to boost the overall efficiency.

Perovskites have emerged as a promising alternative to silicon for making inexpensive and efficient solar cells. But for all their promise, perovskites are not without their downsides. Most contain lead, which is highly toxic, and include organic materials that are not particularly stable when exposed to the environment.

“Titanium is an abundant, robust, and biocompatible element that, until now, has been largely overlooked in perovskite research,” says senior author Nitin Padture, professor of engineering and director of the Institute for Molecular and Nanoscale Innovation.

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Scientists who introduced laser-induced graphene (LIG) enhanced their technique to produce what may become a new class of edible electronics.

The chemists, who once turned Girl Scout cookies into graphene, are investigating ways to write graphene patterns onto food and other materials to quickly embed conductive identification tags and sensors into the products themselves.

“This is not ink,” says James Tour, chair of chemistry and professor of computer science and of materials science and nanoengineering at Rice University. “This is taking the material itself and converting it into graphene.”

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In a recently published ECS Journal of Solid State Science and Technology paper, ECS member Roger Loo and coauthors describe a new epitaxial growth technology and address the challenges of implementation. The open access article, “Epitaxial CVD Growth of Ultra-Thin Si Passivation Layers on Strained Ge Fin Structures,” was designated Editors’ Choice due to its significance and the importance of the technology described.

“The work combines carefully thought out and elegant experimental work, with appropriate simulation work that compliments the experiments,” said Jennifer Bardwell, ECS Journal of Solid State Science and Technology technical editor in the area of electronic materials and processing. “I am certain that it will be of great interest to many of our readers.”

We recently sat down with Loo to discuss the work and its impact on the field.

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By: Jaci VanHeest, University of Connecticut

As Fitbits and other wearable activity monitors change how regular people exercise and track their activity, they’re having similar effects on how Olympians train and recover between workouts.

It’s long been common for coaches to use video cameras to show athletes what their form and movements look like, to track progress, and to fine-tune exactly the right technique for, say, taking off for a jump or landing after a particular trick. But those only show what’s going on from the outside.

Now, wearables, biometrics and apps analyzing their data are becoming much more common for athletes at all levels, giving indications of what’s going on inside an athlete’s body. I have worked as a sport physiologist with elite athletes for two decades, including with USA Swimming and U.S. Figure Skating; there’s not yet much research about the results in figure skating, but wearables have helped coaches, athletes and sport scientists in other sports like swimming, cycling, soccer and volleyball.

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Engineers used tissue paper—similar to toilet tissue—to make a new kind of wearable sensor that can detect a pulse or a blink of an eye.

The sensor, which is light, flexible, and inexpensive, could be used for health care, entertainment, and robotics, researchers say.

Tearing tissue paper that’s loaded with nanocomposites and breaking the paper’s fibers makes the paper acts like a sensor. It can detect a heartbeat, finger force, finger movement, eyeball movement, and more, says Jae-Hyun Chung, an associate professor of mechanical engineering at the University of Washington and senior author of the paper in Advanced Materials Technologies.

“The major innovation is a disposable wearable sensor made with cheap tissue paper. When we break the specimen, it will work as a sensor.”

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A small metallic tab that, when attached to the body, is capable of generating electricity from bending a finger and other simple movements could one day power our electronic devices.

“No one likes being tethered to a power outlet or lugging around a portable charger. The human body is an abundant source of energy. We thought: ‘Why not harness it to produce our own power?’” says Qiaoqiang Gan, associate professor of electrical engineering in the School of Engineering and Applied Sciences at the University at Buffalo and lead author of a paper describing the tab in the journal Nano Energy.

The tab is a triboelectric nanogenerator. Triboelectric charging occurs when certain materials become electrically charged after coming into contact with a different material. Most everyday static electricity is triboelectric.

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Researchers may have found a way to solve the weakness of a type of light source similar to lasers. The alternative light source could lead to smaller, lower-cost, and more efficient sources of light pulses.

Although critical for varied applications, such as cutting and welding, surgery and transmitting bits through optical fiber, lasers have some limitations—namely, they only produce light in limited wavelength ranges.

Now, researchers have modified similar light sources, called optical parametric oscillators, to overcome this obstacle.

Until now, these lesser-known light sources have been mostly confined to the lab because their setup leaves little room for error—even a minor jostle could knock one out of alignment.

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By: Peter Hancock, University of Central Florida

Much of the push toward self-driving cars has been underwritten by the hope that they will save lives by getting involved in fewer crashes with fewer injuries and deaths than human-driven cars. But so far, most comparisons between human drivers and automated vehicles have been at best uneven, and at worst, unfair.

The statistics measuring how many crashes occur are hard to argue with: More than 90 percent of car crashes in the U.S. are thought to involve some form of driver error. Eliminating this error would, in two years, save as many people as the country lost in all of the Vietnam War.

But to me, as a human factors researcher, that’s not enough information to properly evaluate whether automation may actually be better than humans at not crashing. Their respective crash rates can only be determined by also knowing how many non-collisions happen. For human drivers is it one collision per billion chances to crash, or one in a trillion?

Assessing the rate at which things do not happen is extremely difficult. For example, estimating how many times you didn’t bump into someone in the hall today relates to how many people there were in the hallway and how long you were walking there. Also, people forget non-events very quickly, if we even notice them happening. To determine whether automated vehicles are safer than humans, researchers will need to establish a non-collision rate for both humans and these emerging driverless vehicles.

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