A collaborative team of researchers from Shinshu University in Japan have found a new way to curb some of the potential dangers posed by lithium ion batteries.

The team was led by Susumu Arai, a professor of the department of materials chemistry and head of Division for Application of Carbon Materials at the Institute of Carbon Science and Technology at Shinshu University.

These batteries, typically used in electric vehicles and smart grids, could help society realize a low-carbon future, according the authors. The problem is that while lithium could theoretically conduct electricity at high capacity, lithium also results in what is known as thermal runaway during the charge and discharge cycle.

“Lithium metal is inherently unsuitable for use in rechargeable batteries due to posing certain safety risks,” said Arai. “Repeated lithium deposition/dissolution during charge/discharge can cause serious accidents due to the deposition of lithium dendrites that penetrate the separator and induce internal short-circuiting.”

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Deadline Extended: March 19, 2018

The “Semiconductor-Based Sensors for Application to Vapors, Chemicals, Biological Species, and Medical Diagnosis” focus issue of the ECS Journal of Solid State Science and Technology aims to cover various active or passive semiconductor devices for gas, chemical, bio and medical detection, with the focus on silicon, GaN, dichalcogenides/oxides, graphene, and other semiconductor materials for electronic or photonic devices.

The scope of contributed articles includes materials preparation, growth, processing, devices, chemistry, physics, theory, and applications for the semiconductor sensors. Different methodologies, principles, designs, models, fabrication techniques, and characterization are all included. Integrated systems combine semiconductor sensors, electric circuit, microfluidic channels, display, and control unit for real applications such as disease diagnostic or environmental monitoring are also welcome.

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By: Srikanth Saripalli, Texas A&M University

Image: CC0 Public Domain

What should a self-driving car do when a nearby vehicle is swerving unpredictably back and forth on the road, as if its driver were drunk? What about encountering a vehicle driving the wrong way? Before autonomous cars are on the road, everyone should know how they’ll respond in unexpected situations.

I develop, test and deploy autonomous shuttles, identifying methods to ensure self-driving vehicles are safe and reliable. But there’s no testing track like the country’s actual roads, and no way to test these new machines as thoroughly as modern human-driven cars have been, with trillions of miles driven every year for decades. When self-driving cars do hit the road, they crash in ways both serious and minor. Yet all their decisions are made electronically, so how can people be confident they’re driving safely?

Fortunately, there’s a common, popular and well-studied method to ensure new technologies are safe and effective for public use: The testing system for new medications. The basic approach involves ensuring these systems do what they’re intended to, without any serious negative side effects – even if researchers don’t fully understand how they work.

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Engineers have, for the first time, come up with a way to safely charge a smartphone wirelessly using a laser.

A narrow, invisible beam from a laser emitter can deliver charge to a smartphone sitting across a room—and potentially charge the phone’s battery as quickly as a standard USB cable.

To accomplish this, the researchers mounted a thin power cell to the back of a smartphone, which charges the smartphone using power from the laser.

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Top 6 reasons to attend the next ECS meeting

ECS biannual meetings are a forum for sharing the latest scientific and technical developments in electrochemistry and solid state science and technology. Scientists, engineers and industry leaders come from around the world to attend the technical symposia, poster sessions, and professional development workshops. Not to mention exciting networking opportunities and social events.

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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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A new process for growing wafer-scale 2D crystals could enable future super-thin electronics.

Since the discovery of the remarkable properties of graphene, scientists have increasingly focused research on the many other two-dimensional materials possible, both those found in nature and those concocted in the lab.

Growing high-quality, crystalline 2D materials at scale, however, has proven a significant challenge.

Researchers led by Joan Redwing, director of the National Science Foundation-sponsored Two-Dimensional Crystal Consortium—Materials Innovation Platform, and professor of materials science and engineering and electrical engineering at Penn State, developed a multistep process to make single crystal, atomically thin films of tungsten diselenide across large-area sapphire substrates.

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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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Stress a muscle and it gets stronger. Mechanically stress a new rubbery material—say with a twist or a bend—and it automatically stiffens by up to 300 percent, the engineers say.

In lab tests, mechanical stresses transformed a flexible strip of the material into a hard composite that can support 50 times its own weight.

This new composite material doesn’t need outside energy sources such as heat, light, or electricity to change its properties. And it could be used in a variety of ways, including applications in medicine and industry.

The researchers found a simple, low-cost way to produce particles of undercooled metal—that’s metal that remains liquid even below its melting temperature. Researchers created the tiny particles (they’re just 1 to 20 millionths of a meter across) by exposing droplets of melted metal to oxygen, creating an oxidation layer that coats the droplets and stops the liquid metal from turning solid. They also found ways to mix the liquid-metal particles with a rubbery elastomer material without breaking the particles.

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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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