Islands of cooperating atoms jam like ice floes as a liquid becomes like glass
We learn in school that matter comes in three states: solid, liquid and gas. A bored and clever student (we’ve all met one) then sometimes asks whether glass is a solid or a liquid.
The student has a point. Glasses are weird “solid liquids” that are cooled so fast their atoms or molecules jammed before organizing themselves in the regular patterns of a crystalline solid. So a glass has the mechanical properties of a solid but its atoms or molecules are disorganized, like those in a liquid.
One sign of the weirdness of glass is that the transition from liquid to a glass is much fuzzier than the transition from liquid to crystalline solid. In fact, the glass transition is arbitrarily... more
Bonded layers of rubber and hydrogel yield tough, slippery, and impermeable coatings.
Catheters, intravenous lines, and other types of surgical tubing are a medical necessity for managing a wide range of diseases. But a patient’s experience with such devices is rarely a comfortable one.
Now MIT engineers have designed a gel-like material that can be coated onto standard plastic or rubber devices, providing a softer, more slippery exterior that can significantly ease a patient’s discomfort. The coating can even be tailored to monitor and treat signs of infection.
In a paper published today in the journal Advanced Healthcare Materials, the team describes their method for strongly bonding a layer of hydrogel — a squishy, slippery polymer material that consists mostly... more
Supercapacitors are an aptly named type of device that can store and deliver energy faster than conventional batteries. They are in high demand for applications including electric cars, wireless telecommunications and high-powered lasers.
But to realize these applications, supercapacitors need better electrodes, which connect the supercapacitor to the devices that depend on their energy. These electrodes need to be both quicker and cheaper to make on a large scale and also able to charge and discharge their electrical load faster. A team of engineers at the University of Washington thinks they've come up with a process for manufacturing supercapacitor electrode materials that will meet these stringent industrial and usage demands.
The researchers, led by UW assistant professor of materials science and engineering Peter Pauzauskie, published a paper on July 17 in the journal Nature Microsystems and Nanoengineering describing... more
Timothy O'Connor/UC San Diego Jacobs School of Engineering
Engineers at the University of California San Diego have developed a smart glove that wirelessly translates the American Sign Language alphabet into text and controls a virtual hand to mimic sign language gestures.
The device, which engineers call “The Language of Glove,” was built for less than $100 using stretchable and printable electronics that are inexpensive, commercially available and easy to assemble. The work was published on July 12 in the journal PLOS ONE.
In addition to decoding American Sign Language gestures, researchers are developing the glove to be used in a variety of other applications ranging from virtual and augmented reality to telesurgery, technical training and defense.
“Gesture recognition is just one demonstration of this glove’s capabilities,” said Timothy O’Connor, a nanoengineering Ph.D. student at UC San Diego and the first author of the study. “Our ultimate... more
Rice researchers turn common insulator into a magnetic semiconductor
A little fluorine turns an insulating ceramic known as white graphene into a wide-bandgap semiconductor with magnetic properties. Rice University scientists said that could make the unique material suitable for electronics in extreme environments.
A proof-of-concept paper from Rice researchers demonstrates a way to turn two-dimensional hexagonal boron nitride (h-BN) – aka white graphene – from an insulator to a semiconductor. The magnetism, they said, is an unexpected bonus.
Because the atomically thin material is an exceptional conductor of heat, the researchers suggested it may be useful for electronics in high-temperature applications, perhaps even as magnetic memory devices... more
Novel theory developed by Pitt Chemical Engineering researchers explains how metal nanoparticles form
Although scientists have for decades been able to synthesize nanoparticles in the lab, the process is mostly trial and error, and how the formation actually takes place is obscure. However, a study recently published in Nature Communications by chemical engineers at the University of Pittsburgh’s Swanson School of Engineering explains how metal nanoparticles form.
“Thermodynamic Stability of Ligand-Protected Metal Nanoclusters” (DOI: 10.1038/ncomms15988) was co-authored by Giannis Mpourmpakis, assistant professor of chemical and petroleum engineering, and PhD candidate Michael G. Taylor. The research, completed in Mpourmpakis’ Computer-Aided Nano and Energy Lab (C.A.N.E.LA.), is... more
In the battle of the batteries, lithium-ion technology is the reigning champion, powering that cellphone in your pocket as well as an increasing number of electric vehicles on the road.
But a novel manganese and sodium-ion-based material developed at The University of Texas at Dallas, in collaboration with Seoul National University, might become a contender, offering a potentially lower-cost, more ecofriendly option to fuel next-generation devices and electric cars.
Battery cost is a substantial issue, said Dr. Kyeongjae Cho, professor of materials science and engineering in the Erik Jonsson School of Engineering and Computer Science and senior author of a paper describing the new material in the journal Advanced Materials.
As manufacturers — and consumers — push for more electric vehicles (EVs), lithium production may have a hard time keeping up with increasing... more
The Hong Kong Polytechnic University (PolyU) research team developed a novel breed of nanocomposites-inspired sensors which can be sprayed directly on flat or curved engineering structural surfaces, such as train tracks and aeroplane structures.
The sprayed sensors can be networked, to render rich real-time information on the health status of the structure under monitoring. Due to its light weight and low fabrication cost, large quantities of sensors can be deployed in a sensor network for detecting hidden flaws of structures, paving the way for a newera of ultrasonics-based structural health monitoring.
The nanocomposite sensors developed by the research team from PolyU's Department of Mechanical Engineering, led by Professor Su Zhongqing and Professor Zhou Limin, adopt an innovative technique of fabrication through spraying which makes installation process for sensors much faster and more efficient compared with conventional... more
University of Washington researchers have invented a cellphone that requires no batteries — a major leap forward in moving beyond chargers, cords and dying phones.
Instead, the phone harvests the few microwatts of power it requires from either ambient radio signals or light.
The team also made Skype calls using its battery-free phone, demonstrating that the prototype made of commercial, off-the-shelf components can receive and transmit speech and communicate with a base station.
The new technology is detailed in a paper published July 1 in the Proceedings of the Association for Computing Machinery on Interactive, Mobile, Wearable and Ubiquitous Technologies.
“We’ve built what we believe is the first functioning cellphone that consumes almost zero power,” said co-author Shyam Gollakota, an associate professor in the Paul G. Allen School of... more
A research group from the Institute of Process Engineering (IPE) of the Chinese Academy of Sciences recently reported the development of a new technology to boost performance of direct methanol fuel cells (DMFCs) using high-concentration methanol as fuel, shedding some light on the design of clean and affordable alternative energy sources for portable electric devices.
When methanol, the fuel of DMFCs, crosses over from the anode to the cathode through the proton exchange membrane (PEM), fuel cell performance is significantly degraded, creating a major problem for the commercialization of DMFCs. Commonly, scientists use various strategies to improve DMFC performance at high concentrations of methanol. These include improving the fuel-feed system, membrane development, modification of electrodes, and water management.
"These conventional strategies do not fundamentally overcome the key obstacle, but inevitably complicate the design of DMFCs and hence increase their cost," said YANG Jun, an IPE professor. Working with FENG Yan, a doctoral student... more