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Nordson MARCH, a Nordson company (NASDAQ:NDSN), a developer of plasma processing technology, introduces the MesoSPHERE Plasma System for very-high throughput processing of 3D and wafer-level packaging processes such as fan-in, fan-out, wafer-level, and panel-level – handling wafers up to 450mm and panels up to 480mm. The MesoSPHERE’s new, patented W3 three-axis symmetrical plasma chamber ensures that all areas of the wafer are treated equally and uniformly. Tight control over all process parameters gives highly repeatable results.

For wafer cleaning, the MesoSPHERE plasma system removes contamination prior to wafer bumping, organic contamination, fluorine and other halogen contamination, and metal and metal oxides. Plasma improves spun-on film adhesion and cleans metallic bond pads.

For wafer etching, the MesoSPHERE plasma system descums wafers of residual photoresist and BCB, pattern dielectric layers for redistribution, strip/etch photoresist, enhances adhesion of wafer applied materials, removes excess wafer applied mold /epoxy, enhances adhesion of gold solder bumps, destresses wafer to reduce breakage, improves spun-on film adhesion, and cleans aluminum bond pads.

The MesoSPHERE’s chamber design and control architecture enable short plasma cycle times with very low overhead, maximizing throughput and minimizing cost of ownership. Plasma confinement technology uses a ring to isolate and focus plasma so it’s distributed directly above the wafer, minimizing undesired secondary reactions. Process temperatures can be kept low because the ring increases etch rate capability without increasing the electrode temperature or adding bias to the chuck.

An innovative handling system transfers round or square substrates and frame or bonded carriers. The modular design allows capacity increase on a per plasma chamber basis. Equipment front end module (EFEM) integration supports from 1 to 4 plasma chambers. A pocket chuck design provides accurate substrate placement and centering, for additional process repeatability.

“A unique feature of the MesoSPHERE is the way we developed the isolation,” explained Jonathan Doan, director of marketing for Nordson MARCH. “It allows our customers a method to perform advanced packaging without having to use an expensive carrier and it can be used with 300mm wafers on frames.”

Nowadays, zinc oxide nanoparticles are one of the most commonly used nanomaterials. They seem to be safe for humans, but there are still no standards for their toxicity and despite intense investigations, the toxicological impact of ZnO nanomaterials still remains ambiguous. Researchers from the Institute of Physical Chemistry of the Polish Academy of Sciences (IPC PAS) in Warsaw and the Faculty of Chemistry of the Warsaw University of Technology (PW) have recently developed a method for producing defect-free ZnO quantum dots with physicochemical properties that are particularly interesting and do not change over time, such as monodispersity, a relatively high quantum efficiency, record-long luminescence lifetimes and EPR silence under standard conditions. The unique features of the tightly coordinated and impermeable organic shells stabilizing the surface make the new ZnO quantum dots resistant to both chemical and biological environments.

“The zinc oxide nanocrystals of unprecedented high quality obtained by us are characterized by significantly better chemical and physical properties than their counterparts currently being produced by the most popular sol-gel method involving inorganic precursors”, emphasizes Prof. Janusz Lewinski (IPC PAS, PW). “The luminescence lifetime, or luminance, in the case of our quantum dots is much longer – by even up to several orders of magnitude! Moreover, until now only short ZnO photoluminescence decays have been observed, of the order of a few to a dozen-or-so picoseconds characteristic for sol-gel nanoparticles, or slightly longer, nanosecond ones, typical only for ZnO monocrystals. What we have is a luminescent material that can be used, for example, as a new generation optical marker for biomedical applications.”

Combined with biologically active molecules, the new nanoparticles could be used in biology or medicine, e.g. for imaging cells and tissues, which would enable much more accurate monitoring of disease development and efficacy of treatment. In a recent publication in the well-known scientific journal Chemistry – A European Journal, the Warsaw scientists, in collaboration with a group from the Jagiellonian University in Cracow, showed that their zinc oxide nanoparticles are indeed safe. The research, funded by the TEAM grant from the Foundation for Polish Science and the OPUS grant of the Polish National Science Centre, allows us to realistically think about rapid introduction of the new ZnO quantum dots into, among others, biological and medical laboratories.

ZnO nanocrystals manufactured in a classic manner by the sol-gel method are not well stabilized or isolated from the environment. For example, interactions that occur at the interface between the inorganic ZnO core and the biological environment can lead to the generation of reactive oxygen species or the dissolution and release of potentially toxic zinc cations.

“Zinc oxide is generally considered as a relatively safe and biocompatible material. However, many toxicological studies of ZnO concern nanoparticles that are heterogeneous in size and also too large to be able to penetrate into cells. We also realized that in practice many of the characteristics of nanoparticles depend not only on their size, but also on the surface properties of both the nanocrystalline ZnO and the organic stabilizing layer. Therefore, we decided to modify our one-pot self-supporting organometallic method of synthesis, so that the ZnO nanoparticles resulting from it behave as neutrally as possible in the interior of the cells,” explains Dr. Malgorzata Wolska-Pietkiewicz (PW).

Prof. Lewinski’s team produces quantum dots of zinc oxide from organometallic compounds (precursors). When the purpose is biological applications, the end result is stable nanoparticles with a shape that is similar to a sphere, consisting of a crystalline ZnO core with a diameter of 4-5 nanometres surrounded by a shell of organic ligands. This shell increases the size of the nanoparticles (their hydrodynamic diameter is about 12 nm) and has protective functions: on the one hand it protects the inorganic core from degradation due to interaction with what is often a very reactive biological environment, on the other hand it eliminates the influence of ZnO itself on this environment.

“Nanoparticles with core sizes below 10 nm penetrate inside the cells particularly easily. Such particles are considered to be potentially the most toxic. Interestingly, the ZnO nanoparticles created by us, contrary to popular opinion indicating that the smaller the systems, the greater their toxicity, showed extremely low harmful effects in in vitro model tests. The recent results as well as the studies carried out simultaneously in the parent team provided further evidence of the unique character of the nanocrystalline ZnO obtained as a result of the transformation of organometallic molecular precursors,” notes Dr. Wolska-Pietkiewicz.

The research on ZnO quantum dots gives hope for numerous applications. However, there are concerns about their biological and environmental impacts. Nanoparticles can enter the body and among others, the respiratory tract is frequently exposed to elevated concentrations of different nanomaterials and becomes the primary target site for toxicity. Therefore, A549 and MRC-5 cell lines were selected as in vitro models for internal malignancies and normal lung cells, respectively. Researchers from the IPC PAS and PW showed that the organic layer surrounding the improved nanoparticles is indeed impermeable: zinc ions are not released into the environment, and reactive oxygen species are not formed. Even at high concentrations, the toxicity of the new ZnO nanoparticles turned out to be negligible.

“Our ‘recipe’ for the production of ZnO quantum dots means that they simply do not interact with the biological environment. So we have a strong foundation on which to start working on their applications. Not only in medical imaging, but also in other areas in which nanoparticles could potentially interact with the human body, for example, as one of the components of paint. We are also developing a new technology for the synthesis of ZnO quantum dots and searching for potential applications as a part of NANOXO, a start-up company”, summarizes Prof. Lewinski.

The end of the silicon age has begun. As computer chips approach the physical limits of miniaturization and power-hungry processors drive up energy costs, scientists are looking to a new crop of exotic materials that could foster a new generation of computing devices that promise to push performance to new heights while skimping on energy consumption.

Unlike current silicon-based electronics, which shed most of the energy they consume as waste heat, the future is all about low-power computing. Known as spintronics, this technology relies on a quantum physical property of electrons — up or down spin — to process and store information, rather than moving them around with electricity as conventional computing does.

On the quest to making spintronic devices a reality, scientists at the University of Arizona are studying an exotic crop of materials known as transition metal dichalcogenides, or TMDs. TMDs have exciting properties lending themselves to new ways of processing and storing information and could provide the basis of future transistors and photovoltaics — and potentially even offer an avenue toward quantum computing.

For example, current silicon-based solar cells convert realistically only about 25 percent of sunlight into electricity, so efficiency is an issue, says Calley Eads, a fifth-year doctoral student in the UA’s Department of Chemistry and Biochemistry who studies some of the properties of these new materials. “There could be a huge improvement there to harvest energy, and these materials could potentially do this,” she says.

There is a catch, however: Most TMDs show their magic only in the form of sheets that are very large, but only one to three atoms thin. Such atomic layers are challenging enough to manufacture on a laboratory scale, let alone in industrial mass production.

Many efforts are underway to design atomically thin materials for quantum communication, low-power electronics and solar cells, according to Oliver Monti, a professor in the department and Eads’ adviser. Studying a TMD consisting of alternating layers of tin and sulfur, his research team recently discovered a possible shortcut, published in the journal Nature Communications.

“We show that for some of these properties, you don’t need to go to the atomically thin sheets,” he says. “You can go to the much more readily accessible crystalline form that’s available off the shelf. Some of the properties are saved and survive.”

Understanding electron movement

This, of course, could dramatically simplify device design.

“These materials are so unusual that we keep discovering more and more about them, and they are revealing some incredible features that we think we can use, but how do we know for sure?” Monti says. “One way to know is by understanding how electrons move around in these materials so we can develop new ways of manipulating them — for example, with light instead of electrical current as conventional computers do.”

To do this research, the team had to overcome a hurdle that never had been cleared before: figure out a way to “watch” individual electrons as they flow through the crystals.

“We built what is essentially a clock that can time moving electrons like a stopwatch,” Monti says. “This allowed us to make the first direct observations of electrons move in crystals in real time. Until now, that had only been done indirectly, using theoretical models.”

The work is an important step toward harnessing the unusual features that make TMDs intriguing candidates for future processing technology, because that requires a better understanding of how electrons behave and move around in them.

Monti’s “stopwatch” makes it possible to track moving electrons at a resolution of a mere attosecond — a billionth of a billionth of a second. Tracking electrons inside the crystals, the team made another discovery: The charge flow depends on direction, an observation that seems to fly in the face of physics.

Collaborating with Mahesh Neupane, a computational physicist at Army Research Laboratories, and Dennis Nordlund, an X-ray spectroscopy expert at Stanford University’s SLAC National Accelerator Laboratory, Monti’s team used a tunable, high-intensity X-ray source to excite individual electrons in their test samples and elevate them to very high energy levels.

“When an electron is excited in that way, it’s the equivalent of a car that is being pushed from going 10 miles per hour to thousands of miles per hour,” Monti explains. “It wants to get rid of that enormous energy and fall back down to its original energy level. That process is extremely short, and when that happens, it gives off a specific signature that we can pick up with our instruments.”

The researchers were able to do this in a way that allowed them to distinguish whether the excited electrons stayed within the same layer of the material, or spread into adjacent layers across the crystal.

“We saw that electrons excited in this way scattered within the same layer and did so extremely fast, on the order of a few hundred attoseconds,” Monti says.

In contrast, electrons that did cross into adjacent layers took more than 10 times longer to return to their ground energy state. The difference allowed the researchers to distinguish between the two populations.

“I was very excited to find that directional mechanism of charge distribution occurring within a layer, as opposed to across layers,” says Eads, the paper’s lead author. “That had never been observed before.”

Closer to mass manufacturing

The X-ray “clock” used to track electrons is not part of the envisioned applications but a means to study the behavior of electrons inside them, Monti explains, a necessary first step in getting closer toward technology with the desired properties that could be mass-manufactured.

“One example of the unusual behavior we see in these materials is that an electron going to the right is not the same as an electron going to the left,” he says. “That shouldn’t happen — according to physics of standard materials, going to the left or the right is the exact same thing. However, for these materials that is not true.”

This directionality is an example of what makes TMDs intriguing to scientists, because it could be used to encode information.

“Moving to the right could be encoded as ‘one’ and going to the left as ‘zero,'” Monti says. “So if I can generate electrons that neatly go to the right, I’ve written a bunch of ones, and if I can generate electrons that neatly go to the left, I have generated a bunch of zeroes.”

Instead of applying electrical current, engineers could manipulate electrons in this way using light such as a laser, to optically write, read and process information. And perhaps someday it may even become possible to optically entangle information, clearing the way to quantum computing.

“Every year, more and more discoveries are occurring in these materials,” Eads says. “They are exploding in terms of what kinds of electronic properties you can observe in them. There is a whole spectrum of ways in which they can function, from superconducting, semiconducting to insulating, and possibly more.”

The research described here is just one way of probing the unexpected, exciting properties of layered TMD crystals, according to Monti.

“If you did this experiment in silicon, you wouldn’t see any of this,” he says. “Silicon will always behave like a three-dimensional crystal, no matter what you do. It’s all about the layering.”

Engineers at the University of California, Riverside, have reported advances in so-called “spintronic” devices that will help lead to a new technology for computing and data storage. They have developed methods to detect signals from spintronic components made of low-cost metals and silicon, which overcomes a major barrier to wide application of spintronics. Previously such devices depended on complex structures that used rare and expensive metals such as platinum. The researchers were led by Sandeep Kumar, an assistant professor of mechanical engineering.

UCR researchers have developed methods to detect signals from spintronic components made of low-cost metals and silicon. Credit: UC Riverside

UCR researchers have developed methods to detect signals from spintronic components made of low-cost metals and silicon. Credit: UC Riverside

Spintronic devices promise to solve major problems in today’s electronic computers, in that the computers use massive amounts of electricity and generate heat that requires expending even more energy for cooling. By contrast, spintronic devices generate little heat and use relatively minuscule amounts of electricity. Spintronic computers would require no energy to maintain data in memory. They would also start instantly and have the potential to be far more powerful than today’s computers.

While electronics depends on the charge of electrons to generate the binary ones or zeroes of computer data, spintronics depends on the property of electrons called spin. Spintronic materials register binary data via the “up” or “down” spin orientation of electrons–like the north and south of bar magnets–in the materials. A major barrier to development of spintronics devices is generating and detecting the infinitesimal electric spin signals in spintronic materials.

In one paper published in the January issue of the scientific journal Applied Physics Letters, Kumar and colleagues reported an efficient technique of detecting the spin currents in a simple two-layer sandwich of silicon and a nickel-iron alloy called Permalloy. All three of the components are both inexpensive and abundant and could provide the basis for commercial spintronic devices. They also operate at room temperature. The layers were created with the widely used electronics manufacturing processes called sputtering. Co-authors of the paper were graduate students Ravindra Bhardwaj and Paul Lou.

In their experiments, the researchers heated one side of the Permalloy-silicon bi-layer sandwich to create a temperature gradient, which generated an electrical voltage in the bi-layer. The voltage was due to phenomenon known as the spin-Seebeck effect. The engineers found that they could detect the resulting “spin current” in the bi-layer due to another phenomenon known as the “inverse spin-Hall effect.”

The researchers said their findings will have application to efficient magnetic switching in computer memories, and “these scientific breakthroughs may give impetus” to development of such devices. More broadly, they concluded, “These results bring the ubiquitous Si (silicon) to forefront of spintronics research and will lay the foundation of energy efficient Si spintronics and Si spin caloritronics devices.”

In two other scientific papers, the researchers demonstrated that they could generate a key property for spintronics materials, called antiferromagnetism, in silicon. The achievement opens an important pathway to commercial spintronics, said the researchers, given that silicon is inexpensive and can be manufactured using a mature technology with a long history of application in electronics.

Ferromagnetism is the property of magnetic materials in which the magnetic poles of the atoms are aligned in the same direction. In contrast, antiferromagnetism is a property in which the neighboring atoms are magnetically oriented in opposite directions. These “magnetic moments” are due to the spin of electrons in the atoms, and is central to the application of the materials in spintronics.

In the two papers, Kumar and Lou reported detecting antiferromagnetism in the two types of silicon–called n-type and p-type–used in transistors and other electronic components. N-type semiconductor silicon is “doped” with substances that cause it to have an abundance of negatively-charged electrons; and p-type silicon is doped to have a large concentration of positively charged “holes.” Combining the two types enables switching of current in such devices as transistors used in computer memories and other electronics.

In the paper in the Journal of Magnetism and Magnetic Materials, Lou and Kumar reported detecting the spin-Hall effect and antiferromagnetism in n-silicon. Their experiments used a multilayer thin film comprising palladium, nickel-iron Permalloy, manganese oxide and n-silicon.

And in the second paper, in the scientific journal physica status solidi, they reported detecting in p-silicon spin-driven antiferromagnetism and a transition of silicon between metal and insulator properties. Those experiments used a thin film similar to those with the n-silicon.

The researchers wrote in the latter paper that “The observed emergent antiferromagnetic behavior may lay the foundation of Si (silicon) spintronics and may change every field involving Si thin films. These experiments also present potential electric control of magnetic behavior using simple semiconductor electronics physics. The observed large change in resistance and doping dependence of phase transformation encourages the development of antiferromagnetic and phase change spintronics devices.”

In further studies, Kumar and his colleagues are developing technology to switch spin currents on and off in the materials, with the ultimate goal of creating a spin transistor. They are also working to generate larger, higher-voltage spintronic chips. The result of their work could be extremely low-power, compact transmitters and sensors, as well as energy-efficient data storage and computer memories, said Kumar.

When it comes to processing power, the human brain just can’t be beat.

Packed within the squishy, football-sized organ are somewhere around 100 billion neurons. At any given moment, a single neuron can relay instructions to thousands of other neurons via synapses — the spaces between neurons, across which neurotransmitters are exchanged. There are more than 100 trillion synapses that mediate neuron signaling in the brain, strengthening some connections while pruning others, in a process that enables the brain to recognize patterns, remember facts, and carry out other learning tasks, at lightning speeds.

Researchers in the emerging field of “neuromorphic computing” have attempted to design computer chips that work like the human brain. Instead of carrying out computations based on binary, on/off signaling, like digital chips do today, the elements of a “brain on a chip” would work in an analog fashion, exchanging a gradient of signals, or “weights,” much like neurons that activate in various ways depending on the type and number of ions that flow across a synapse.

In this way, small neuromorphic chips could, like the brain, efficiently process millions of streams of parallel computations that are currently only possible with large banks of supercomputers. But one significant hangup on the way to such portable artificial intelligence has been the neural synapse, which has been particularly tricky to reproduce in hardware.

Now engineers at MIT have designed an artificial synapse in such a way that they can precisely control the strength of an electric current flowing across it, similar to the way ions flow between neurons. The team has built a small chip with artificial synapses, made from silicon germanium. In simulations, the researchers found that the chip and its synapses could be used to recognize samples of handwriting, with 95 percent accuracy.

The design, published today in the journal Nature Materials, is a major step toward building portable, low-power neuromorphic chips for use in pattern recognition and other learning tasks.

The research was led by Jeehwan Kim, the Class of 1947 Career Development Assistant Professor in the departments of Mechanical Engineering and Materials Science and Engineering, and a principal investigator in MIT’s Research Laboratory of Electronics and Microsystems Technology Laboratories. His co-authors are Shinhyun Choi (first author), Scott Tan (co-first author), Zefan Li, Yunjo Kim, Chanyeol Choi, and Hanwool Yeon of MIT, along with Pai-Yu Chen and Shimeng Yu of Arizona State University.

Too many paths

Most neuromorphic chip designs attempt to emulate the synaptic connection between neurons using two conductive layers separated by a “switching medium,” or synapse-like space. When a voltage is applied, ions should move in the switching medium to create conductive filaments, similarly to how the “weight” of a synapse changes.

But it’s been difficult to control the flow of ions in existing designs. Kim says that’s because most switching mediums, made of amorphous materials, have unlimited possible paths through which ions can travel — a bit like Pachinko, a mechanical arcade game that funnels small steel balls down through a series of pins and levers, which act to either divert or direct the balls out of the machine.

Like Pachinko, existing switching mediums contain multiple paths that make it difficult to predict where ions will make it through. Kim says that can create unwanted nonuniformity in a synapse’s performance.

“Once you apply some voltage to represent some data with your artificial neuron, you have to erase and be able to write it again in the exact same way,” Kim says. “But in an amorphous solid, when you write again, the ions go in different directions because there are lots of defects. This stream is changing, and it’s hard to control. That’s the biggest problem — nonuniformity of the artificial synapse.”

A perfect mismatch

Instead of using amorphous materials as an artificial synapse, Kim and his colleagues looked to single-crystalline silicon, a defect-free conducting material made from atoms arranged in a continuously ordered alignment. The team sought to create a precise, one-dimensional line defect, or dislocation, through the silicon, through which ions could predictably flow.

To do so, the researchers started with a wafer of silicon, resembling, at microscopic resolution, a chicken-wire pattern. They then grew a similar pattern of silicon germanium — a material also used commonly in transistors — on top of the silicon wafer. Silicon germanium’s lattice is slightly larger than that of silicon, and Kim found that together, the two perfectly mismatched materials can form a funnel-like dislocation, creating a single path through which ions can flow.

The researchers fabricated a neuromorphic chip consisting of artificial synapses made from silicon germanium, each synapse measuring about 25 nanometers across. They applied voltage to each synapse and found that all synapses exhibited more or less the same current, or flow of ions, with about a 4 percent variation between synapses — a much more uniform performance compared with synapses made from amorphous material.

They also tested a single synapse over multiple trials, applying the same voltage over 700 cycles, and found the synapse exhibited the same current, with just 1 percent variation from cycle to cycle.

“This is the most uniform device we could achieve, which is the key to demonstrating artificial neural networks,” Kim says.

Writing, recognized

As a final test, Kim’s team explored how its device would perform if it were to carry out actual learning tasks — specifically, recognizing samples of handwriting, which researchers consider to be a first practical test for neuromorphic chips. Such chips would consist of “input/hidden/output neurons,” each connected to other “neurons” via filament-based artificial synapses.

Scientists believe such stacks of neural nets can be made to “learn.” For instance, when fed an input that is a handwritten ‘1,’ with an output that labels it as ‘1,’ certain output neurons will be activated by input neurons and weights from an artificial synapse. When more examples of handwritten ‘1s’ are fed into the same chip, the same output neurons may be activated when they sense similar features between different samples of the same letter, thus “learning” in a fashion similar to what the brain does.

Kim and his colleagues ran a computer simulation of an artificial neural network consisting of three sheets of neural layers connected via two layers of artificial synapses, the properties of which they based on measurements from their actual neuromorphic chip. They fed into their simulation tens of thousands of samples from a handwritten recognition dataset commonly used by neuromorphic designers, and found that their neural network hardware recognized handwritten samples 95 percent of the time, compared to the 97 percent accuracy of existing software algorithms.

The team is in the process of fabricating a working neuromorphic chip that can carry out handwriting-recognition tasks, not in simulation but in reality. Looking beyond handwriting, Kim says the team’s artificial synapse design will enable much smaller, portable neural network devices that can perform complex computations that currently are only possible with large supercomputers.

“Ultimately we want a chip as big as a fingernail to replace one big supercomputer,” Kim says. “This opens a stepping stone to produce real artificial hardware.”

This research was supported in part by the National Science Foundation.

A crystal method


January 31, 2018

From Mother Nature to our must-have devices, we’re surrounded by crystals. Those courtesy of the former, such as ice and snow, can form spontaneously and symmetrically. But the silicon-based or gallium nitride crystals found in LEDs and other electronics require a bit of coaxing to attain their ideal shapes and alignments.

At UC Santa Barbara, researchers have now unlocked another piece of the theoretical puzzle that governs the growth of crystals — a development that may save time and energy in the many processes that require crystal formation.

“The way most industrial processes are designed today is by doing an exhaustively large number of experiments to find out how crystals grow and at what rate they grow under different conditions,” said UCSB chemical engineer Michael Doherty, an author of a paper that appears in the Proceedings of the National Academy of Sciences. Snowflakes, for instance, form differently as they fall, depending on variable conditions such as temperature and humidity, hence the widely held belief that no two are alike. After determining the optimal conditions for the growth of the crystal of choice, Doherty added equipment must be designed and calibrated to provide a consistent growing environment.

However, by pooling decades of expertise, Doherty, along with UCSB colleague Baron Peters and former graduate student Mark Joswiak (now at Dow Chemical) have developed a computational method to help predict growth rates for ionic crystals under different circumstances. Using a relatively simple crystal — sodium chloride (NaCl, more familiarly known as table salt) — in water, the researchers laid the groundwork for the analysis of more complex crystals.

Ionic crystals may appear to the naked eye — and even under some magnification — to consist of perfectly smooth and even faces. But look more closely and you’ll often find they actually contain surface features that influence their ability to grow, and the larger shapes that they take.

“There are dislocations and around the dislocations there are spirals, and around the spirals there are edges, and around the edges there are kinks,” Peters said, “and every level requires a theory to describe the number of those features and the rates at which they change.” At the smallest scale, ions in solution cannot readily attach to the growing crystal because water molecules that solvate (interact with) the ions are not readily dislodged, he said. With so many processes occurring at so many scales, it’s easy to see how difficult it can be to predict a crystal’s growth.

“The largest challenge was applying the various techniques and methods to a new problem — examining ion attachment and detachment at surface kink sites, where there is a lack of symmetry coupled with strong ion-water interactions,” Joswiak said. “However, as we encountered problems and found solutions, we gained additional insight on the processes, the role of water molecules and differences between sodium and chloride ions.”

Among their insights: Ion size matters. The researchers found that due to its size, the larger chloride ion (Cl-) prevents water from accessing kink sites during detachment, limiting the overall rate of sodium chloride dissolution in water.

“You have to find a special coordinate system that can reveal those special solvent rearrangements that create an opening for the ion to slip through the solvent cage and lock onto the kink site,” Peters said. “We demonstrated that at least for sodium chloride we can finally give a concrete answer.”

This proof-of-concept development is the result of the Doherty Group’s expertise with crystallization processes coupled with the Peters Group’s expertise in “rare events” — relatively infrequent and short-lived but highly significant phenomena (such as reactions) that fundamentally change the state of the system. Using a method called transition path sampling, the researchers were able to understand the events leading up to the transition state. The strategy and mechanistic insights from the work on sodium chloride provides a blueprint for predicting growth rates in materials synthesis, pharmaceuticals and biomineralization.

Boston Semi Equipment (BSE), a global semiconductor test handler manufacturer and provider of test automation technical services, today announced that it has started shipping units of its new strip load/unload module to a top 10 semiconductor manufacturer. The automation modules handle magazines containing strips holding semiconductor devices. The freestanding modules dock to strip-processing equipment via a SMEMA-compliant interface. Operators set up and control the modules using a color touch-screen monitor.

“BSE’s custom engineering group works with semiconductor companies to provide them the exact automation solutions they require,” said Kevin Brennan, vice president of marketing for BSE. “Our multidisciplined team started with our customer’s specification for the strip automation module, and handled the project from concept through to manufacturing of final units. With our global service organization, we can support these modules anywhere in the world.”

BSE’s custom engineering group helps companies accelerate their internal product development activities. Working with BSE, companies can implement cost savings and productivity improvement solutions sooner, helping to grow their market share and improve profits.

 

Silicon chips from STMicroelectronics (NYSE: STM) have enabled new zForce AIR(TM) touch-sensing modules from Neonode (NASDAQ: NEON), the optical sensor technology company.

Neonode’s compact, low-power, and easy-to-use modules add touch interaction to any USB- or I2C-connected object and work with any type of display or surface, including steel, wood, plastic, glass, skin, or even nothing, able to detect touch interactions in mid-air. The innovative approach uses laser-generated infrared light to track touch or gesture control, combining millimeter precision with ultra-fast response. The non-visible-spectrum light doesn’t impact display quality, add glare, or shift colors.

The new Neonode family of touch-sensors uses a programmable mixed-signal custom System-on-Chip (SoC) and an STM32 Arm® Cortex® microcontroller from ST for scanning laser diodes and IR beams to determine the exact position and movements of fingers, hands, or other reflective objects in the light path. Multiple objects can be tracked simultaneously and interpreted as touches or gestures with extreme accuracy: the coordinates are relayed up to 500 times per second with virtually zero delay.

“ST’s leading-edge chip-design capabilities and manufacturing processes have enabled us to build an innovative, high-performance optical-sensor system that is highly complex yet cost-competitive,” said Andreas Bunge, CEO of Neonode. “The advanced mixed-signal SoC and STM32 microcontroller at the heart of our new zForce AIR modules deliver the right combination of touch-control precision in real-time, low power consumption, and configurability.”

“This innovative sensing technology can make any object, surface, or space touch- interactive, bringing complete freedom of design,” said Iain Currie, Vice President North Europe Sales, STMicroelectronics. “Neonode’s decision to use ST technologies confirms our enabling role in the development of advanced applications that break new ground in man-machine interaction.”

Now available for immediate shipment worldwide through Digi-Key Electronics, the zForce AIR(TM) Touch Sensor modules will be displayed on ST’s stand at Embedded World 2018 (February 27 – March 1, Nuremberg).

Alpha and Omega Semiconductor Limited (AOS) (Nasdaq:AOSL), a designer, developer and global supplier of a broad range of power semiconductors and power ICs, today introduced AONE36132, a 25V N-Channel MOSFET in a dual DFN 3.3×3.3 package which is ideal for synchronous buck converters. The AONE36132 is an extension to the XSPairFET™ lineup.  Designed with the latest bottom source packaging technology, the AONE36132 has lower switch node ringing due to lower parasitic inductance. This new XSPairFET™ offers a higher power density compared to existing solutions and is ideally suited for computing, server and telecommunication markets.

AONE36132 has an integrated high-side and low-side MOSFETs (7mOhms and 2mOhms maximum on-resistance, respectively) within a DFN 3.3×3.3 XSPairFET™ package.  The low-side MOSFET source is connected directly to the exposed pad on PCB to enhance thermal dissipation.  Using an existing notebook design under typical conditions, 19V input Voltage, with 1.05V output Voltage, and a 21A output load condition, the AONE36132 had more than a two percent efficiency improvement when compared to a single DFN 5×6 high side and single DFN 5×6 low side configuration.

“The AONE36132 is the latest addition to the XSPairFET™ family which incorporates innovative technology to increase power density and improve efficiency for today’s demanding applications,” said Peter H. Wilson, Marketing Director of MOSFET product line at AOS.

Technical Highlights

The new product family offers various RDS(ON) levels in combination with multiple package options.

Part
Number		 Package VIN
(V)		 VGS
(±V)		 RDS(ON) (mΩ max)
at VGS =		 VGS (±V)
(max V)		 Ciss
(pF)		 Coss
(pF)		 Crss
(pF)		 Qg
(nC)		 Qgd
(nC)
10V 4.5V
AONE36132 DFN 3.3×3.3 High Side (Q1) 25 12 4.6 6 1.8 880 250 55 6.5 2.5
Low Side (Q2) 25 12 1.8 1.7 1.9 3125 860 200 25 6

Pricing and Availability

The AONE36132 is immediately available in production quantities with a lead-time of 12-14 weeks. The unit price for 1,000 pieces is $0.91.

 

Leti, a research institute at CEA Tech, has invented a lens-free microscope technology that provides point-of-care diagnosis for spinal meningitis. Outlined in a paper presented at Photonics West, the new technology provides immediate results and eliminates errors in counting white blood cells (leukocytes) in cerebrospinal fluid, which is required to diagnose the infection.

Spinal meningitis is an acute inflammation of the membranes covering the brain and spinal cord, which can be fatal within 24 hours. Until now, early diagnosis of the infection required an operator using an optical microscope to manually count white blood cells in cerebrospinal fluid.

“Until now, this process has been operator dependent, which limits where it can be used and increases the likelihood of errors in counting blood cells,” said Sophie NhuAn Morel, a co-author of the paper. “In our study, manual counts produced different results among five doctors.”

The bulky equipment and intensive human involvement, which can take 5-20 minutes to make a proper cell counting, make the traditional procedure unsuited for point-of-care diagnosis. As a result, meningitis cannot be diagnosed in emergencies or operating rooms, or during routine medical care in developing countries.

Reported in a paper titled “Lens-free Microscopy of Cerebrospinal Fluid for the Laboratory Diagnosis of Meningitis”, Leti’s lens-free, operator-free technology requires fewer than 10 microliters of cerebrospinal fluid to differentiate between white blood cells (leukocytes) and red blood cells (erythrocytes) in a point-of-care environment, using very small equipment.

“Leti’s lens-free technology can count leukocytes and erythrocytes almost in real-time and can be used in many different environments outside the lab,” Morel said.

The lens-free microscope was tested on 200 patients at Marseille Timone Hospital in France to detect or confirm spinal meningitis. A blind lens-free microscopic analysis of 116 cerebrospinal fluid specimens, including six cases of microbiologicallyconfirmed infectious meningitis, yielded a 100 percent sensitivity and a 79 percent specificity. Adapted lens-free microscopy is thus emerging as an operator-independent technique for rapidly counting leukocytes and erythrocytes in cerebrospinal fluid. In particular, this technique is well suited to the rapid diagnosis of meningitis at point-of-care labs.

In the near future, the reconstruction of both the magnitude and phase images from the raw diffraction pattern will allow the classification and numeration of all the blood cells in less than two minutes.

Leti, a technology research institute at CEA Tech, is a global leader in miniaturization technologies enabling smart, energy-efficient and secure solutions for industry.