nanotechnology (49)

NEMS Photothermal Microscopy...

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Topics: Microscopy, Nanotechnology, NEMS, Physics, Research

Single-molecule microscopy has become an indispensable tool for biochemical analysis. The capability of characterizing distinct properties of individual molecules without averaging has provided us with a different perspective for the existing scientific issues and phenomena. Recently, super-resolution fluorescence microscopy techniques have overcome the optical diffraction limit by the localization of molecule positions. However, the labeling process can potentially modify the intermolecular dynamics. Based on the highly sensitive nanomechanical photothermal microscopy reported previously, we propose optimizations on this label-free microscopy technique toward localization microscopy. A localization precision of 3 Å is achieved with gold nanoparticles, and the detection of polarization-dependent absorption is demonstrated, which opens the door for further improvement with polarization modulation imaging.

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FIG. 2. (a) Schematic of the measurement setup. BE: beam expander. M: mirror. WP: waveplate. LP: linear polarizer. BS: beam splitter. PD: photodetector/power meter. DM: dichroic mirror. ID: iris diaphragm. CCD: charge-coupled device camera. APD: avalanche photodiode detector. (b) The transduction scheme of the trampoline resonator. (c) SEM image of the trampoline resonator.

J. Appl. Phys. 128, 134501 (2020); https://doi.org/10.1063/5.0014905

Nanoelectromechanical photothermal polarization microscopy with 3 Å localization precision, Miao-Hsuan Chien and Silvan Schmid, Journal of Applied Physics

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B-TENG...

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Gentle breeze: illustration of the B-TENG triboelectric nanogenerator, which harvests electricity that is generated by fluttering polymer strips. (Courtesy: Xin Chen/Xiaojing Mu/Ya Yang)

Topics: Applied Physics, Nanotechnology, Polymers, Research

A new low-cost nanogenerator that can efficiently harvest electrical energy from ambient wind has been created by Ya Yang at the Beijing Institute of Nanoenergy and Nanosystems of the Chinese Academy of Sciences and colleagues. The team reports that the device achieves high electrical conversion efficiencies for breezes of 4–8 m/s (14–28 km/h) and says that it could be used to generate electricity in everyday situations, where conventional wind turbines are not practical.

As the drive to develop renewable sources of energy intensifies, there is growing interest in harvesting ambient energy in everyday environments. From breezes along city streets to the airflows created as we walk, the mechanical energy contained in ambient wind is abundant. The challenge is to harvest this every in an efficient and practical way. This has proven difficult using existing technologies such as piezoelectric films, which operate at very low power outputs.

Yang’s team based their new design around two well-known phenomena in physics. The first is the Bernoulli effect, which causes the fluttering of two adjacent flags to couple. If separated by a very small gap, the flags will flutter in-phase, while at slightly larger separations, they flap out-of-phase, and symmetrically about a central plane. The second is the triboelectric effect – the familiar phenomenon behind the “static electricity” that is created when different objects are rubbed together and then separated – resulting in opposite electrical charges on the objects and a voltage between the two.

Fluttering polymer ribbons harvest electrical energy, Physics World

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Transparency...

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Credit: Johannes Zirkelbach/Max Planck Institute for the Science of Light

 

Topics: Applied Physics, Nanotechnology, Optics

 

At the focus of a laser, a 100-nm-wide gold nanoparticle can block more than half the light. If additional particles are added, the amount of blocked light increases exponentially, as modeled by the Beer-Lambert law. But theorists predict that in the right set of circumstances, the addition of a molecule would, counterintuitively, decrease the light blocked—that is, make the nanoparticle partially transparent.

 

Vahid Sandoghdar of the Max Planck Institute for the Science of Light and his colleagues have now shown that predicted partial transparency for a near-field coupled dye molecule (red in image) and a plasmonic nanoparticle (gold). The phenomenon is a result of the interference between the light scattered from the two.

 

To achieve the required coupling, the dye molecule must be in a particular orientation and less than a wavelength away from the gold nanoparticle. Controlling those parameters is tricky, so Sandoghdar and his colleagues left them to chance. The researchers started with an array of nanoparticles and then coated it with a molten crystal doped with dibenzoterrylene (DBT) dye molecules. After the colorless crystal solidified, the result was a stochastic distribution of DBT molecules.

 

Their strong, distinctive fluorescence made the dye molecules easy to find optically. But the team members needed to verify that the molecule was near-field coupled to a nanoparticle. They identified a particle with two nearby DBT molecules and shined [a] tunable titanium: sapphire laser on it. The nanoparticle acts as an antenna, which enhances the molecules’ fluorescence. Relative to the other, one DBT molecule had telltale signatures of near-field interactions: enhanced and spectrally broadened fluorescence and a shorter excited-state lifetime—1.4 ns compared with the usual 8.1 ns.

 

Nanoparticle turns partially transparent, Heather Hill, Physics Today

 

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Graphene Currents...

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A picture of an electrical current in graphene (marked by the red outline) showing a fluid-like flow imaged using a diamond-based quantum sensor. The grey portion is where the metal electrical contacts prevented collection of data. Courtesy: Walsworth and Yacoby research groups, Harvard and University of Maryland

Topics: Materials Science, Nanotechnology, Quantum Mechanics, Semiconductor Technology

A team led by researchers from Harvard University and the University of Maryland in the US has used defects in diamond to map the magnetic field generated by electrical currents in graphene. Their experiments reveal that currents in this atomically-thin form of carbon flow like a viscous fluid – a result that could provide fresh insights into the collective behavior of electrons in strongly-interacting quantum systems.</em>

Graphene has many exceptional electrical properties. Among them is the fact that, at the point where its conduction and valence bands just touch each other (the Dirac point), it can support currents composed of electrons and an equal number of positively-charged holes, rather than electrons alone. In the present work, Ronald WalsworthAmir Yacoby and colleagues set out to establish whether these electron-hole plasmas (or Dirac fluids, as they are also known) flow smoothly, like electrons traveling through a metallic wire, or unevenly like water running through a pipe.

Diamond defects reveal viscous currents in graphene, Isabelle Dumé, Physics World

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Bright, Tiny, Powerful...

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The fin LED pixel design includes the glowing zinc oxide fin (purple), isolating dielectric material (green), and metal contact (yellow atop green). The microscopic fins, which the research team arranged into comb-like arrays, show an increase in brightness of 100 to 1,000 times over conventional submicron-sized LED designs.

Credit: B. Nikoobakht, N. Hanacek/NIST

Topics: Light-Emitting Diode, Nanotechnology, Solid-State Physics

A new design for light-emitting diodes (LEDs) developed by a team including scientists at the National Institute of Standards and Technology (NIST) may hold the key to overcoming a long-standing limitation in the light sources’ efficiency. The concept, demonstrated with microscopic LEDs in the lab, achieves a dramatic increase in brightness as well as the ability to create laser light — all characteristics that could make it valuable in a range of large-scale and miniaturized applications.

The team, which also includes scientists from the University of Maryland, Rensselaer Polytechnic Institute, and the IBM Thomas J. Watson Research Center, detailed its work in a paper published today in the peer-reviewed journal Science Advances. Their device shows an increase in brightness of 100 to 1,000 times over conventional tiny, submicron-sized LED designs.

A Light Bright and Tiny: NIST Scientists Build a Better Nanoscale LED

B. Nikoobakht, R.P. Hansen, Y. Zong, A. Agrawal, M. Shur and J. Tersoff. High-brightness lasing at submicrometer enabled by droop-free fin light-emitting diodes (LEDs). Science Advances. August 14, 2020. DOI: 10.1126/sciadv.aba4346

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Blind Mice Seeing...

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Topics: Bioengineering, Optical Physics, Nanorods, Nanotechnology

Even in the dark, rattlesnakes and their fellow pit vipers can strike accurately at small warm-blooded prey from a meter away. Those snakes, and a few others, can see in the IR—but not with their eyes. Rather, they have a pair of specialized sensory organs, called pit organs, located between their eyes and their nostrils and lined with nerve cells rich in temperature-sensitive proteins that cause the neurons to fire when heated.1 The pits work like pinhole cameras to focus incoming thermal radiation onto their heat-sensitive back walls; the thermal images are then superimposed with visual images in the snake’s brain.

Heat-responsive neurons are not unique to snakes. We have them over every inch of our skin, to feel objects warm to the touch, and on our tongues, to taste spicy food. But the snakes’ ability to resolve the source of radiated heat at a distance is unusual.

Inspired by the snakes, Dasha Nelidova and her colleagues at the Institute of Molecular and Clinical Ophthalmology in Basel, Switzerland, are developing a new treatment for forms of blindness caused by the degeneration of retinal photoreceptors.2 Using gene therapy, they endow remaining retinal cells with thermoresponsive proteins, thereby compensating for their lost light sensitivity with heat sensitivity. The proteins by themselves aren’t sensitive enough to rival normal vision, so the researchers tether them to gold nanorods, as shown in figure 1. The 80-nm-long nanorods strongly absorb near-IR light at 915 nm and convey the concentrated heat to the attached proteins.

Near-IR nanosensors help blind mice see, Johanna L. Miller, Physics Today

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Armored Surfaces...

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A schematic representation of how the surface looks, and how the structure repels water. Courtesy: Aalto University

 

Topics: Materials Science, Nanotechnology, Surface Engineering

A micron-scale “armor” that protects highly water-repellent nanostructures from damage has been developed by researchers in China and Finland. The new extra-durable coating could make it possible to employ these “superhydrophobic” surfaces on devices such as solar panels and vehicle windscreens that experience tough environmental conditions.

As their name suggests, superhydrophobic materials repel water extremely well. They owe this impressive ability to a thin layer of air that develops around nanometre-scale structures on their surface. By ensuring that droplets barely touch the solid part of the surface at all, the air layer effectively acts as a lubricant, allowing water droplets to roll off with near-zero friction.

These nanostructured surfaces are, however, mechanically fragile and can easily be wiped away. To address this drawback, a research team led by Xu Deng of the University of Electronic Science and Technology of China in Chengdu and Robin Ras of Finland’s Aalto University created a superhydrophobic surface containing structures at two different length scales: a nanoscale structure that is water repellent and a microscale one that provides durability.

The microstructure consists of an interconnected frame containing “pockets” of tiny inverted pyramids. Within these pyramids are the highly water-repellent and mechanically fragile nanostructures. The frame thus acts as a shield, preventing the nanostructure coating from being removed by abradants larger than the frame. “A finger, screwdriver or even sandpaper glides over these microstructures, leaving the nanostructures untouched, thereby preserving the surface’s attractive water-repellent feature,” Ras says.

Superhydrophobic surfaces toughen up, Isabelle Dumé, Physics World

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Comb on a Chip...

 

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Experimental setup to generate a set of stable frequencies in a cryogenically cooled laser microresonator frequency comb. The ring-shaped microresonator, small enough to fit on a microchip, operates at very low laser power and is made from the semiconductor aluminum gallium arsenide.

 

Topics: Applied Physics, Instrumentation, NIST, Nanotechnology, Semiconductor Technology

 

Just as a meter stick with hundreds of tick marks can be used to measure distances with great precision, a device known as a laser frequency comb, with its hundreds of evenly spaced, sharply defined frequencies, can be used to measure the colors of light waves with great precision.

Small enough to fit on a chip, miniature versions of these combs — so named because their set of uniformly spaced frequencies resembles the teeth of a comb — are making possible a new generation of atomic clocks, a great increase in the number of signals traveling through optical fibers, and the ability to discern tiny frequency shifts in starlight that hint at the presence of unseen planets. The newest version of these chip-based “microcombs,” created by researchers at the National Institute of Standards and Technology (NIST) and the University of California at Santa Barbara (UCSB), is poised to further advance time and frequency measurements by improving and extending the capabilities of these tiny devices.

Comb on a Chip: New Design for ‘Optical Ruler’ Could Revolutionize Clocks, Telescopes, Telecommunications, NIST

Paper: G. Moille, L. Chang, W. Xie, A. Rao, X. Lu, M. Davanco, J.E. Bowers and K. Srinivasan. Dissipative Kerr Solitons in a III-V Microresonator. Laser and Photonics Reviews. June 2020. DOI: 10.1002/lpor.202000022

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2D Boost for 5G...

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A diagram of the UT Austin team's switch showing two gold electrodes with a layer of hBN in between. (Courtesy: UT Austin)

 

Topics:  Boron Nitride, Internet of Things, Materials Science, Nanotechnology

Two-dimensional sheets of boron nitride can be used to create an analogue switch that gives communication devices more efficient access to radio, 5G and terahertz frequencies while increasing their battery life. The switch, which was developed by a team of researchers at the University of Texas at Austin in the US and the University of Lille in France, could be employed in a host of different applications, including smartphones, mobile systems and the “Internet of things”.

Analogue switches are routinely employed in communication systems to switch from one frequency band to another, route signals between transmitting and receiving antennas, and reconfigure wireless networks. Traditionally, these switches are based on solid-state diodes or transistors, but components of this type consume energy even in standby mode, reducing the battery life of the device. With 5G networking set to drive a tenfold increase in data throughput – enabling advances in self-driving cars, delivery drones, remote surgery and fast downloads of high-definition media in the process – addressing this energy drain is more urgent than ever.

5G switching gets a 2D boost, Isabelle Dumé, Physics World

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Photonic Nanojets...

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FIG. 1. (a) Long-legs cellar spider. (b) Reeling mechanism. (c) Manufacturing process of decorating spider silk. (d) Spider silk with dome lens placed on a dedicated holder. (e) Microphotograph of dome lens. (f) Laser scanning digital microscope system for measuring dome lens. (g) Schematic diagram of the dome lens for generating PNJ.

 

Topics: Biology, Materials Science, Nanotechnology

ABSTRACT

In this work, we thoroughly investigate the shape, size, and location of the photonic nanojets (PNJs) generated from the illuminated dome lens. The silk fiber is directly extracted from the cellar spider and used to form the dome lens by its liquid-collecting ability. The solidified dielectric dome lenses with different dimensions are obtained by using ultraviolet curing. Numerical and experimental results show that the long PNJs are strongly modulated by the dimension of the dome lens. The optimal PNJ beam shaping is achieved by using a mesoscale dielectric dome lens. The PNJ with a long focal length and a narrow waist could be used to scan over a target for large-area imaging. The silk fiber with a dome lens is especially useful for bio-photonic applications by combining its biocompatibility and flexibility.

Optimal photonic nanojet beam shaping by mesoscale dielectric dome lens

Journal of Applied Physics 127, 243110 (2020); https://doi.org/10.1063/5.0007611

C.B. Lin, Yi-Ting Lee, and Cheng-Yang Liu

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Greener Solar Cells...

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Scanning electron microscope image of electrodes infiltrated with quantum dots (left) and the corresponding distributions of copper, indium, zinc, and selenium across the film thickness. Courtesy: LANL
 
 

Topics: Green Tech, Nanotechnology, Quantum Mechanics, Solar Cells

Semiconducting nanocrystals called colloidal quantum dots (CQDs) are ideal for applications such as large-panel displays and photovoltaic cells thanks to their high efficiency and colour purity. Their main drawback is their toxicity, since they have traditionally been made from cadmium or other heavy metals, such as lead. Researchers at the Los Alamos National Laboratory in the US have now engineered cadmium-free QD solar cells that reach efficiencies on par with those of their environmentally-unfriendly counterparts. The key to the new devices’ high performance is their tolerance to defects, they say.

CQDs can be synthesized in solution, which means that films of these nanocrystals can be deposited quickly and easily on a range of flexible or rigid substrates – just like paint or ink. Such semiconducting nanocrystals are ideal for making highly-efficient inorganic solar cells that emit light via a process known as radiative recombination. Here, an electron in the valency energy band in the QD absorbs a photon and moves to the conduction band, leaving behind an electron vacancy, or hole. The excited electron and hole then recombine, releasing a photon.

The advantage of using CQDs as photovoltaic materials in solar cells is that they absorb light over a broad spectrum of solar radiation wavelengths. This is because the band gap of a CQD can be tuned over a large energy range by simply changing the size of the nanocrystals. Such a size-tuneable property has allowed the efficiencies of these QDs to rapidly approach those of traditional thin-film photovoltaics, such as PbS, CdTe and Pb-halide perovskite QDs.

Quantum dot solar cells get greener, Isabelle Dumé, Physics World

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"A Whole New Universe"...

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A Cryo-EM map of the protein apoferritin. Credit: Paul Emsley/MRC Laboratory of Molecular Biology

 

Topics: Biology, Cryogenic-Electron Microscopy, Materials Science, Nanotechnology

A game-changing technique for imaging molecules known as cryo-electron microscopy has produced its sharpest pictures yet — and, for the first time, discerned individual atoms in a protein.

By achieving atomic resolution using cryogenic-electron microscopy (cryo-EM), researchers will be able to understand, in unprecedented detail, the workings of proteins that cannot easily be examined by other imaging techniques, such as X-ray crystallography.

The breakthrough, reported by two laboratories late last month, cements cryo-EM’s position as the dominant tool for mapping the 3D shapes of proteins, say scientists. Ultimately, these structures will help researchers to understand how proteins work in health and disease, and lead to better drugs with fewer side effects.

“It’s really a milestone, that’s for sure. There’s really nothing to break anymore. This was the last resolution barrier,” says Holger Stark, a biochemist and electron microscopist at the Max Planck Institute for Biophysical Chemistry in Göttingen, Germany, who led one of the studies1. The other2 was led by Sjors Scheres and Radu Aricescu, structural biologists at the Medical Research Council Laboratory of Molecular Biology (MRC-LMB) in Cambridge, UK. Both were posted on the bioRxiv preprint server on 22 May.

“True ‘atomic resolution’ is a real milestone,” adds John Rubinstein, a structural biologist at the University of Toronto in Canada. Getting atomic-resolution structures of many proteins will still be a daunting task because of other challenges, such as a protein’s flexibility. "These preprints show where one can get to if those other limitations can be addressed,” he adds.

‘It opens up a whole new universe’: Revolutionary microscopy technique sees individual atoms for first time

Ewen Callaway, Nature

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Next big thing:
Haifei Zhan and colleagues reckon that carbon nanothreads have a future in energy storage.
(Courtesy: Queensland University of Technology)

 

Topics: Applied Physics, Battery, Materials Science, Nanotechnology

Computational and theoretical studies of diamond-like carbon nanothreads suggest that they could provide an alternative to batteries by storing energy in a strained mechanical system. The team behind the research says that nanothread devices could power electronics and help with the shift towards renewable sources of energy.

The traditional go-to device for energy storage is the electrochemical battery, which predates even the widespread use of electricity. Despite centuries of technological progress and near ubiquitous use, batteries remain prone to the same inefficiencies and hazards as any device based on chemical reactions – sluggish reactions in the cold, the danger of explosion in the heat and the risk of toxic chemical leakages.

Another way of storing energy is to strain a material that then releases energy as it returns to its unstrained state. The strain could be linear like stretching and then launching a rubber band from your finger; or twisted, like a wind-up clock or toy. Over a decade ago, theoretical work done by researchers at the Massachusetts Institute of Technology suggested that strained chords made from carbon nanotubes could achieve impressive energy-storage densities, on account of the material’s unique  mechanical properties.

Diamond nanothreads could beat batteries for energy storage, theoretical study suggests

Anna Demmings, Physics World
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Open University...


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Topics: Applied Physics, Education, Internet, Nanotechnology, STEM


Today poignantly, is the 50th anniversary of Earth Day. Some of us celebrate in willing self-isolation; others wish a repeat of the 1918 Influenza Pandemic by callously campaigning for others to die for an economy so wrought with inequality it cannot handle it's centennial equivalent.

A disclaimer note: Though these are unique times to say the least, this is not a support for fully online STEM education, though there can be some. Science for the most part is done in-person. I hope this is a bridge until we get to that again. It's hard to Zoom a breadboard circuit design or a laboratory set up.

Worldwide demand is growing for effective STEM (science, technology, engineering, and mathematics) education that can produce workers with technical skills. Online classes—affordable, flexible, and accessible—can help meet that demand. Toward that goal, some countries have developed national online higher-education platforms, such as XuetangX in China and Swayam in India. In 2015 eight top Russian universities collaborated to create the National Platform of Open Education, or OpenEdu. Professors from highly ranked departments produced courses for the platform that could then be used, for a fee, by resource-constrained universities. The courses comply with national standards and enable universities to serve more students by reducing the cost per pupil.

A new study from Igor Chirikov at the University of California, Berkeley, and his collaborators at Stanford and Cornell Universities and the National Research University Higher School of Economics in Moscow investigates the effectiveness of the OpenEdu program. The researchers looked at two metrics—effectiveness of instruction and cost savings—and found that the platform was successful on both fronts.

 

Online STEM courses can rival their in-person analogues
Christine Middleton, Physics Today

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So Much for Moore...

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Figure 1: Planar transistors vs finFETs vs nanosheet FET. Source: Samsung

 

Topics: Applied Physics, Electrical Engineering, Moore's Law, Nanotechnology, Semiconductor Technology


So much for the Moore's law limit. Although under current circumstances, the progression might be stalled by our current viral situation: the cost of chips will go higher, and consumers are currently making choices on food, jobs and toilet paper, not gadgets.

Select foundries are beginning to ramp up their new 5nm processes with 3nm in R&D. The big question is what comes after that.

Work is well underway for the 2nm node and beyond, but there are numerous challenges as well as some uncertainty on the horizon. There already are signs that the foundries have pushed out their 3nm production schedules by a few months due to various technical issues and the unforeseen pandemic outbreak, according to analysts. COVID-19 has slowed the momentum and impacted the sales in the IC industry.

This, in turn, is likely to push back the roadmaps beyond 3nm. Nevertheless, the current climate hasn’t stopped the semiconductor industry. Today, foundries and memory makers are running at relatively high fab utilization rates.

Behind the scenes, meanwhile, foundries and their customers continue to develop their 3nm and 2nm technologies, which are now slated for roughly 2022 and 2024, respectively. Work is also underway for 1nm and beyond, but that’s still far away.

Starting at 3nm, the industry hopes to make the transition from today’s finFET transistors to gate-all-around FETs. At 2nm and perhaps beyond, the industry is looking at current and new versions of gate-all-around transistors.

At these nodes, chipmakers will likely require new equipment, such as the next version of extreme ultraviolet (EUV) lithography. New deposition, etch and inspection/metrology technologies are also in the works.

Needless to say, the design and manufacturing costs are astronomical here. The design cost for a 3nm chip is $650 million, compared to $436.3 million for a 5nm device, and $222.3 million for 7nm, according to IBS. Beyond those nodes, it’s too early to say how much a chip will cost.

 

Making Chips At 3nm And Beyond
Mark Lapedus and Ed Sperling, Semiconductor Engineering

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Silicon Sees the Light...

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Silicon sees the light: Elham Fadaly (left) and Alain Dijkstra in their Eindhoven lab. (Courtesy: Sicco van Grieken/SURF)

 

Topics: Optics, Electrical Engineering, Nanotechnology, Research, Solar Power, Spectroscopy


A light-emitting silicon-based material with a direct bandgap has been created in the lab, fifty years after its electronic properties were first predicted. This feat was achieved by an international team led by Erik Bakkers at Eindhoven University of Technology in the Netherlands. They describe the new nanowire material as the “Holy Grail” of microelectronics. With further work, light-emitting silicon-based devices could be used to create low-cost components for optical communications, computing, solar energy and spectroscopy.

Silicon is the wonder material of electronics. It is cheap and plentiful and can be fabricated into ever smaller transistors that can be packed onto chips at increasing densities. But silicon has a fatal flaw when it comes to being used as a light source or solar cell. The semiconductor has an “indirect” electronic bandgap, which means that electronic transitions between the material’s valence and conduction bands involve vibrations in the crystal lattice. As a result, it is very unlikely that an excited electron in the conduction band of silicon will decay to the valence band by emitting light. Conversely, the absorption of light by silicon does not tend to excite valence electrons into the conduction band – a requirement of a solar cell.

 

Silicon-based light emitter is ‘Holy Grail’ of microelectronics, say researchers
Hamish Johnston, Physics World

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Moore's Reckoning...

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Wiki Chip: 14 nm lithography process

 

Topics: Electrical Engineering, Moore's Law, Nanotechnology, Semiconductor Technology


It was hard to tell at the time — with the distraction of the Y2K bug, the explosion of reality television, and the popularity of post-grunge music — that the turn of the millennium was also the beginning of the end of easy computing improvements. A golden age of computing, which powered intensive data and computational science for decades, would soon be slowly drawing to a close. Even with novel ways of assembling computing systems, and new algorithms that take advantage of the architecture, the performance gains as predicted by Moore’s law were bound to come to an end — but in a way few people expected.

Moore’s law is the observation that the number of transistors in dense integrated circuits doubles roughly every two years. Before the turn of the millennium, all a computational scientist needed to do to have more than twice as fast a computer was to wait two years. Calculations that would have been impractical became accessible to desktop users. It was a time of plenty, and many problems could be solved by brute-force computing, from the quantum interactions of particles to the formation of galaxies. Giant lattices could be modeled, and enormous numbers of particles tracked. Improved computers enabled the analysis of genomic variations in entire communities and facilitated the advent of machine-learning techniques in AI.

Fundamental physics limits will ultimately put an end to transistor shrinkage in Moore’s law, and we are close to getting there. Today, chip production creates structures in silicon that are 14 nanometers wide and decreasing, and seven-nanometer elements are coming to market. At these sizes, thousands of these elements would fit in the width of a human hair. Feature sizes of less than five nanometers will probably be impossible because of quantum tunneling, in which electrons undesirably leak out of such narrow gaps.

 

A Reckoning for Moore’s Law
Why upgrading your computer every two years no longer makes sense.
Ian Fisk, Simon's Foundation

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Interphase...

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Intro to Nano Energy: Lecture 5

 

Topics: Battery, Materials Science, Nanotechnology


What happens in a lithium-ion battery when it first starts running? A complex series of events, it turns out – from electrolytic ion reorganization to a riot of chemical reactions. To explore this early part of a battery’s life, researchers in the US have monitored a battery’s chemical evolution at the electrode surface. Their work could lead to improved battery design by targeting the early stages of device operation.

The solid-electrolyte interphase is the solid gunk that materializes around the anode. Borne from the decomposition of the electrolyte, it is crucial for preventing further electrolyte degradation by blocking electrons while allowing lithium ions to pass through to complete the electrical circuit.

The solid-electrolyte interphase does not appear immediately. When a lithium ion battery first charges up, the anode repels anions and attracts positive lithium ions, separating oppositely charged ions into two distinct layers. This electric double layer dictates the eventual composition and structure of the solid-electrolyte interphase.

 

Emergence of crucial interphase in lithium-ion batteries is observed by researchers
Shi En Kim, Physics World

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Dilemma...

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Green Book Blog: The Technology Dilemma, Zoë Dowling

 

Topics: Biology, Chemistry, COVID-19, Nanotechnology, Physics, Research, STEM


As the coronavirus outbreak roils university campuses across the world, early-career scientists are facing several dilemmas. Many are worrying about the survival of cell cultures, laboratory animals, and other projects critical to their career success. And some are reporting feeling unwelcome pressure to report to their laboratories—even if they don’t think it’s a good idea, given that any gathering can increase the risk of spreading the virus.

It’s unclear exactly how common these concerns are, but social media posts reveal numerous graduate students expressing stress and frustration at requests to come to work. “Just emailed adviser to say I am not comfortable breaking self isolation to come to lab this week. They emailed … saying I have to come in. What do I do?” tweeted an anonymous Ph.D. student on 16 March who doesn’t have essential lab work scheduled. “My health & safety should NOT be subject to the whims of 1 person. It should NOT be this scary/hard to stand up for myself.”

Many universities, including Harvard, have moved to shut down all lab activities except for those that are deemed “essential,” such as maintaining costly cell lines, laboratory equipment, live animals, and in some cases, research relating to COVID-19. But others have yet to ban nonessential research entirely.

 

Amid coronavirus shutdowns, some grad students feel pressure to report to their labs
Michael Price, Science Magazine, AAAS

I feel their pain.


The Scientific Method is very simple in concept:

Problem research - This involves gathering data in the form of previous written papers, published and peer-reviewed; writing notes (for yourself), summaries and reviews.

Hypothesis - This is your question asked from all the research, discussion with your adviser, especially if it's a valid question to ask or research to pursue.

Test the hypothesis - Design of experiment (s) to verify the hypothesis.

Data analysis - Usually with a software package, and a lot of statistical analysis.

Conclusion - Does it support the hypothesis?

- If so, retest several times, to plot an R squared fit of the data, so predictions can be made.

- If not, form another hypothesis and start over.

Often, conclusions are written up for peer review to be considered for journal publication. No one ever gets in on first submission - get used to rejection. Conclusions will be challenged by subject matter experts that may suggest other factors to consider, or another way to phrase something. Eventually, you get published. You can then submit an abstract to present a poster and a talk at a national conference.

Meeting Cancellation

It is with deep regret that we are informing you of the cancellation of the 2020 APS March Meeting in Denver, Colorado. APS leadership has been monitoring the spread of the coronavirus disease (COVID-19) constantly. The decision to cancel was based on the latest scientific data being reported, and the fact that a large number of attendees at this meeting are coming from outside the US, including countries where the CDC upgraded its warning to level 3 as recently as Saturday, February 29.

 

APS Physics: March.APS/about/coronavirus/


Update on Coronavirus

The health and safety of MRS members, attendees, staff, and community are our top priority. For this reason, we are canceling the 2020 MRS Spring Meeting scheduled for April 13-17, 2020, in Phoenix.

With our volunteers, we are exploring options for rescheduling programming to an upcoming event. We will share more information as soon as it becomes available.

 

MRS: Materials Research Society/2020-Spring Meeting


Social distancing and "shelter-in-place" slows the scientific enterprise. Science is in-person and worked out with other humans in labs and libraries. However, I am in support of this action and reducing the impact on the healthcare industry that on normal days are dealing with broken bones, gunshot wounds; cancer and childbirth surgeries with anxious, expectant mothers.

The dilemma is the forces that would reject the science behind this pandemic (and most science in any endeavor), would have us all "go back to work" after two weeks. The curve we're trying to flatten could sharply spike. The infection rates would increase and otherwise healthy people would be stricken. Immunodeficient groups would start getting sick again ...dying again. Our infrastructure is not designed for that many sick or dead people. Science continues with our survival and societal stability.

The persons with the solutions might be chomping-at-the-bit at home for now. Survival insures science will continue ...someday.
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A graduate student gains hands-on experience with state-of-the-art nanotechnology equipment in the Center for Nanotechnology Education and Utilization Teaching Cleanroom.

CREDIT
Penn State

 

Topics: African Americans, Diversity, Diversity in Science, Existentialism, Nanotechnology, STEAM

Related: Be Thankful for What You Got, William DeVaughn, Genius Lyrics


Note: When this post appears, I will be in a midterm in Solid State Devices. I purposely did not post yesterday to let the tribute to Ms. Katherine Johnson Tuesday be an appropriate and respectful dénouement. After Friday seminar, I will take a needed spring break.

Nanotechnology is STEM at the 10-9 meter scale: a nanometer. To advance any understanding at that level, there has to be a respect for objective truth:

A proposition is considered to have objective truth when its truth conditions are met without bias caused by a sentient subject. Scientific objectivity refers to the ability to judge without partiality or external influence, sometimes used synonymous with neutrality. Wikipedia

After Watergate, a political party created its own echo chamber in print, radio, television and the Internet that now confuses objective versus subjective truth, i.e. that which matters in ones own opinion is therefore defended as "fact." We're daily inundated with the solipsistic subjective truth of a pathological liar, which that in and of itself is an area of mental illness as democracy is not a matter of "opinion," but a debate over a shared view of facts and what if anything will be done to ameliorate any problem put forwards. Ostrich politics doesn't even work for ostriches: like most foul, their not burying their heads in sand, they eat it and gravel to aid with their digestion.

Raking and mopping will not address climate change; neither will denying the spreading of the coronavirus in the west. It doesn't help that funding for the CDC and HHS were cut, and a lot of government agencies designed to fight pandemics either shuttered, unfunded or both. Forgive me if I'm dubious that the party whose senator brings a snowball to the well of the senate to disprove climate change won't eventually cut what we could innovate in nanotechnology, particularly expanding it to underrepresented groups to participate. They wouldn't see the value it gives to all Americans because they are just that myopic.

November 3, 2020 might as well be Judgment Day, when we either right this ship of state from the impact of ignoramuses and "alternative facts," or this dark momentum will edge us over the precipice into dystopia. Once America falls - and I'm sure her enemies know this - all other democracies around the world and civilization, is in peril.

Like the right wing truckers with smokestacks to "own the libs": we all have to live on the same planet: cooperation, or extinction.

 

*****


New Louis Stokes Regional Center of Excellence created with National Science Foundation funding

Traditionally, minority students have been underrepresented in science, technology, engineering and mathematics (STEM) programs -- and in the STEM marketplace. And as the U.S. innovation economy continues to grow, there comes an increasing requirement for skilled STEM workers to maintain the nation's status as a global leader. However, a significant challenge for workforce diversity exists because of limited access to underrepresented populations to quality STEM education and opportunities for STEM employment.

To try and overcome this challenge and ensure national competitiveness and sustained STEM global leadership, the Penn State Center for Nanotechnology Education and Utilization (CNEU), along with Norfolk State University (NSU) and Tidewater Community College (TCC), will form the Southeastern Coalition for Engagement and Exchange in Nanotechnology Education (SCENE) Louis Stokes Regional Center of Excellence in Broadening Participation. A total of $1.2 million in funding for this center was recently awarded by the National Science Foundation.

SCENE will focus on increasing recruitment and retention of underrepresented minority (URM) undergraduate and graduate students at Historically Black Colleges and Universities (HBCU) and at community colleges with minority and underrepresented student enrollments. Recruitment efforts will be aimed at students studying STEM through nanoscience and nanotechnology education and engagement.
 

 

Nanotechnology center to help broaden participation of minorities in STEM fields
6 December 2018, Penn State


SO let us summon a new spirit of patriotism; of service and responsibility where each of us resolves to pitch in and work harder and look after not only ourselves, but each other. Let us remember that if this financial crisis taught us anything, it’s that we cannot have a thriving Wall Street while Main Street suffers – in this country, we rise or fall as one nation; as one people.

We Rise and Fall as ONE Nation, November 5, 2008, President-elect Barack Obama, New York Post

"We must learn to live together as brothers or perish together as fools." Dr. Martin Luther King, Jr.
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