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reconfigurable 3-in-1 semiconductor device

SUNY Polytechnic Creates 3-in-1 Device That Can Be A Diode, A MOSFET And A BJT

In a recently published study, a team of researchers at SUNY Polytechnic Institute in Albany, New York, has suggested that combining multiple functions in a single semiconductor device can significantly improve device’s functionality and efficiency.

Nowadays, the semiconductor industry is striving to scale down the device dimensions in order to fit more transistors onto a computer chip and thus improve the speed and efficiency of the devices. According to Moore’s law, the number of transistors on a computer chip cannot exponentially increase forever. For this reason, scientists are trying to find other ways to improve semiconductor technologies.

To demonstrate the new technology which can be an alternative to Moore’s law, the researchers of SUNY Polytechnic designed and fabricated a reconfigurable device that can be a p-n diode (which functions as a rectifier), a MOSFET (for switching), and a bipolar junction transistor (or BJT, for current amplification). Though these three devices can be fabricated individually in modern semiconductor fabrication plants, it often becomes very complex if they are to be combined.

reconfigurable 3-in-1 semiconductor device
the reconfigurable 3-in-1 semiconductor device

Ji Ung Lee at the SUNY Polytechnic Institute said,

We are able to demonstrate the three most important semiconductor devices (p-n diode, MOSFET, and BJT) using a single reconfigurable device. We can form a single device that can perform the functions of all three devices.

The multitasking device is made of 2-D tungsten diselenide (WSe2), a new transition metal dichalcogenide semiconductor. This class of materials is special as the bandgap is tunable by varying the thickness of the material. It is a direct bandgap while in single layer form.

Another challenge was to find a suitable doping technique as WSe2 lacks one being a new material. So, to integrate multiple functions into a single device, the researchers developed a completely new doping method. By doping, the researchers could obtain properties such as ambipolar conduction, which is the ability to conduct both electrons and holes under different conditions. Lee said,

Instead of using traditional semiconductor fabrication techniques that can only form fixed devices, we use gates to dope.

These gates can control which carriers (electrons or holes) should flow through the semiconductor. In this way, the ambipolar conduction is achieved. The ability to dynamically change the carriers allows the reconfigurable device to perform multiple functions. Another advantage of using gates in doping is, it saves overall area and enable more efficient computing. As consequence, the reconfigurable device can potentially implement certain logic functions more compactly and efficiently.

In future, researchers plan to investigate the applications of this new technology and want to enhance its efficiency further. As Lee said,

We hope to build complex computer circuits with fewer device elements than those using the current semiconductor fabrication process. This will demonstrate the scalability of our device for the post-CMOS era.

Prosthetics Feeling Is Now Possible With This Implantable Chip By Imec

Imec, the world-leading research and innovation hub in nano-electronics and digital technology, announced last month its prototype implantable chip that aims to give patients more intuitive control over their arm prosthetics. The thin-silicon chip is said to be world’s first for electrode density. Creating a closed-loop system for future-generation haptic prosthetics technology is the aim of researchers.

What is special about this chip?

The already available prosthestics are efficient and have their own key features; like giving amputees the ability to move their artificial arm and hand to grasp and manipulate objects. This is done by reading out signals from the person’s muscles or peripheral nerves to control electromotors in the prosthesis. Good news is that revolutionary features are coming! The future prosthetics will provide amputees with rich sensory content. This can be done by delivering precise electrical patterns to the person’s peripheral nerves using implanted electrode interfaces.

The goal behind working on this new technique is to create a new peripheral nerve interfaces with greater channel count, electrode density, and information stability according to Rizwan Bashirullah, director of the University of Florida’s IMPRESS program (Implantable Multimodal Peripheral Recording and Stimulation System)

Fabricated amazingly in a small scale!

A prototype of ultrathin (35µm) chip with a biocompatible, hermetic and flexible packaging is now available. On its surface are 64 electrodes, with a possible extension to 128. This large amount of electrodes is used for fine-grained stimulation and recording. As the short video shows, the researchers will insert the package and attach it to a nerve bundle using an attached needle which will give better results compared to other solutions usually wrapped around nerve bundles.

“Our expertise in silicon neuro-interfaces made imec a natural fit for this project, where we have reached an important milestone for future-generation haptic prosthetics,” commented Dries Braeken, R&D manager and project manager of IMPRESS at imec. “These interfaces allow a much higher density of electrodes and greater flexibility in recording and stimulating than any other technology. With the completion of this prototype and the first phase of the project, we look forward to the next phase where we will make the prototype ready for long-term implanted testing.”

The Defense Advanced Research Projects Agency’s (DARPA) Biological Technologies Office sponserd this work of University of Florida researchers under the auspices of Dr. Doug Weber through the Space and Naval Warfare Systems Center. For more details about this topic check this article.

New Batteries with 3 & 15 Times Energy Density

With the rapid growth of battery-based devices and tools, efficient energy storage systems are becoming more and more important. Of course there are many researches running around the world working on novel battery technologies. Two new cell technologies are working to deliver energy density of 3 and 15 times of conventional lithium cells.

The first is a group of scientists from Rice University, they solved the dendrite problem of commercial lithium-ion batteries providing a three times capacity rechargeable lithium metal battery. Dendrites are whiskers of lithium that grow inside batteries, and they can cause fires like those in the Samsung Galaxy Note 7. They are considered a major issue for next-generation lithium batteries.

Lithium metal coats the hybrid graphene and carbon nanotube anode in a battery created at Rice University. The lithium metal coats the three-dimensional structure of the anode and avoids forming dendrites. Courtesy of the Tour Group.
Lithium metal coats the hybrid graphene and carbon nanotube anode in a battery created at Rice University. The lithium metal coats the three-dimensional structure of the anode and avoids forming dendrites. Courtesy of the Tour Group.

The main idea of the research is to coat high conductive hybrid graphene and carbon nanotubes with metallic lithium. These low density and high surface area nanotubes have space for lithium particles to slip in and out as the battery charges and discharges.

“Lithium-ion batteries have changed the world, no doubt, but they’re about as good as they’re going to get. Your cellphone’s battery won’t last any longer until new technology comes along.”  – James Tour, leader of the research team

A prototype of a battery with 3.351 Ah/g capacity, retains 80% of the original capacity after 500 charge cycles.

In Japan, and especially at the NIMS (National Institute for Materials Science), another research is working to create a Lithium-air battery that has the highest theoretical energy density because it uses oxygen in air. Its capacity reaches 15 times of the conventional Lithium batteries.

The electrode material has an enormous surface area thanks to ​​carbon nanotubes. Researchers achieved 30 mAh/cm² capacity in the lab, which will be amazing if realized in a commercial product. Work is ongoing to produce real practical samples with high energy density and a system to filter impurities from the air.

Source: Elektor

Virtual telescope makes first image of a black hole

by Eric Bogers @ elektormagazine.com discuss about a new project that aims to create the first image of a black hole. He writes:

A powerful network of radio telescopes, spread around our planet, attempts for the first time to create an image of a black hole. Black holes are intangible gravitational ‘vanishing holes’, the existence if which was already predicted in 1915 by Albert Einstein. The South Pole Telescope of the University of Chicago is part of this Event Horizon Telescope, in which eight observatories, spread across six widely dispersed locations, together form a single virtual telescope, which is so powerful (has sufficiently great resolving power) that it could detect a penny on the surface of the moon.

Virtual telescope makes first image of a black hole – [Link]

Artificial Magnetic Fields For Photons

Photons became a hot research topic due to their important role in holding data across long distances. Starting from the fact that photons are insensitive to magnetic fields which concludes to their disability to process data, a group of researchers from the ETH (Eidgenössische Technische Hochschule) in Zürich are trying to make photons controlled with electric fields by giving them some electrical charge.

Visualisations: Colourbox / Montage Josef Kuster)

Photons or Polaritons?

They are using polaritons in their approach to build this artificial magnetic field. Polaritons are hybrid particles consist of coupling a photon with an electric dipole. When photons enter a material, the electrons allow themselves to be moved by the light waves or ‘polarize’, they form polaritons – coupled light and polarization waves, or excitons. Meaning that they could convert photons  into polaritons. Packing excitons with them as a luggage, we can now steer polaritons  indirectly by the magnetic fields.

“The combined effect of magnetic and electric fields on polaritons then leads to a gauge potential”, says Hyang-Tag Lim, a post-doctoral researcher in Imamoğlu’s laboratory.

Researches are comparing the gauge potential to a tiltable lifting platform. For example, when trying to lift a vehicle, the potential energy will change, but the vehicle won’t move. However, once we tilt the platform, a difference in height along the platform happens and the vehicle will move. Thus, a gauge potential will result in an effective magnetic field only if it varies in space.

The researchers are now looking for ways to strengthen gauge potentials. Researchers had published this researchers in the scientific journal Nature Communications, you can have a look at the research here.

Source: ETH Zurich

The First 3D Quantum Liquid Crystals

Strong electron interactions can drive metallic systems toward a variety of well-known symmetry-broken phases, but the instabilities of correlated metals with strong spin-orbit coupling have only recently begun to be explored.

A team of physicists at the Institute for Quantum Information and Matter at Caltech, had discovered an new state of matter that may have applications in ultra-fast quantum computers of the future. It is the first three-dimensional quantum liquid crystal.

“We have detected the existence of a fundamentally new state of matter that can be regarded as a quantum analog of a liquid crystal, There are numerous classes of such quantum liquid crystals that can, in principle, exist; therefore, our finding is likely the tip of an iceberg.” says Caltech assistant professor of physics David Hsieh, principal investigator on a new study describing the findings in the April 21 issue of Science.

Liquid crystals are materials that are between liquid and solid, they are consisted of molecules that flow around freely as if they were a liquid but are all oriented in the same direction, as in solid. An important feature of the liquid crystals that in addition to availability in the nature, they can be made artificially like those used in items that have display screens.

In 1999, the first quantum liquid crystal was discovered by Caltech’s Jim Eisenstein, the Frank J. Roshek Professor of Physics and Applied Physics. It was a two-dimensional which means that it was limited with a single plane inside the host material. In a quantum liquid crystal, electrons behave like the molecules in classical liquid crystals. They move around freely in a preferred direction of flow.

These images show light patterns generated by a rhenium-based crystal using a laser method called optical second-harmonic rotational anisotropy. At left, the pattern comes from the atomic lattice of the crystal. At right, the crystal has become a 3-D quantum liquid crystal, showing a drastic departure from the pattern due to the atomic lattice alone.

The behavior of the electrons in the newly discovered 3D-variant are possibly even stranger. The electrons do not only distinguish between x-, y- and z-axis, but they also have different magnetic characteristics depending along which axis they move back and forth.

According to the researchers, the 3D quantum liquid crystals could play a role in a field called spintronics, where the spin direction of electrons can be utilized to create more efficient computer chips. It may also help with some of the challenges of building a quantum computer, which seeks to take advantage of the quantum nature of particles to make even faster calculations.

“Rather than rely on serendipity to find topological superconductors, we may now have a route to rationally creating them using 3-D quantum liquid crystals” says Harter. “That is next on our agenda.”

You can read more about this research through the published paper and by reading Caltech’s post.

Self-learning neuromorphic chip composes music

Peter Clarke @  eedesignnewseurope.com reporting:

Research institute IMEC has created a neuromorphic chip based on metal-oxide ReRAM technology that has the ability to self-learn. That self-learning has been applied to music making.

Self-learning neuromorphic chip composes music – [Link]

3D NAND flash 72 layers

SK Hynix Introduces Industry’s Highest 72-Layer 3D NAND Flash

SK Hynix Incorporated introduced the world’s first 72-Layer 256Gb (Gigabit) 3D (Three-Dimensional) NAND Flash based on its TLC (Triple-Level Cell) arrays and own technologies. This company also launched 6-Layer 128Gb 3D NAND chips in April 2016 and has been mass producing 48-Layer 256Gb 3D NAND chips since November 2016. Within 5 months the researchers in SK Hynix developed the new technology of producing 72-layer 3D NAND flash.

3D NAND flash 72 layers
72 layers 3D NAND flash

The technological achievement of this 72-Layer 3D NAND is compared to the difficulty of building approximately 4 billion 72-storied skyscrapers on a single dime. Well, now the question maybe, “Is the difficulty and complexity of this new technology giving any remarkable outcome?”. The answer is a big YES. The 72-layer NAND is said to stack 1.5 times more cells than the 48-layer, achieving 30% more efficiency in productivity and 20% higher read/write performance than a 48-layer 3D NAND chip, the predecessor of this 72-layer .D 256Gb NAND flash.

With this new chips having 30% more efficiency in productivity and 20% higher performance, SK Hynix has been currently developing NAND Flash solutions such as SSD (Solid State Drive) and storage for mobile devices such as smartphones. Having high reliability and low power consumption this 3D NAND flash should be an ideal solution for storage problems of mobile devices.

SK Hynix plans to expand the usage of the product to SSDs and mobile gadgets to further improve its business structure weighted towards DRAM. The vice president Jong Ho Kim said in the press release,

With the introduction of this industry’s highest productivity 3D NAND, SK Hynix will mass produce the 256Gb 3D NAND in the second half of this year to provide this to worldwide business clients for optimum use in storage solutions

According to a market research, 3D NAND flash demand is rapidly increasing across AI(Artificial Intelligence), big data, and cloud storage. The research by Gartner says that NAND Flash market revenue is expected to total USD 46.5 billion in this year and it will grow up to an amount of USD 56.5 billion in 2021.

Affordable DNA Detection Using A Smartphone

Researchers at UCLA have developed an improved method to detect the presence of DNA biomarkers of disease that is compatible with use outside of a hospital or lab setting. The new technique leverages the sensors and optics of cellphones to read light produced by a new detector dye mixture that reports the presence of DNA molecules with a signal that is more than 10-times brighter.

Nucleic acids, such as DNA or RNA, are used in tests for infectious diseases, genetic disorders, cancer mutations that can be targeted by specific drugs, and fetal abnormality tests. The samples used in standard diagnostic tests typically contain only tiny amounts of a disease’s related nucleic acids. To assist optical detection, clinicians amplify the number of nucleic acids making them easier to find with the fluorescent dyes.

Both the amplification and the optical detection steps have in the past required costly and bulky equipment, largely limiting their use to laboratories.

In a study published online in the journal ACS Nano, researchers from three UCLA entities — the Henry Samueli School of Engineering and Applied Science, the California NanoSystems Institute, and the David Geffen School of Medicine — showed how to take detection out of the lab and for a fraction of the cost.

The collaborative team of researchers included lead author Janay Kong, a UCLA Ph.D. student in bioengineering; Qingshan Wei, a post-doctoral researcher in electrical engineering; Aydogan Ozcan, Chancellor’s Professor of Electrical Engineering and Bioengineering; Dino Di Carlo, professor of bioengineering and mechanical and aerospace engineering; and Omai Garner, assistant professor of pathology and medicine at the David Geffen School of Medicine at UCLA.

The UCLA researchers focused on the challenges with low-cost optical detection. Small changes in light emitted from molecules that associate with DNA, called intercalator dyes, are used to identify DNA amplification, but these dyes are unstable and their changes are too dim for standard cellphone camera sensors.

But the team discovered an additive that stabilized the intercalator dyes and generated a large increase in fluorescent signal above the background light level, enabling the test to be integrated with inexpensive cellphone based detection methods. The combined novel dye/cellphone reader system achieved comparable results to equipment costing tens of thousands of dollars more.

To adapt a cellphone to detect the light produced from dyes associated with amplified DNA while those samples are in standard laboratory containers, such as well plates, the team developed a cost-effective, field-portable fiber optic bundle. The fibers in the bundle routed the signal from each well in the plate to a unique location of the camera sensor area. This handheld reader is able to provide comparable results to standard benchtop readers, but at a fraction of the cost, which the authors suggest is a promising sign that the reader could be applied to other fluorescence-based diagnostic tests.

“Currently nucleic acid amplification tests have issues generating a stable and high signal, which often necessitates the use of calibration dyes and samples which can be limiting for point-of-care use,” Di Carlo said. “The unique dye combination overcomes these issues and is able to generate a thermally stable signal, with a much higher signal to noise ratio. The DNA amplification curves we see look beautiful — without any of the normalization and calibration, which is usually performed, to get to the point that we start at.”

Additionally, the authors emphasized that the dye combinations discovered should be able to be used universally to detect any nucleic acid amplification, allowing for their use in a multitude of other amplification approaches and tests.

The team demonstrated the approach using a process called loop-mediated isothermal amplification, or LAMP, with DNA from lambda phage as the target molecule, as a proof of concept, and now plan to adapt the assay to complex clinical samples and nucleic acids associated with pathogens such as influenza.

The newest demonstration is part of a suite of technologies aimed at democratizing disease diagnosis developed by the UCLA team. Including low-cost optical readout and diagnostics based on consumer-electronic devicesmicrofluidic-based automation and molecular assays leveraging DNA nanotechnology.

This interdisciplinary work was supported through a team science grant from the National Science Foundation Emerging Frontiers in Research and Innovation program.

 

Source: UCLA

Nanoscale refrigerator helps quantum computers keep their cool

by @ newatlas.com:

The next big breakthrough for electronics is likely to be quantum computers, which will increase digitized memory capacity exponentially and allow scientists to start tackling problems that our classical computers have no hope of handling right now. Companies like IBM are starting to make some headway, but there are still plenty of hurdles to jump before practical quantum computers become a reality. A team from Aalto University in Finland may have cleared one of those obstacles, developing a nanoscale refrigerator to help cool components down.

Nanoscale refrigerator helps quantum computers keep their cool – [Link]

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