and n-type semiconductors silicon that has either more positive or more negative charge carriers. The junctions between p-and n-type semiconductors are the building blocks of electronic devices.
Put together in sequence these p-n junctions form transistors which can in turn be combined into integrated circuits microchips and processors.
Chemically doping graphene to achieve p -and n-type version of the material is possible but it means sacrificing some of its unique electrical properties.
but manufacturing and placing the necessary electrodes negates the advantages graphene's form factor provides.
what p-n junctions and complementary circuitry has done for the current state-of-the-art semiconductor electronics. What's even more exciting are the enabling of optoelectronics using graphene
and the possibility of waveguiding lensing and periodically manipulating electrons confined in an atomically thin material.
This ability would represent an advantage over chemically doped semiconductors. Once the atomic impurities are mixed into the material to change its carrier density they can't be removed.
It shows the presence of jagged ligands can give rise to sender/receiver hybrid cells that send a signal--be like
The other (the receiver) expresses low notch and high delta. This situation leads the two cells to adopt opposite fates:
It also generates small amounts of electricity--in practice enough to drive a small fan, a sensor or a light-emitting diode.
but which could also transfer electrons to a metal electrode, "he says. The idea behind this water purification approach was born many years ago
MBI uses small semiconductor-based gamma cameras to image the breast following injection of a radiotracer that tumors absorb avidly.
"We're going to make this material much more active by integrating smart materials like microchips that are controllable.
"Going forward, Huang said there are numerous possibilities for the material to control elastic waves including super-resolution sensors, acoustic and medical hearing devices,
wafer-scale single-crystalline semiconductors grown by sophisticated, high temperature crystal-growth processes are seen as the future of efficient solar technology.
"and we've demonstrated that the crystalline quality is on par with that observed for high-quality semiconductors like silicon and gallium arsenides."
In addition, it may be used as an advanced substrate and for encapsulation of oxygen-sensitive organic electronics in flexible displays a
which was developed by researchers from the University's Optoelectronics Research Centre (ORC) has potential applications in a number of fields that use pulsed lasers including telecommunications metrology sensing and material processing.
It relies upon the coherent combination of multiple semiconductor lasers each operating continuous-wave at different precisely defined frequencies (wavelengths.
The key to making the approach work is to phase-lock the semiconductor lasers to an optical frequency comb
Finally it consists of miniature and low-cost semiconductor lasers that can be integrated all on the same chip making our pulse generator potentially very compact robust energetically efficient and low-cost.
Empa and the University Hospital Zurich thus teamed up to develop the sensor"Glucolight,""which gages the blood sugar level through the skin,
Although skin sensors already exist, they have to be calibrated before use, which means that the skin's permeability value needs to be known.
and the sensor calibrated. A different method to previous sensors Glucolight spares the premature babies blood samples
and enables the blood sugar level to be monitored permanently thanks to the sensor's novel measuring technology,
which comprises several parts: A microdialysis measuring head, which was developed at the University Hospital Zurich,
and pumped through the microfluidics chip, while enzymes are added to trigger a reaction. During the reaction, a fluorescence appears, which the fluorometer measures,
Empa and the University Hospital Zurich are currently in negotiations with partners for the industrial production of the sensor.
and increasing the brightness of light-emitting diodes.""For antireflection applications, the idea is to prevent light
The self-assembled pattern served as a template for forming posts in the solar cell like those in the moth eye using a plasma of reactive gases-a technique commonly used in the manufacture of semiconductor electronic circuits.
Guo's team is now planning on focusing on increasing the speed of patterning the surfaces with the laser as well as studying how to expand this technique to other materials such as semiconductors
or dielectrics opening up the possibility of water repellent electronics. Funding was provided by the Bill & Melinda Gates Foundation and the United states Air force Office of Scientific research h
#New laser for computer chips: International team of scientists constructs first germanium-tin semiconductor laser for silicon chips The transfer of data between multiple cores as well as between logic elements and memory cells is regarded as a bottleneck in the fast-developing computer technology.
Data transmission via light could be the answer to the call for a faster and more energy efficient data flow on computer chips as well as between different board components.
Signal transmission via copper wires limits the development of larger and faster computers due to the thermal load and the limited bandwidth of copper wires.
The clock signal alone synchronizing the circuits uses up to 30%of the energy--energy which can be saved through optical transmission explains Prof.
They allow very high bandwidths even over long distances. Through optical fibres signal propagation is almost lossless and possible across various wavelengths simultaneously:
However in spite of intensive research a laser source that is compatible with the manufacturing of chips is not yet achievable according to the head of Semiconductor Nanoelectronics (PGI-9). The basis of chip manufacturing is silicon an element of main group IV of the periodic table.
Typical semiconductor lasers for telecommunication systems made of gallium arsenide for example however are costly and consist of elements from main groups III
In contrast semiconductors of main group IV--to which both silicon and germanium belong--can be integrated into the manufacturing process without any major difficulties.
They are classed among the indirect semiconductors. In contrast to direct semiconductors they emit mostly heat and only a little light when excited.
That is why research groups all over the globe are intensively pursuing the objective of manipulating the material properties of germanium
The scientists at Julich's Peter Grunberg Institute have succeeded now for the first time in creating a real direct main group IV semiconductor laser by combining germanium and tin
Currently the scientists in Dr. Dan Buca's group at Julich are working on linking optics and electronics even more closely.
Hence sensors made of Gesn promise a new possibility of detecting these compounds. Along with computer chips completely new applications that have not been pursued so far for financial reasons may
thus benefit from the new laser material. Gas sensors or implantable chips for medical applications which can gather information about blood sugar levels
or other parameters via spectroscopic analysis are examples. In the future cost-effective portable sensor technology--which may be integrated into a smart phone--could supply real-time data on the distribution of substances in the air
or the ground and thus contribute to a better understanding of weather and climate development m
computer chips, and the nanomaterials involved in energy conversion or storage. But this also means that the X-rays pass straight through conventional lenses without being bent or focussed.
"This will put X-ray imaging on par with the quality achieved with scanning electron microscopes, that typically have a resolution of 4 nm.
The final pump sources are being evaluated for potential use in high-energy-class diode-pumped solid-state laser systems together with the world-leading groups in the field
"SINTEF has been involved for several years in projects involving x-ray methods and x-ray detectors, and has obtained know-how about their uses for a variety of purposes,
Jérôme Bonnet's team in Montpellier's Centre for Structural Biochemistry (CBS) had the idea of using concepts from synthetic biology derived from electronics to construct genetic systems making it possible to"programme"living cells like a computer.
the cornerstone of genetic programming The transistor is the central component of modern electronic systems. It acts both as a switch and as a signal amplifier.
In informatics, by combining several transistors, it is possible to construct"logic gates, "i e. systems that respond to different signal combinations according to a predetermined logic.
For example, a dual input"AND"logic gate will produce a signal only if two input signals are present.
All calculations completed by the electronic instruments we use every day, such as smartphones, rely on the use of transistors and logic gates.
During his postdoctoral fellowship at Stanford university in the United states Jérôme Bonnet invented a genetic transistor, the transcriptor.
The insertion of one or more transcriptors into bacteria transforms them into microscopic calculators. The electrical signals used in electronics are replaced by molecular signals that control gene expression.
It is thus now possible to implant simple genetic"programmes"into living cells in response to different combinations of molecules.
In this new work, the teams led by Jérôme Bonnet (CBS, Inserm U1054, CNRS UMR5048, Montpellier University), Franck Molina (Sysdiag, CNRS FRE 3690),
As a proof of concept, the authors connected the genetic transistor to a bacterial system that responds to glucose,
Arraysuperconductors are regarded as one of the most promising candidates for next-generation advanced electronic devices, because the unique quantum effects in superconductors are a great advantage in achieving the energy saving
--273°C)* 1. It has also been a big challenge to realize the high-density integration of superconductors into electronic devices.
The ultrathin high-Tc superconductor would effectively contribute to the significant downsizing and consequent high-density integration in electric circuits,
leading to the realization of future-generation electronic devices with high energy-saving and ultrahigh-speed operation.
Carlos Castro tells Sinc, in a telephone interview from the Research Laboratory of Electronics of MIT in Boston,
the print features are very fine--visible only with the aid of a high-powered electron microscope.
Under a scanning electron microscope, the template looks like a needlepoint pattern of the logo. The researchers then beamed light through the holes to create the logo using no ink--only the interaction of the materials and light.
A leader and follower controlled dots on a screen, using hand-held motion tracking sensors. The leader was taught to produce chaotic and unpredictable movements,
and demonstrating what they call the"world's first fully functioning single crystal waveguide in glass."
The article, published May 19, is titled"Direct laser-writing of ferroelectric single-crystal waveguide architectures in glass for 3d integrated optics."
The group says its achievement will boost ongoing efforts to develop photonic integrated circuits (PICS) that are smaller, cheaper, more energy-efficient and more reliable than current networks that use discrete optoelectronic components--waveguides, splitters, modulators, filters
, amplifiers--to transport optical signals.""A major trend in optics,"the researchers write, "has been a drive toward...
in much the same way that integration of electronics has driven the impressive advances of modern computer systems."
"Amorphous waveguides fundamentally lack second-order optical nonlinearity due to their isotropically disordered atomic structure, "the researchers write,
and heat at the nanoscale, addressing the fundamental limits of ultrafast spintronic devices for data storage and information processing.
In addition to Choi and Cahill--whose work was supported by the Army Research Office MURI program--co-authors of the paper include Byoung-Chul Min, Center for Spintronics Research, Korea Institute of Science and Technology, Seoul;
which in turn led to the researchers determining the vital role played by CXCR4-CXCL12 molecular signaling in disease growth.
Deletion of the CXCR4 gene led to sustained T-ALL remission within a month in similar mice,
we've demonstrated that we can make all the universal logic gates used in electronics, simply by changing the layout of the bars on the chip,
"said Katsikis.""The actual design space in our platform is incredibly rich. Give us any Boolean logic circuit in the world,
and demonstrates building blocks for synchronous logic gates, feedback and cascadability--hallmarks of scalable computation. A simple-state machine including 1-bit memory storage (known as"flip-flop")is demonstrated also using the above basic building blocks.
Arraythe current chips are about half the size of a postage stamp, and the droplets are smaller than poppy seeds,
and do more number of operations on a chip, "said graduate student and co-author Jim Cybulski."
serving as a kind of thermostat to ensure that proper levels are maintained.''Precisely controlling glucose transport is critical to health,
and I lit up this small LED,"he says.""At that moment, I knew I had done it
MEMS are fabricated microscale devices using silicon wafers in facilities that make integrated circuits. The MEMS device acts as an ultrafast mirror reflecting X-rays at precise times and specific angles."
#Graphene quantum dot LEDS Graphene is a 2d carbon nanomaterial with many fascinating properties that can enable to creation of next-generation electronics.
However, it is known that graphene is not applicable to optical devices due to its lack of an electronic band gap.
Seunghyup Yoo (Electrical engineering) have succeeded in developing LEDS based on graphene quantum dots. Highly pure GQDS were synthesized by an environmentally-friendly method designed by Prof.
Yoo's group brought their OLED expertise to create GQD-based LEDS. The GQDS with high luminance tunability and efficiency were synthesized by a route based on graphite intercalation compounds (GICS.
GQDS were used then as emitters in organic light-emitting diodes (OLEDS) in order to identify the GQD's key optical properties.
the constructed GQD LEDS exhibited luminance of 1, 000 cd/m2, which is well over the typical brightness levels of the portable displays used in smartphones.
for the first time, demonstrated that GQDS can be applied to optical devices by fabricating GQD-based LEDS with meaningful brightness.
Although, the efficiency of GQD-based LEDS is currently less than those of conventional LEDS, they are expected to improve in the near future with an optimized material process and device structure.
that is perfectly suited for the delicate work involved in semiconductor manufacturing. Like the gecko, the gripper has"tunable adhesion,
#Comprehensive know-how and the full value chain, from technology development to complete systems Arraythe FBH develops the LED TECHNOLOGY in the UV-B and UV-C spectral range from the chip to the final
In this particular case, LEDS emitting at a wavelength around 310 nm are used to stimulate health-promoting secondary metabolites in plants.
which are defined by gratings implemented into the semiconductor chip. Wavelength selection is realized by separately addressable sections within the laser.
With these FBH tiny monolithic light sources on chip level, a compact SERDS measurement head that is only as small as a laser pointer was realized for the first time.
For rapid prototyping applications the FBH has developed DBR ridge waveguide (RW) lasers with 24 individually addressable emitters featuring a wavelength spacing>0. 3 nm and a spectral width<1 pm.
and protective properties that make it well-suited for a range of biomedical and optoelectronic applications.
suggest that the excellent properties of the solar cell result from an additional mechanism--the formation of indirect band gaps--that plays an important role in photovoltaics.
high efficiency resulting from an indirect electronic band gap?.""The clou is that we just need a single organic molecule in the solar cell,
#A diode a few atoms thick shows surprising quantum effect A quantum mechanical transport phenomenon demonstrated for the first time in synthetic,
The potential of NDR lies in low voltage electronic circuits that could be operated at high frequency.""Theory suggests that stacking two-dimensional layers of different materials one atop the other can lead to new materials with new phenomena,
The paper is titled"Atomically Thin Resonant Tunnel Diodes Built from Synthetic Van der waals Heterostructures.""Achieving NDR in a resonant tunneling diode at room temperature requires nearly perfect interfaces,
which are possible using direct growth techniques, in this case oxide vaporization of molybdenum oxide in the presence of sulfur vapor to make the Mos2 layer,
they consulted an expert in nanoscale electronic devices, Suman Datta, who told them they were seeing a 2d version of a resonant tunneling diode,
a quantum mechanical device that operates at low power.""Resonant tunnel diodes are important circuit components, "says Datta, a coauthor on the paper and Penn State professor of electrical engineering."
"Resonant tunneling diodes with NDR can be used to build high frequency oscillators. What this means is we have built the world's thinnest resonant tunneling diode,
and it operates at room temperature!""Coauthor Robert Wallace of the University of Texas at Dallas says this collaborative work represents an important achievement in the realization of useful 2d integrated circuits."
"The ability to observe the resonant behavior at room temperature with synthesized 2d materials rather than exfoliated,
stacked flakes is exciting as it points toward the possibilities for scalable device fabrication methods that are more compatible with industrial interests.
The UT-Dallas coauthors provided the detailed atomic resolution materials characterization for the resonant tunneling diodes discovered at Penn State.
Datta cautions that the new resonant tunnel diode is just one element in a circuit
and integrating the other circuit elements, such as transistors, in 2d.""The take home message,"he says,
"is that this gives us a nugget that we as device and circuit people can start playing around with and build useful circuits for 2d electronics."
The work was performed in conjunction with the Center for Two-dimensional and Layered Materials (2dlm) at Penn State and supported by the Semiconductor Research Corporation and DARPA through the Center for Low energy Systems Technology.
'Many previous studies have indicated that AIM2 contributes to the immune system by acting as a pathogen sensor,
based on studies from Kanneganti's lab and others indicating that microbial sensors similar to AIM2 contributed to healthy gut microbiota.
The fabrication of the optical cavities relied on a new silicon hard-mask fabrication process that applies mature semiconductor fabrication methods for patterning high-quality photonic devices into unconventional substrates.
Electronic systems are expected to process and store a steadily increasing amount of data, faster and faster,
Luckily, physicists discover effects that help engineers to develop better electronic components with surprising regularity, for instance a phenomenon known as giant magnetoresistance.
This is a procedure where the inside of the body is examined using a probe with a light source and video camera at the end via the mouth and down the gullet.
The researchers hope to use the findings from the clinical trial to create a sensor device that can signal to clinicians
A conventional water-splitting device consists of two electrodes submerged in a water-based electrolyte.
A low-voltage current applied to the electrodes drives a catalytic reaction that separates molecules of H2o, releasing bubbles of hydrogen on one electrode and oxygen on the other.
Each electrode is embedded with a different catalyst typically platinum and iridium, two rare and costly metals.
for both electrodes,'said graduate student Haotian Wang, lead author of the study.''This bifunctional catalyst can split water continuously for more than a week with a steady input of just 1. 5 volts of electricity.
'Arrayto find catalytic material suitable for both electrodes, the Stanford team borrowed a technique used in battery research called lithium-induced electrochemical tuning.
In this so-called"flow battery,"the electrodes are suspensions of tiny particles carried by a liquid and pumped through various compartments of the battery.
while the electrode material does not flow, it is composed of a similar semisolid, colloidal suspension of particles.
"We realized that a better way to make use of this flowable electrode technology was to reinvent the lithium ion manufacturing process."
the new process keeps the electrode material in a liquid state and requires no drying stage at all.
Using fewer, thicker electrodes, the system reduces the conventional battery architecture's number of distinct layers,
Having the electrode in the form of tiny suspended particles instead of consolidated slabs greatly reduces the path length for charged particles as they move through the material--a property known as"tortuosity."
"A less tortuous path makes it possible to use thicker electrodes, which, in turn, simplifies production
While conventional lithium-ion batteries are composed of brittle electrodes that can crack under stress, the new formulation produces battery cells that can be bent,
The system uses a miniature video camera stored in the patient's glasses to send visual information to a small computerized video processing unit which can be stored in a pocket.
This computer turns the image to electronic signals that are sent wirelessly to an electronic device implanted on the retina
and cadmium sulfide to provide a route to low-cost, scalable and green synthesis of Cds nanocrystals with extrinsic crystallite size control in the quantum confinement range.
The result is Cds semiconductor nanocrystals with associated size-dependent band gap and photoluminescent properties. This biosynthetic approach provides a viable pathway to realize the promise of green biomanufacturing of these materials.
renewable energy and optoelectronics, are typically expensive and complicated to manufacture. In particular, current chemical synthesis methods use high temperatures and toxic solvents,
or possibly a remote control, new and exciting opportunities for future research and treatment of neurological disorders can be envisaged."
Magnetic sensor 100 times more sensitive than silicon equivalent Scientists have created a graphene-based magnetic sensor 100 times more sensitive than an equivalent device based on silicon.
Bosch has long been involved in sensor technology, notably in the automotive sector. In 2008, the company expanded beyond its pressure, acceleration and gyroscopic motion sensors, to geomagnetic, temperature, humidity,
air quality and sound pressure devices, including for use in consumer electronics devices such as mobile phones. Interested in whether graphene could enable new applications and improved sensor performance,
Bosch has been investigating the use of the two-dimensional material in its pressure, magnetic, humidity, gas and sound pressure devices.
The first step was to look at fabrication methods. Top-down approaches to graphene device fabrication such as mechanical and chemical exfoliation would not work on a commercial scale,
Roelver cautioned that graphene-based sensor applications will require 5-10 years before they can compete with established technologies.
who in the case of their magnetic sensor settled on hexagonal boron nitride. This is for reasons of both cost and technical performance.
Bosch's magnetic sensors are based on the Hall effect, in which a magnetic field induces a Lorentz force on moving electric charge carriers, leading to deflection and a measurable Hall voltage.
Sensor performance is defined by two parameters:(1) sensitivity, which depends on the number of charge carriers,
In short, graphene provides for a high-performance magnetic sensor with low power and footprint requirements. In terms of hard numbers
the result shown by Roelver centred on a direct comparison between the sensitivity of a silicon-based Hall sensor with that of the Bosch-MPI graphene device.
The silicon sensor has a sensitivity of 70 volts per amp-tesla, whereas with the boron nitride and graphene device the figure is 7, 000.
#Building a better semiconductor Arraythe electrical properties of semiconductors depend on the nature of trace impurities, known as dopants,
which when added appropriately to the material will allow for the designing of more efficient solid-state electronics.
""The material we studied is an unconventional semiconductor made of alternating atomically thin layers of metals
and possibly optically controlled switching devices employing undoped semiconductor materials.""A semiconductor is a substance that conducts electricity under some conditions
but not others, making it a good medium for the control of electrical current. They are used in any number of electronics,
including computers s
#Eco-friendly oil spill solution developed An eco-friendly biodegradable green'herding'agent that can be used to clean up light crude oil spills on water has been developed by researchers.
#Ultrasonic fingerprint sensor may take smartphone security to new level A new ultrasonic fingerprint sensor measures 3-D image of your finger's surface
Fingerprint sensor technology currently used in smartphones like the iphone 6 produces a two-dimensional image of a finger's surface,
A newly developed ultrasonic sensor eliminates that risk by imaging the ridges and valleys of the fingerprint's surface,
Davis. He is a director of the Berkeley Sensor and Actuator Center, which is located on the campuses of UC Davis and the University of California,
"After Apple announced a fingerprint sensor in their new iphone in 2013, it was inevitable that more would follow,
when the teams at the Berkeley Sensor and Actuator Center collaborated to initiate research into piezoelectric-micromachined ultrasonic transducers (PMUTS)."
along with a custom application-specific integrated circuit (ASIC) and the supporting electronics,"Horsley said.""Our work was so successful that we spun off Chirp Microsystems, in 2013,
"Transducers on the chip's surface emit a pulse of ultrasound, and these same transducers receive echoes returning from the ridges and valleys of your fingerprint's surface."
"The basis for the ultrasound sensor is an array of MEMS ultrasound devices with highly uniform characteristics,
which smartphones rely on for such functions as microphones and directional orientation. They used a modified version of the manufacturing process used to make the MEMS accelerometer
and gyroscope found in the iphone and many other consumer electronics devices.""Our chip is fabricated from two wafers--a MEMS wafer that contains the ultrasound transducers
and a CMOS wafer that contains the signal processing circuitry, "explained Horsley.""These wafers are bonded together,
then the MEMS wafer is thinned'to expose the ultrasound transducers."("CMOS, or complementary metal-oxide-semiconductor, is based the silicon technology used to make transistors in microchips.
Horsley's group views ultrasound as the next frontier for MEMS technology.""Because we were able to use low-cost,
high-volume manufacturing processes that produce hundreds of millions of MEMS sensors for consumer electronics each year,
our ultrasound chips can be manufactured at an extremely low cost, "he said. The imager is powered by a 1. 8-Volt power supply,
using a power-efficient charge pump on their ASIC or application-specific integrated circuit.""Our ultrasound transducers have high sensitivity
and the receiver electronics are located directly beneath the array, which results in low electrical parasitics,"Horsley noted."
"Using low-voltage integrated circuits will reduce the cost of our sensor and open up myriad new applications where the cost, size,
and power consumption of existing ultrasound sensors are currently prohibitive.""Within the realm of biometrics and information security, the group's work is particularly significant,
"Our ultrasonic fingerprint sensors have the ability to measure a three-dimensional, volumetric image of the finger surface and the tissues beneath the surface--making fingerprint sensors more robust and secure."
"Beyond biometrics and information security purposes, the new technology is expected to find many other applications, including"low-cost ultrasound as a medical diagnostic tool or for personal health monitoring,
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