#Toward tiny, solar-powered sensors The latest buzz in the information technology industry regards he Internet of thingsthe idea that vehicles, appliances, civil-engineering structures, manufacturing equipment,
and even livestock would have embedded their own sensors that report information directly to networked servers,
however, will require extremely low-power sensors that can run for months without battery changes or, even better,
this new chip can do both, and it can power the device directly from the battery.
All of those operations also share a single inductor the chip main electrical component which saves on circuit board space
the chip power consumption remains low. e still want to have battery-charging capability, and we still want to provide a regulated output voltage,
and we really want to do all these tasks with inductor sharing and see which operational mode is the best.
The prototype chip was manufactured through the Taiwan Semiconductor Manufacturing Company's University Shuttle Program. Ups and downs The circuit chief function is to regulate the voltages between the solar cell, the battery,
To control the current flow across their chip, El-Damak and her advisor, Anantha Chandrakasan,
the Joseph F. and Nancy P. Keithley Professor in Electrical engineering, use an inductor, which is a wire wound into a coil.
When a current passes through an inductor, it generates a magnetic field which in turn resists any change in the current.
Throwing switches in the inductor path causes it to alternately charge and discharge, so that the current flowing through it continuously ramps up
however, the switches in the inductor path need to be thrown immediately; otherwise, current could begin to flow through the circuit in the wrong direction,
El-Damak and Chandrakasan use an electrical component called a capacitor, which can store electrical charge.
The higher the current, the more rapidly the capacitor fills. When it full, the circuit stops charging the inductor.
The rate at which the current drops off however, depends on the output voltage, whose regulation is the very purpose of the chip.
Since that voltage is fixed, the variation in timing has to come from variation in capacitance.
El-Damak and Chandrakasan thus equip their chip with a bank of capacitors of different sizes.
As the current drops, it charges a subset of those capacitors, whose selection is determined by the solar cell voltage.
Once again, when the capacitor fills, the switches in the inductor path are flipped. n this technology space,
there usually a trend to lower efficiency as the power gets lower, because there a fixed amount of energy that consumed by doing the work,
who leads a power conversion development project as a fellow at the chip manufacturer Maxim Integrated. f youe only coming in with a small amount,
he adds. t really kind of a full system-on-a chip for power management. And that makes it a little more complicated
#Nanoparticle network could bring fast-charging batteries (Phys. org) A new electrode design for lithium-ion batteries has been shown to potentially reduce the charging time from hours to minutes by replacing the conventional graphite electrode with a network of tin-oxide nanoparticles.
Batteries have called two electrodes an anode and a cathode. The anodes in most of today's lithium-ion batteries are made of graphite.
The researchers took a page from the paper industry using one of its processes to make a flat mesh out of light-absorbing semiconductor nanowires that
When associate professor Qi Hua Fan of the electrical engineering and computer science department set out to make a less expensive supercapacitor for storing renewable energy he developed a new plasma technology that will streamline the production of display screens.
if biochar a byproduct of the a process that converts plants materials into biofuel could be used in place of expensive activated carbon to make electrodes for supercapacitors.
The amount of charge stored in a capacitor depends on the surface area Fan explained and the biochar nanoparticles can create an extremely large surface area
The technique that treats biochar electrodes for supercapacitors can also be used in making displays explained Fan who was a research scientist at Wintek more than 10 years ago.
Plasma processing is a very critical technology in modern optoelectronic materials and devices Fan explained.
The high-energy plasma can deposit highly transparent and conductive thin films create high quality semiconductors and pattern micro-or nanoscale devices thus making the display images brighter and clearer.
#Scientists grow a new challenger to graphene A team of researchers from the University of Southampton's Optoelectronics Research Centre (ORC) has developed a new way to fabricate a potential challenger to graphene.
Graphene a single layer of carbon atoms in a honeycomb lattice is increasingly being used in new electronic and mechanical applications such as transistors switches
and related materials rather than just microscopic flakes as previously was the case greatly expands their promise for nanoelectronic and optoelectronic applications.
and hydrogen by combining these proteins with titanium dioxide and platinum and then exposing them to ultraviolet light.
titanium dioxide only reacts in the presence of ultraviolet light, which makes up a mere four percent of the total solar spectrum.
and connect with the titanium dioxide catalyst: in short, a material like graphene. Graphene is a super strong, super light, near totally transparent sheet of carbon atoms and one of the best conductors of electricity ever discovered.
Electrons from this reaction are transmitted to the titanium dioxide on which these two materials are anchored, making the titanium dioxide sensitive to visible light.
Simultaneously, light from the green end of the solar spectrum triggers the br protein to begin pumping protons along its membrane.
which sit on top of the titanium dioxide. Hydrogen is produced by the interaction of the protons and electrons as they converge on the platinum.
#Ultra-thin high-speed detector captures unprecedented range of light waves New research at the University of Maryland could lead to a generation of light detectors that can see below the surface of bodies walls and other objects.
Using the special properties of graphene a two-dimensional form of carbon that is only one atom thick a prototype detector is able to see an extraordinarily broad band of wavelengths.
A research paper about the new detector was published Sunday September 07 2014 in Nature Nanotechnology.
Lead author Xinghan Cai a University of Maryland physics graduate student said a detector like the researchers'prototype could find applications in emerging terahertz fields such as mobile communications medical imaging chemical sensing
however in part because it is difficult to detect light waves in this Range in order to maintain sensitivity most detectors need to be kept extremely cold around 4 Kelvin or-452 degrees Fahrenheit.
Existing detectors that work at room temperature are bulky slow and prohibitively expensive. The new room temperature detector developed by the University of Maryland team
and colleagues at the U s. Naval Research Lab and Monash University Australia gets around these problems by using graphene a single layer of interconnected carbon atoms.
Using a new operating principle called the hot-electron photothermoelectric effect the research team created a device that is as sensitive as any existing room temperature detector in the terahertz range
Graphene a sheet of pure carbon only one atom thick is suited uniquely to use in a terahertz detector
The concept behind the detector is simple says University of Maryland Physics Professor Dennis Drew.
The speed and sensitivity of the room temperature detector presented in this research opens the door to future discoveries in this in-between zone.
#Team develops ultra sensitive biosensor from molybdenite semiconductor Move over graphene. An atomically thin two-dimensional ultrasensitive semiconductor material for biosensing developed by researchers at UC Santa barbara promises to push the boundaries of biosensing technology in many fields from health care to environmental protection to forensic industries.
Based on molybdenum disulfide or molybdenite (Mos2) the biosensor materialsed commonly as a dry lubricanturpasses graphene's already high sensitivity offers better scalability
The key according to UCSB professor of electrical and computer engineering Kaustav Banerjee who led this research is Mos2's band gap the characteristic of a material that determines its electrical conductivity.
Semiconductor materials have a small but nonzero band gap and can be switched between conductive and insulated states controllably.
The larger the band gap the better its ability to switch states and to insulate leakage current in an insulated state.
Mos2's wide band gap allows current to travel but also prevents leakage and results in more sensitive and accurate readings.
While graphene has attracted wide interest as a biosensor due to its two-dimensional nature that allows excellent electrostatic control of the transistor channel by the gate
and high surface-to-volume ratio the sensitivity of a graphene field-effect transistor (FET) biosensor is restricted fundamentally by the zero band gap of graphene that results in increased leakage current leading to reduced sensitivity explained Banerjee
who is also the director of the Nanoelectronics Research Lab at UCSB. Graphene has been used among other things to design FETSEVICES that regulate the flow of electrons through a channel via a vertical electric field directed into the channel by a terminal called a gate.
In digital electronics these transistors control the flow of electricity throughout an integrated circuit and allow for amplification and switching.
In the realm of biosensing the physical gate is removed and the current in the channel is modulated by the binding between embedded receptor molecules and the charged target biomolecules to
despite graphene's excellent characteristics its performance is limited by its zero band gap. Electrons travel freely across a graphene FETENCE it cannot be switched offhich in this case results in current leakages and higher potential for inaccuracies.
or by introducing defects in the graphene layerr using bilayer graphene stacked in a certain pattern that allows band gap opening upon application of a vertical electric fieldor better control and detection of current.
Enter Mos2 a material already making waves in the semiconductor world for the similarities it shares with graphene including its atomically thin hexagonal structure and planar nature as well as
act like a semiconductor. Monolayer or few-layer Mos2 have a key advantage over graphene for designing an FET biosensor:
They have a relatively large and uniform band gap (1. 2-1. 8 ev depending on the number of layers) that significantly reduces the leakage current
and at the same time possess band gap they are not suitable for low-cost mass production due to their process complexities she said.
great electrostatics due to their ultra-thin body scalability (due to large band gap) as well as patternability due to their planar nature that is essential for high-volume manufacturing said Banerjee.
An Mos2-based ph sensor achieving sensitivity as high as 713 for a ph change by one unit
At present the scientific community worldwide is actively seeking practical applications of 2d semiconductor materials such as Mos2 nanosheets.
New rapid synthesis developed for bilayer graphene and high-performance transistors More information: ACS Nano pubs. acs. org/doi/abs/10.1021/nn500914 i
#Scientists craft atomically seamless thinnest-possible semiconductor junctions Scientists have developed what they believe is the thinnest-possible semiconductor,
a new class of nanoscale materials made in sheets only three atoms thick. The University of Washington researchers have demonstrated that two of these single-layer semiconductor materials can be connected in an atomically seamless fashion known as a heterojunction.
This result could be the basis for next-generation flexible and transparent computing, better light-emitting diodes,
or LEDS, and solar technologies.""Heterojunctions are fundamental elements of electronic and photonic devices, "said senior author Xiaodong Xu, a UW assistant professor of materials science and engineering and of physics."
"Our experimental demonstration of such junctions between two-dimensional materials should enable new kinds of transistors, LEDS, nanolasers,
and solar cells to be developed for highly integrated electronic and optical circuits within a single atomic plane."
The researchers discovered that two flat semiconductor materials can be connected edge-to-edge with crystalline perfection.
which was key to creating the composite two-dimensional semiconductor. Collaborators from the electron microscopy center at the University of Warwick in England found that all the atoms in both materials formed a single honeycomb lattice structure, without any distortions or discontinuities.
thinnest-possible semiconductor junctions A high-resolution scanning transmission electron microscopy (STEM) image shows the lattice structure of the heterojunctions in atomic precision.
"Scientists craft atomically seamless, thinnest-possible semiconductor junctions With a larger furnace, it would be possible to mass-produce sheets of these semiconductor heterostructures,
the researchers said. On a small scale, it takes about five minutes to grow the crystals, with up to two hours of heating and cooling time."
"In the future, combinations of two-dimensional materials may be integrated together in this way to form all kinds of interesting electronic structures such as in-plane quantum wells and quantum wires, superlattices, fully functioning transistors,
and even complete electronic circuits.""The researchers have demonstrated already that the junction interacts with light much more strongly than the rest of the monolayer,
#On the frontiers of cyborg science No longer just fantastical fodder for sci-fi buffs, cyborg technology is bringing us tangible progress toward real-life electronic skin, prosthetics and ultraflexible circuits.
pioneering scientists are working on the seamless marriage between electronics and brain signaling with the potential to transform our understanding of how the brain worksnd how to treat its most devastating diseases.
ultraflexible electronics into the brain and allow them to become fully integrated with the existing biological web of neurons.
Fortunately researchers have pinpointed now the breaking mechanism of several monolayer materials hundreds of times stronger than steel with exotic properties that could revolutionize everything from armor to electronics.
and whether they acted as metals semiconductors or insulators under strain. Toggling between or sustaining those conductive properties are particularly important for future applications in microelectronics.
Testing all the different atomic configurations for each material under strain boils down to a tremendous amount of computation Isaacs said.
to close the gap between nanowires in an array to make them useful for high-performance electronics applications.
Nanowires are extremely fast, efficient semiconductors, but to be useful for electronics applications, they need to be packed together in dense arrays.
Researchers have struggled to find a way to put large numbers of nanowires together so that they are aligned in the same direction and only one layer thick."
Smartcitizen. methese sensor enhanced hive designs are open and freely available online the data collected from each hive is published together with geolocations allowing for a further comparison and analysis of the hives.
or hobbyist and handy with electronics you get a double-whammy: a free design for a high-tech beehive that can monitor your bees'environment
In this case the microwave-harvesting metamaterial that acts kind of like a solar panel converting microwaves into up to 7. 3 volts of electricity enough to charge small electronics.
T. C. Chang Professor of Computer science at Columbia Engineering, has invented a prototype video camera that is the first to be fully self-poweredt can produce an image each second, indefinitely, of a well-lit indoor scene.
Digital imaging is expected to enable many emerging fields including wearable devices, sensor networks, smart environments, personalized medicine,
At the heart of any digital camera is an image sensor, a chip with millions of pixels.
Nayar, working with research engineer Daniel Sims BS'14 and consultant Mikhail Fridberg of ADSP Consulting, used off-the-shelf components to fabricate an image sensor with 30x40 pixels.
and uses just two transistors. During each image capture cycle, the pixels are used first to record
and charge the sensor's power supplyhe image sensor continuously toggles between image capture and power harvesting modes.
Nayar notes that the image sensor could use a rechargeable battery and charge it via its harvesting capability:"
"But we took an extreme approach to demonstrate that the sensor is indeed truly self-powered
and used just a capacitor to store the harvested energy.""""A few different designs for image sensors that can harvest energy have been proposed in the past.
However, our prototype is the first demonstration of a fully self-powered video camera, "he continues."
"And, even though we've used off-the-shelf components to demonstrate our design, our sensor architecture easily lends itself to a compact solid-state imaging chip.
We believe our results are a significant step forward in developing an entirely new generation of cameras that can function for a very long durationdeally,
ingestible electronics, which can diagnose and monitor a variety of conditions in the GI TRACT; or extended-release drug-delivery systems that could last for weeks
researchers from the Pohang University of Science and Technology detail how they were able to turn black phosphorus into a superior conductor that can be mass produced for electronic and optoelectronics devices.
affiliated with the Institute for Basic Science (IBS) Center for Artificial Low Dimensional Electronic systems (CALDES), reported a tunable band gap in BP,
This research outcome potentially allows for great flexibility in the design and optimization of electronic and optoelectronic devices like solar panels and telecommunication lasers.
This amalgamation makes it a terrifically attractive material to apply to scientific developments in a wide variety of fields, such as electronics, aerospace and sports.
graphene has no band gap. Stepping stones to a Unique Statea material band gap is fundamental to determining its electrical conductivity.
Imagine two river crossings, one with tightly-packed stepping-stones, and the other with large gaps between stones.
A band gap is much the same; the smaller the gap the more efficiently the current can move across the material and the stronger the current.
Graphene has a band gap of zero in its natural state, however, and so acts like a conductor;
the semiconductor potential can be realized because the conductivity can be shut off, even at low temperatures. This obviously dilutes its appeal as a semiconductor,
as shutting off conductivity is a vital part of a semiconductor function. Birth of a Revolutionphosphorus is the fifteenth element in the periodic table
and lends its name to an entire class of compounds. Indeed it could be considered an archetype of chemistry itself.
Like graphene, BP is a semiconductor and also cheap to mass produce. The one big difference between the two is BP natural band gap
allowing the material to switch its electrical current on and off. The research team tested on few layers of BP called phosphorene
which is required what we to tune the size of the band gap. his process of transferring electrons is known as doping
which tuned the band gap allowing the valence and conductive bands to move closer together, effectively lowering the band gap
and drastically altering it to a value between 0. 0 0. 6 Electron volt (ev) from its original intrinsic value of 0. 35 ev.
It more efficient in its natural state than black phosphorus but it difficult to open its band gap;
therefore we tuned BP band gap to resemble the natural state of graphene, a unique state of matter that is different from conventional semiconductors. he potential for this new improved form of black phosphorus is beyond anything the Korean team hoped for,
and very soon it could potentially be applied to several sectors including engineering where electrical engineers can adjust the band gap
and create devises with the exact behavior desired. The 2-D revolution, it seems, has arrived and is here for the long run.
bservation of tunable bandgap and anisotropic Dirac semimetal state in black phosphorus, Science 14 august 2015:
Applications of these devices include advanced microscopes, displays, sensors, and cameras that can be mass-produced using the same techniques used to manufacture computer microchips. hese flat lenses will help us to make more compact and robust imaging assemblies,
said Mahmood Bagheri, a microdevices engineer at JPL and co-author of a new Nature Nanotechnology study describing the devices. urrently,
and the study principal investigator. ut this new technology is very similar to the one used to print semiconductor chips onto silicon wafers,
so you could conceivably manufacture millions of systems such as microscopes or cameras at a time. een under a scanning electron microscope,
Semiconductor lasers typically emit into elliptical beams that are really hard to work with and the new metasurface optical components could replace expensive optical systems used to circularize the beams.
The nanoparticle hydrophilic layer essentially locks in the active ingredient, a hydrophobic chemical called padimate O. Some sunscreen solutions that use larger particles of inorganic compounds, such as titanium dioxide or zinc oxide,
#Tunnel Transistor May Meet Power Needs of Future Chips A new kind of transistor consumes 90 percent less power than conventional transistors,
dramatically exceeding a theoretical limit for electronics, researchers say. These findings could one day lead to super-dense low-power circuits as well as ultra-sensitive biosensors and gas sensors, the investigators added.
The relentless advance of computing power over the past half-century has relied on constant miniaturization of field-effect transistors (FETS),
which serve as the building blocks of most microchips. Transistors act like switches that flick on and off to represent data as zeroes and ones.
A key challenge that FETS now face is reducing the power they consume. The switching properties of conventional FETS are restricted currently by a theoretical limit of 60 millivolts per decade of current at room temperature.
This limit, known as the subthreshold swing, means that each 60-millivolt increase in voltage leads to a 10-fold increase in current.
This led to a more than 90 percent reduction in power consumption compared with conventional FETS. The scientists and engineers detailed their findings in the 1 oct. issue of the journal Nature. his transistor represents a major breakthrough in the electronics and semiconductor industry
ays study co-author Kaustav Banerjee, an electrical engineer at UCSB. The new TFET is made from two atomically-thin layers of semiconducting molybdenum sulfide crystal on top of a substrate of germanium.
Until now, the only experimental TFET to meet the International Technology Roadmap for Semiconductors (ITRS) goal of average subthreshold swing below 60 millivolts per decade over four decades of current was a transistor that used nanowires.
But that type is often challenging to fabricate using conventional semiconductor manufacturing techniques. This new TFET not only meets the ITRS goal
UCSB Banerjee suggests that potential applications for these new TFETS may include ultra-low-power electronics and computing,
and ultra-sensitive and low-power biosensors and gas sensors to enhance the Internet of things. However, Banerjee cautions that TFETS are designed not for speed
or high performance. hey are desirable for low-power electronics, e says
#Airware Launches Its Commercial Drone Operating system Drones could save businesses big money by doing dull, dirty,
this new system will let customers take advantage of more advanced sensor and image processing tools without sacrificing an interface that actually usable for operators in the field.
They could also put this into many different devices, such as wearable technology, embedded sensors, medical devices and Internet of things devices anything that doesn require massive amounts of electricity.
This is again the case with a 3d printed solution for a problem almost as old as robots equipped with microphones themselves:
or equipping robots with a large number of microphones focused on various positions in the vicinity,
and diverse honeycomb passages leading to a single microphone in the center of the disk.
It is essentially a single-sensor listening system that combines acoustic metamaterials and compressive sensing techniques. ifferent from previous research efforts that generally rely on signal
Well each of the 46 passages to the microphone is unique and features subtly different ways of enabling sound to travel to the center,
because the unique 3d printed shapes create variations that can be picked up by the single sensor.
but the algorithm used for the sensor can almost always tell which direction it comes from.
which houses control electronics and the video camera holder. According to the engineers, who published their breakthrough research in the journal HKIE Transactions
Its applications range from medicine, advanced energy, electronics, aerospace design and many others. Despite these groundbreaking characteristics,
The company is a worldwide leader in the manufacurting and retailing of graphene and other advanced materials, with clients such as NASA, Ford motor, Apple, Samsung, Harvard and Stanford.
and will allow an ever widening variety of manufacturers to consider incorporating the extraordinary qualities of graphene in wide range of materials from batteries to consumer electronics to plastics. s the most sought-after and groundbreaking material,
What makes this printer so efficient is its digital micromirroring array device chip (DMD), containing millions of micromirrors that function separately from one another to cast the desired microfish design onto photosensitive material,
will be able to serve as both a detoxification device and a toxin sensor too, and, hopefully,
randomly oriented fibers that only can be seen with electron microscopes. These nanomembranes have a high surface-to-volume ratio
The existing sensor technologies generally need the nucleic acid to be purified. This would entail performing several steps
Going forward, the team anticipates that their research will be useful in the progress of mini point-of-care diagnostic systems for clinical and agricultural applications. he applications of the sensor are quite broad ranging from detection of plant pathogens to disease biomarkers,
The existing sensor technologies generally need the nucleic acid to be purified. This would entail performing several steps
Going forward, the team anticipates that their research will be useful in the progress of mini point-of-care diagnostic systems for clinical and agricultural applications. he applications of the sensor are quite broad ranging from detection of plant pathogens to disease biomarkers,
#Smart sensor developed by Duke university, lets your smartphone hear in noisy parties People trying to talk to Apple electronic personal assistant Siri in a crowded place may soon no longer have to look like they are about to eat their iphones,
The sensor developed by Duke engineers can determine the direction of a sound and extract it from the surrounding background noise.
the device could have applications in voice-command electronics, medical sensing devices that use waves, like ultrasound,
After being picked up by a microphone on the other side, the sound is transmitted to a computer that is able to separate the jumble of noises based on these unique distortions.
The researchers tested their invention in multiple trials by simultaneously sending three identical sounds at the sensor from three different directions.
Duke university, Research, smart sensors, sound sensor s
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