Technology category

The Next-Generation Semiconductor for Power Electronics

Researchers have demonstrated the high-performance potential of an experimental transistor made of a semiconductor called beta gallium oxide, which could bring new ultra-efficient switches for applications such as the power grid, military ships and aircraft.

The semiconductor is promising for next-generation “power electronics,” or devices needed to control the flow of electrical energy in circuits. Such a technology could help to reduce global energy use and greenhouse gas emissions by replacing less efficient and bulky power electronics switches now in use.

The schematic at left shows the design for an experimental transistor made of a semiconductor called beta gallium oxide, which could bring new ultra-efficient switches for applications such as the power grid, military ships and aircraft. At right is an atomic force microscope image of the semiconductor. (Purdue University image/Peide Ye)

 

The schematic at left shows the design for an experimental transistor made of a semiconductor called beta gallium oxide, which could bring new ultra-efficient switches for applications such as the power grid, military ships and aircraft. At right is an atomic force microscope image of the semiconductor. (Purdue University image/Peide Ye)The transistor, called a gallium oxide on insulator field effect transistor, or GOOI, is especially promising because it possesses an “ultra-wide bandgap,” a trait needed for switches in high-voltage applications.

Compared to other semiconductors thought to be promising for the transistors, devices made from beta gallium oxide have a higher “breakdown voltage,” or the voltage at which the device fails, said Peide Ye, Purdue University’s Richard J. and Mary Jo Schwartz Professor of Electrical and Computer Engineering.

Findings are detailed in a research paper published this month in IEEE Electron Device Letters. Graduate student Hong Zhou performed much of the research.

The team also developed a new low-cost method using adhesive tape to peel off layers of the semiconductor from a single crystal, representing a far less expensive alternative to a laboratory technique called epitaxy. The market price for a 1-centimeter-by-1.5-centimeter piece of beta gallium oxide produced using epitaxy is about $6,000. In comparison, the “Scotch-tape” approach costs pennies and it can be used to cut films of the beta gallium oxide material into belts or “nano-membranes,” which can then be transferred to a conventional silicon disc and manufactured into devices, Ye said.

The technique was found to yield extremely smooth films, having a surface roughness of 0.3 nano-meters, which is another factor that bodes well for its use in electronic devices, said Ye, who is affiliated with the NEPTUNE Center for Power and Energy Research, funded by the U.S. Office of Naval Research and based at Purdue’s Discovery Park. Related research was supported by the center.

The Purdue team achieved electrical currents 10 to 100 times greater than other research groups working with the semiconductor, Ye said.

One drawback to the material is that it possesses poor thermal properties. To help solve the problem, future research may include work to attach the material to a substrate of diamond or aluminum nitride.

The research was based at Discovery Park’s Birck Nanotechnology Center.
Source: Purdue University

Human Motion Powered Nanotechnology Devices

Michigan State University researchers have came up with a new method for  harvesting energy from human motion using nanotechnology. They designed a low-cost film-like device, a nanogenerator, than can power a LCD display,  keyboard, and some LEDs without any source of electric power, by only using some human touching or pressing.

This device called FENG, biocompatible ferroelectret nanogenerator, consists of several thin layers of silicon wafer made of environmentally friendly substances like silver, polyimide, and polypropylene ferroelectret – which is introduced here as the active material of this device. To add the electrical powering feature, researchers added ions to each layer to make sure that each layer has its own charged particles. Finally the circuit works only once some pressure or mechanical energy is performed on the device. For example, by using this technology you will be able to power the LED lights with the pressure of your palm, while the pressure of your finger is enough to power the LCD screen.

In this video 20 LEDs are powered with hand pressing:

Researchers’ investigations had shown that the voltage and current generated by pressure can be doubled if the device is folded, means a high-frequency pressure is already demonstrated.

“Each time you fold it you are increasing exponentially the amount of voltage you are creating,” said Nelson Sepulveda, associate professor of electrical and computer engineering and lead investigator of the project. “You can start with a large device, but when you fold it once, and again, and again, it’s now much smaller and has more energy. Now it may be small enough to put in a specially made heel of your shoe so it creates power each time your heel strikes the ground.”

Sepulveda believes that implementing this technology in real life will shift wearables to be completely powered by human motion. He and his team are working now on transmitting the power generated from the heel strike to be used for powering other devices like a headset.

In this video you can take a look at the flexible keyboard they designed:

This research was funded by the National Science Foundation. You can learn more about this project by checking the scientific paper, and the university official website.

Efficient Low-Cost Solar Energy Converter

Researchers at the École Polytechnique Fédérale de Lausanne and the Centre Suisse d’Electronique et de Microtechnique have invented a new device to store solar power while the sun’s not shining by converting it into Hydrogen. Although many current methods use the same approach to store energy, but this device rivals them in stability, efficiency and cost.

An effective and low-cost solution for storing solar energy © Infini Lab / 2016 EPFL

 

They combined commercially available components that have already proven effective in industry, such as Nickel, in order to develop a robust and effective system, that is  :made up of three interconnected, new-generation, crystalline silicon solar cells attached to an electrolysis system that does not rely on rare metals. The device is able to convert solar energy into hydrogen at a rate of 14.2%, and has already been run for more than 100 hours straight under test conditions.”

In order to develop this device, the researchers used layers of crystalline silicon and amorphous silicon to allow higher voltages. Thus, three cells in series generate a nearly ideal voltage for electrolysis.

“We wanted to develop a high performance system that can work under current conditions,” says Jan-Willem Schüttauf, a researcher at CSEM and co-author of the paper. “The heterojunction cells that we use belong to the family of crystalline silicon cells, which alone account for about 90% of the solar panel market. It is a well-known and robust technology whose lifespan exceeds 25 years. And it also happens to cover the south side of the CSEM building in Neuchâtel.”

This method, which outperforms previous efforts in terms of stability, performance, lifespan and cost efficiency, is published in the Journal of The Electrochemical Society. You can check the scientific paper here.

 

Supercapacitors Surpassing Conventional Batteries

Researchers at the University of Central Florida have been looking for alternatives for lithium rechargeable batteries which are largely used in every device.

Using two-dimensional (2D) transition-metal dichalcogenides (TMDs) capacitive materials, they are building a new supercapacitor that overcomes the performance of conventional lithium battery and replaces its efficiently.

Transition metal dichalcogenide monolayers (TMDs) are atomically thin semiconductors of the type MX₂, with M a transition metal atom and X a chalcogen atom. One layer of M atoms is sandwiched between two layers of X atoms.

TMDs are considered as promising capacitive materials for supercapacitor devices since they provide a suitable current conduction path and a robust large surface to increase the structure’s high energy and power density.

Researchers have developed “high-performance core/shell nanowire supercapacitors based on an array of one-dimensional (1D) nanowires seamlessly integrated with conformal 2D TMD layers. The 1D and 2D supercapacitor components possess “one-body” geometry with atomically sharp and structurally robust core/shell interfaces, as they were spontaneously converted from identical metal current collectors via sequential oxidation/sulfurization” according to the research paper.

The new prototype is said to be charged 30,000 times without any draining, 20 times the lifetime of an ordinary battery.

“You could charge your mobile phone in a few seconds and you wouldn’t need to charge it again for over a week,” says UCF postdoctoral associate Nitin Choudhary.

This research was published in the NANO science journal, you can check the scientific paper here.

Bluetooth 5 Is Here!

The Bluetooth Special Interest Group (SIG) has officially launched the core specifications of the new version of Bluetooth: Bluetooth 5. These specifications include longer range, faster speed, and larger broadcast message capacity, as well as improved interoperability and coexistence with other wireless technologies than recent Bluetooth versions, making it possible to advance IoT applications and usages.

Bluetooth is revolutionizing how people experience the IoT. Bluetooth 5 continues to drive this revolution by delivering reliable IoT connections and mobilizing the adoption of beacons, which in turn will decrease connection barriers and enable a seamless IoT experience” says Mark Powell, SIG’s executive director.

Keeping up with powering IoT, Bluetooth 5 has some additional features that better enable industrial automation and whole home coverage by addressing challenges like range and download speeds. It is said to improve location awareness with a smarter technology that collects data to provide personalized experiences for the end user.

While doubling the speed to enable the making of more responsive devices, Bluetooth 5 developers didn’t miss to maintain low-power consumption that results a faster data transfer.

By 2021, ABI Research predicts 48 billion internet-enabled devices will be installed, and Bluetooth—predicted to be in nearly one-third of those devices—is a cornerstone of that growth.

“The global wireless connectivity market is growing rapidly, with an anticipated 10 billion annual IC shipments by 2021,” said Andrew Zignani with ABI Research. “The introduction of Bluetooth 5 will create new opportunities in various verticals of the IoT market by reducing complexity and cost and giving manufacturers greater flexibility in targeting multiple applications and use cases.”

Within two to six months, new products are expected to be launched using this ubiquitous technology, so stay tuned!

More details about Bluetooth 5 here: www.bluetooth.com/bluetooth5

First Solid-State Multi-Ion Sensor for Internet-of-Things Applications By Imec & Holst Centre

At last week’s IEEE International Electron Devices Meeting (IEDM) in San Francisco (USA), imec, the world-leading research and innovation hub in nano-electronics and digital technology and Holst Centre debuted a miniaturized sensor that simultaneously determines pH and chloride (Cl-)levels in fluid. This innovation is a must have for accurate long-term measurement of ion concentrations in applications such as environmental monitoring, precision agriculture and diagnostics for personalized healthcare. The sensor is an industry first and thanks to the SoC (system on chip) integration it enables massive and cost-effective deployments in Internet-of-Things (IoT) settings. Its innovative electrode design results in a similar or better performance compared to today’s standard equipment for measuring single ion concentrations and allows for additional ion tests.

Sensors based on ion-selective membranes are considered the gold standard to measure ion concentrations in many applications, such as water quality, agriculture, and analytical chemistry. They consist of two electrodes, the ion-sensitive electrode with the membrane (ISE) and a reference electrode (RE). When these electrodes are immersed in a fluid, a potential is generated that scales with the logarithm of the ion activity in the fluid, forming a measure for the concentration. However, the precision of the sensor depends on the long-term stability of the miniaturized RE, a challenge that has now been overcome.

“The common issue with such designs is the leaching of ions from the internal electrolyte, causing the sensor to drift over time,” stated Marcel Zevenbergen, senior researcher at imec/Holst Centre. “To suppress such leaching, we designed and fabricated an RE with a microfluidic channel as junction and combined it with solid-state iridium oxide (IrOx) and silver chloride (AgCl) electrodes fabricated on a silicon substrate, respectively as indicating electrodes for pH and Cl-. Our tests demonstrated this to be a long-term stable solution with the sensor showing a sensitivity, accuracy and response time that are equal or better than existing solutions, while at the same time being much smaller and potentially less expensive.”

“We are providing groundbreaking sensing and analytics solutions for the IoT,” stated John Baekelmans, Managing Director of imec in The Netherlands. “This new multi-ion sensor is one in a series that Holst Centre is currently developing with its partners to form the senses of the IoT. For each sensor, the aim is to leapfrog the current performance of the state-of-the-art sensors in a mass-producible, wireless, energy optimized and miniaturized package.”

Source: imec

New Thermoelectric Paint To Convert Heat Into Electricity

Scientists at the Ulsan National Institute of Science and Technology have developed a thermoelectric coating that can be directly painted onto any surface to turn it into thermal generator. This new technique can be used to convert waste heat into electricity from objects of almost any shape.

The team created an inorganic thermoelectric paint that possesses liquid-like properties using Bi2Te3 (bismuth telluride) and Sb2Te3 (antimony telluride) particles. These newly developed materials are both shape-engineerable and geometrically compatible so they can be directly brush-painted on almost any surface.

To test the new materials results, the researchers painted alternate p-type and n-type layers of the thermoelectric semiconductor paint on a metal dome, which generates about 4 mW output power per square centimeter.

Compared with some flexible thermoelectric generators, such as KAIST’s wearable device and Northwestern University’s thermoelectric material, the generated power of UNIST materials is just 10% of others, but the most important advantage is that it can be applied on any surface with just a paintbrush.

“By developing integral thermoelectric modules through painting process, we have overcome limitations of flat thermoelectric modules and are able to collect heat energy more efficiently.” said Professor Son of UNIST. “Thermoelectric generation systems can be developed as whatever types user want and cost from manufacturing systems can also be greatly reduced by conserving materials and simplifying processes.”

The UNIST researchers aim to see their invention as a renewable energy source, which will be possible to convert heat and cold to electricity by simply painting the external surfaces of buildings, on roofs, and on the exterior of cars, and open the way to many other materials and devices easily transferred to many other voltage-generation applications.

Comparison of power generation between the conventional planar-structured TE generator and the painted TE generator on a curved heat source.

“Our thermoelectric material can be applied any heat source regardless of its shape, type and size.” said Professor Son. “It will place itself as a new type of new and renewable energy generating system.”

To know more about the results and other information of this research, read its paper in the journal Nature Communications.

Sources: New Atlas, UNIST

3 MilliWatt-Consumption Data Glasses

Data glasses display information to the eye without interfering with the wearer‘s vision but they run energy down very quickly due to the consumption of electronics while processing video images and data. Researchers at  Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP had developed a new data glass that has low-power consumption. Received using a radio link, the glasses is able to display images to the wearer while his/her hands are free.

These glasses also goes bright even the power is somehow low thanks to the OLEDs embedded to a silicon semiconductor which controls the individual pixels. Plus, they have the ability to perceive light from the environment around not only emit it.

© Photo Fraunhofer FEP

Another reason to high power consumption in data glasses is loading the data stream, but FEP researchers have came up with a new way to reduce it by changing only objects that are changed and keep the constant ones,

“We now control the chip so that the entire video image is not constantly renewed, rather only that part of the display in which something changes.” – Project manager Philipp Wartenberg “For example, if an actor runs through a room in a movie, only his position changes, not the background. In applications such as a navigation system for cyclists, in which only arrows or metre information is displayed, it is unnecessary in any case to constantly renew the whole picture, to put it simply, we have now adapted the circuit so that it only lets through that portion of the data stream which changes.”

FEP data glasses requires an output of 2-3 milliWatts, a fraction of the output need for ordinary displays – around 200 milliWatts.

The new display was presented at the electronica trade fair in Munich on November 08-11, 2016 and its developers hope to see it used by athletes and private clients. You can read more about it at the press release.

Supercapacitors made of 2D Materials Can End Battery Issues

These tiny batteries can be charged in seconds and last for a week

Battery anxiety is a modern day problem for many of us. Mobile phone and wearable technologies are getting developed rapidly, but battery issues seem to be neverending. As phones and wearables are getting thinner, there needs to be a trade-off between battery life and design. Scientists are searching for a way to make a battery that’s tiny yet capable of holding the charge for a long time. So, what’s the solution? Supercapacitor.

Flexible Laser Scribed Graphene Supercapacitor
Flexible Laser Scribed Graphene (LSG) Supercapacitor

Scientists have been researching on the use of nanomaterials to improve supercapacitors that could enhance or even replace batteries in electronic devices. But it’s not an easy task. Considering a typical supercapacitor, it must be a large one to store as much energy as a Li-ion battery holds.

To tackle the battery issue, a team of scientists at the University of Central Florida (UCF) has created a tiny supercapacitor battery applying newly discovered two-dimensional materials with only a few atoms thick layer. Surprisingly, the new process created at UCF yields a supercapacitor that doesn’t degrade even after it’s been recharged/discharged 30,000 times. Where a lithium-ion battery can be recharged less than 1,500 times without significant failure.

So, what else makes the supercapacitor special apart from their tiny size? Well, let’s hear it from Nitin Choudhary, a postdoctoral associate who conducted much of the research :

If they were to replace the batteries with these supercapacitors, you could charge your mobile phone in a few seconds and you wouldn’t need to charge it again for over a week.

Supercapacitors are not used in mobile devices for their large size. But the team at UCF has developed supercapacitors composed of millions of nanometer-thick wires coated with shells of two-dimensional materials. A highly conductive core helps fast electron transfer for fast charging and discharging. And uniformly coated shells of two-dimensional (2D) materials produce high energy and power densities.

Nanowire Supercapacitor Made of Capacitive 2D WS2 Layers
Nanowire Supercapacitor Made of Capacitive 2D WS2 Layers

Scientists already knew 2D materials held great promise for energy storage purpose. But until the UCF developed the process for integrating those materials, it was not possible to realize that potential. Nitin Choudhary said,

For small electronic devices, our materials are surpassing the conventional ones worldwide in terms of energy density, power density, and cyclic stability.

Supercapacitors that use the new materials could be used in phones, wearables, other electronic gadgets, and electric vehicles. Though it’s not ready for commercialization yet. But the research team at UCF hopes this technology will soon end the battery problem of smartphones and other devices. So let’s wait awhile, and at the end of this year maybe you’ll be using a new smartphone that can be charged in seconds and lasts for a week, who knows!

3D Printed Organ-On-Chip

Researcher at Harvard University had been working to build new microphysiological systems (MPS), also known as organs-on-chips, that can mimic the operation of the structure and function of native tissue.

By developing such systems, they are replacing the conventional way of measuring and testing synthetic organs -usually by testing them first on animals.

organonchip

Although such a solution can help in advancing research and making easy organ-replacement real, but it also somehow costly and considered as laborious.

To build up this system you need a clean room and you have to use a complex, multistep lithographic process. To collect data you also need microscopy or high-speed cameras. Considering also the fact that current MPS typically lack integrated sensors, researchers developed six different inks that integrated soft strain sensors within the micro-architecture of the tissue.

09/15/2016 Cambridge, MA. Harvard University. This images shows multi-material, direct write 3D printing of a cardiac microphysiological device. This instrument was designed for in vitro cardiac tissue research. Lori K. Sanders/Harvard University
This images shows multi-material, direct write 3D printing of a cardiac microphysiological device. This instrument was designed for in vitro cardiac tissue research. Lori K. Sanders/Harvard University

They combined all the steps in one automated procedure using 3D printer. The result was  a cardiac microphysiological device — a heart on a chip — with integrated sensors.  According to the research paper, these 6 inks were designed based on “piezo-resistive, high-conductance, and biocompatible soft materials that enable integration of soft strain gauge sensors within micro-architectures that guide the self-assembly of physio-mimetic laminar cardiac tissues”

“We are pushing the boundaries of three-dimensional printing by developing and integrating multiple functional materials within printed devices,” said Jennifer Lewis, Hansjorg Wyss Professor of Biologically Inspired Engineering. “This study is a powerful demonstration of how our platform can be used to create fully functional, instrumented chips for drug screening and disease modeling.”

You can check this video to see this heart in action, and to take a look at the 6 inks 3D printer

Right now, researchers are testing their new heart-on-chip by performing drug studies and longer-term studies of gradual changes in the contractile stress of engineered cardiac tissues, which can take multiple weeks. This approach will make it much easier to test and measure the tissue contractile and its response to various chemicals like drugs and toxins.

This work was published in Nature Materials and the research was named “Instrumented cardiac microphysiological devices via multimaterial three-dimensional printing”.It was supported by the National Science Foundation, the National Center for Advancing Translational Sciences of the National Institutes of Health, the US Army Research Laboratory and the US Army Research, and the Harvard University Materials Research Science and Engineering Center (MRSEC).  For more information, you can check the paper out here and learn more at Harvard website.