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It looks like a small piece of transparent film with tiny engravings on it, and is flexible enough to be bent into a tube. Yet, this piece of “smart” plastic demonstrates excellent performance in terms of data storage and processing capabilities. This novel invention, developed by researchers from the National University of Singapore (NUS), hails a breakthrough in the flexible electronics revolution, and brings researchers a step closer towards making flexible, wearable electronics a reality in the near future.

Associate Professor Yang Hyunsoo from the National University of Singapore, who led a research team to successfully embed a powerful magnetic memory chip on a plastic material, demonstrating the flexibility of the memory chip. Credit: National University of Singapore

Associate Professor Yang Hyunsoo from the National University of Singapore, who led a research team to successfully embed a powerful magnetic memory chip on a plastic material, demonstrating the flexibility of the memory chip. Credit: National University of Singapore

The technological advancement is achieved in collaboration with researchers from Yonsei University, Ghent University and Singapore’s Institute of Materials Research and Engineering. The research team has successfully embedded a powerful magnetic memory chip on a flexible plastic material, and this malleable memory chip will be a critical component for the design and development of flexible and lightweight devices. Such devices have great potential in applications such as automotive, healthcare electronics, industrial motor control and robotics, industrial power and energy management, as well as military and avionics systems.

The research team, led by Associate Professor Yang Hyunsoo of the Department of Electrical and Computer Engineering at the NUS Faculty of Engineering, published their findings in the journal Advanced Materials on 6 July 2016.

Flexible, high-performance memory devices a key enabler for flexible electronics 

Flexible electronics has become the subject of active research in recent times. In particular, flexible magnetic memory devices have attracted a lot of attention as they are the fundamental component required for data storage and processing in wearable electronics and biomedical devices, which require various functions such as wireless communication, information storage and code processing.

Although a substantial amount of research has been conducted on different types of memory chips and materials, there are still significant challenges in fabricating high performance memory chips on soft substrates that are flexible, without sacrificing performance.

To address the current technological challenges, the research team, led by Assoc Prof Yang, developed a novel technique to implant a high-performance magnetic memory chip on a flexible plastic surface.

The novel device operates on magnetoresistive random access memory (MRAM), which uses a magnesium oxide (MgO)-based magnetic tunnel junction (MTJ) to store data. MRAM outperforms conventional random access memory (RAM) computer chips in many aspects, including the ability to retain data after a power supply is cut off, high processing speed, and low power consumption.

Novel technique to implant MRAM chip on a flexible plastic surface

The research team first grew the MgO-based MTJ on a silicon surface, and then etched away the underlying silicon. Using a transfer printing approach, the team implanted the magnetic memory chip on a ?exible plastic surface made of polyethylene terephthalate while controlling the amount of strain caused by placing the memory chip on the plastic surface.

Assoc Prof Yang said, “Our experiments showed that our device’s tunneling magnetoresistance could reach up to 300 per cent – it’s like a car having extraordinary levels of horsepower. We have also managed to achieve improved abruptness of switching. With all these enhanced features, the flexible magnetic chip is able to transfer data faster.”

Commenting on the significance of the breakthrough, Assoc Prof Yang said, “Flexible electronics will become the norm in the near future, and all new electronic components should be compatible with flexible electronics. We are the first team to fabricate magnetic memory on a flexible surface, and this significant milestone gives us the impetus to further enhance the performance of flexible memory devices and contribute towards the flexible electronics revolution.”

Assoc Prof Yang and his team were recently granted United States and South Korea patents for their technology. They are conducting experiments to improve the magnetoresistance of the device by fine-tuning the level of strain in its magnetic structure, and they are also planning to apply their technique in various other electronic components. The team is also interested to work with industry partners to explore further applications of this novel technology.

STMicroelectronics has introduced a new line up of world’s smallest single-chip motor drivers for the portable and wearable applications. With the combination of low power consumption and small form factor, the ST’s new motor driver plans to contribute to the battery powered IoT device adoption.

The 3mm by 3mm motor drivers will focus on combining logic and power components in a single chip while taking care of power budgets and tight space. The drivers will operate from a supply voltage of 1.8V with the standby current of less than 80nA for a zero-power state. The drivers can also be used in a wide range of applications including robotic positioning systems, printer motors, camera-autofocus mechanisms, toothbrush motors or syringe pumps.

The existence of portable devices in everyday life is becoming more significant with the considerable increase in the use of well-developed battery-powered equipment with extended run-time that becomes smaller day by day.

“Our latest STSPIN single-chip devices are proven to simplify precision motor control and cut time to market for new products,” said Domenico Arrigo, General Manager Industrial and Power Conversion Division, STMicroelectronics. “The ultra-low power consumption extends runtime in battery-operated applications and enables designers to enhance portable and mobile devices with high-added-value motorized functions.”

ST’s new STSPIN motor devices are in production and are priced from $0.75 and $0.96 for order of 1,000 pieces.

EV Group (EVG), a supplier of wafer bonding and lithography equipment for the MEMS, nanotechnology and semiconductor markets, today introduced new capabilities on the EVG ComBond automated high-vacuum wafer bonding platform specifically designed to support high-volume manufacturing (HVM) of advanced MEMS devices. These capabilities include a new vacuum bond alignment module that provides sub-micron face-to-face alignment accuracy essential for wafer-level MEMS packaging, and a new bake module that performs critical process steps to achieve outstanding bond quality and performance of encapsulated MEMS devices.

The addition of these two new modules–coupled with existing capabilities on the highly configurable EVG ComBond platform such as room-temperature covalent bonding of engineered substrates–enables customers to meet the wafer bonding requirements for both current and emerging types of MEMS devices. Examples include gyroscopes, microbolometers, and advanced sensors for autonomous cars, virtual reality headsets and other applications.

“When EV Group introduced the EVG ComBond platform, we set a new standard in high-vacuum wafer bonding by building the product around a modular, highly customizable cluster design concept. This has enabled us to continually expand the capabilities of the platform over time, with applications ranging from advanced engineered substrates, power devices and solar cells to high-performance logic and ‘Beyond CMOS’ devices,” stated Paul Lindner, executive technology director,
EV Group. “With the addition of new vacuum alignment and bake modules, those wafer bonding capabilities have been expanded yet again to address the volume manufacturing needs for high-end MEMS devices.”

Challenges of scaling MEMS wafer bonding into production

Many MEMS devices have extremely small moving parts, which must be protected from the external environment. Wafer-level capping can seal a wafer’s worth of MEMS devices in one operation, and these capped devices can then be packaged into much simpler and lower-cost packages. Metal-based aligned wafer bonding is the preferred approach to MEMS wafer bonding, but is challenging to implement due to the high process temperatures involved as well as the presence of oxides that form on the bonding metal layers. As MEMS die and feature sizes decrease, achieving tighter wafer alignment accuracy also becomes increasingly important.

At the same time, vacuum encapsulation is increasingly needed for certain MEMS devices in order to reduce power consumption caused by parasitic drag, reduce convection heat transfer, or prevent oxide corrosion. Maintaining the required vacuum level for the entire wafer bonding process has been a key challenge for ramping these devices into high-volume production.

The EVG ComBond platform provides a complete end-to-end high-vacuum environment (10-8 mbar range) throughout all wafer handling, pre-bonding and bonding processes. This modular configuration significantly improves serviceability, as modules can be swapped out without breaking the vacuum level within the cluster or modules and interrupting tool operation.

New MEMS wafer bonding capabilities

New to the EVG ComBond platform is the vacuum alignment module (VAM) with wafer clamping, which enables sub-micron face-to-face alignment accuracy based on EVG’s proprietary SmartView alignment process, as well as backside and IR alignment, in a high-vacuum environment. Also new is the programmable dehydration bake and getter activation module, which accelerates the removal of sticking gas molecules prior to bonding the substrates–resulting in improved bond quality as well as reduced gas pressure in device cavities.

In addition, the EVG ComBond platform features an optional ComBond Activation Module (CAM), which enables covalent and oxide-free wafer bonding processes at room temperature or low temperatures. Integrated into the ComBond platform, the CAM allows low-temperature bonding of metals, such as aluminum, that re-oxidize quickly in ambient environments–enabling customers to reduce production costs and achieve higher wafer-bonding throughputs.

The EVG ComBond platform with the new alignment and programmable dehydration bake and getter activation modules is currently available and can be demonstrated at EVG’s headquarters.

Media, analysts and potential customers interested in learning more about EVG’s suite of wafer bonding solutions, including the EVG ComBond platform, are invited to visit the company’s booth #1017 in the South Hall of the Moscone Convention Center in San Francisco, Calif., at the SEMICON West show on July 12-14.

Scientists and doctors in recent decades have made vast leaps in the treatment of cardiac problems – particularly with the development in recent years of so-called “cardiac patches,” swaths of engineered heart tissue that can replace heart muscle damaged during a heart attack.

Thanks to the work of Charles Lieber and others, the next leap may be in sight.

The Mark Hyman, Jr. Professor of Chemistry and Chair of the Department of Chemistry and Chemical Biology, Lieber, postdoctoral fellow Xiaochuan Dai and other co-authors of a study that describes the construction of nanoscale electronic scaffolds that can be seeded with cardiac cells to produce a “bionic” cardiac patch. The study is described in a June 27 paper published in Nature Nanotechnology.

“I think one of the biggest impacts would ultimately be in the area that involves replaced of damaged cardiac tissue with pre-formed tissue patches,” Lieber said. “Rather than simply implanting an engineered patch built on a passive scaffold, our works suggests it will be possible to surgically implant an innervated patch that would now be able to monitor and subtly adjust its performance.”

Once implanted, Lieber said, the bionic patch could act similarly to a pacemaker – delivering electrical shocks to correct arrhythmia, but the possibilities don’t end there.

“In this study, we’ve shown we can change the frequency and direction of signal propagation,” he continued. “We believe it could be very important for controlling arrhythmia and other cardiac conditions.”

Unlike traditional pacemakers, Lieber said, the bionic patch – because its electronic components are integrated throughout the tissue – can detect arrhythmia far sooner, and operate at far lower voltages.

“Even before a person started to go into large-scale arrhythmia that frequently causes irreversible damage or other heart problems, this could detect the early-stage instabilities and intervene sooner,” he said. “It can also continuously monitor the feedback from the tissue and actively respond.”

“And a normal pacemaker, because it’s on the surface, has to use relatively high voltages,” Lieber added.

The patch might also find use, Lieber said, as a tool to monitor the responses under cardiac drugs, or to help pharmaceutical companies to screen the effectiveness of drugs under development.

Likewise, the bionic cardiac patch can also be a unique platform, he further mentioned, to study the tissue behavior evolving during some developmental processes, such as aging, ischemia or differentiation of stem cells into mature cardiac cells.

Although the bionic cardiac patch has not yet been implanted in animals, “we are interested in identifying collaborators already investigating cardiac patch implantation to treat myocardial infarction in a rodent model,” he said. “I don’t think it would be difficult to build this into a simpler, easily implantable system.”

In the long term, Lieber believes, the development of nanoscale tissue scaffolds represents a new paradigm for integrating biology with electronics in a virtually seamless way.

Using the injectable electronics technology he pioneered last year, Lieber even suggested that similar cardiac patches might one day simply be delivered by injection.

“It may actually be that, in the future, this won’t be done with a surgical patch,” he said. “We could simply do a co-injection of cells with the mesh, and it assembles itself inside the body, so it’s less invasive.”

VTT Technical Research Centre of Finland developed an extremely efficient small-size energy storage, a micro-supercapacitor, which can be integrated directly inside a silicon microcircuit chip. The high energy and power density of the miniaturized energy storage relies on the new hybrid nanomaterial developed recently at VTT. This technology opens new possibilities for integrated mobile devices and paves the way for zero-power autonomous devices required for the future Internet of Things (IoT).

Supercapacitors resemble electrochemical batteries. However, in contrast to for example mobile phone lithium ion batteries, which utilize chemical reactions to store energy, supercapacitors store mainly electrostatic energy that is bound at the interface between liquid and solid electrodes. Similarly to batteries supercapacitors are typically discrete devices with large variety of use cases from small electronic gadgets to the large energy storages of electrical vehicles.

The energy and power density of a supercapacitor depends on the surface area and conductivity of the solid electrodes. VTT’s research group has developed a hybrid nanomaterial electrode, which consists of porous silicon coated with a few nanometre thick titanium nitride layer by atomic layer deposition (ALD). This approach leads to a record large conductive surface in a small volume. Inclusion of ionic liquid in a micro channel formed in between two hybrid electrodes results in extremely small and efficient energy storage.

The new supercapacitor has excellent performance. For the first time, silicon based micro-supercapacitor competes with the leading carbon and graphene based devices in power, energy and durability.

Micro-supercapacitors can be integrated directly with active microelectronic devices to store electrical energy generated by different thermal, light and vibration energy harvesters and to supply the electrical energy when needed. This is important for autonomous sensor networks, wearable electronics and mobile electronics of the IoT.

VTT’s research group takes the integration to the extreme by integrating the new nanomaterial micro-supercapacitor energy storage directly inside a silicon chip. The demonstrated in-chip supercapacitor technology enables storing energy of as much as 0.2 joule and impressive power generation of 2 watts on a one square centimetre silicon chip. At the same time it leaves the surface of the chip available for active integrated microcircuits and sensors.

VTT is currently seeking a party interested in commercializing the technique.

At this week’s Design Automation Conference (DAC 2016), nanoelectronics research center imec, Holst Centre (initiated by imec and TNO), and Wi-Fi IP provider Methods2Bussiness will present a complete Wi-Fi HaLow radio solution. The new low-power, long-range radio solution uses 10 times less power than state-of-the-art orthogonal frequency division multiplexing (OFDM) radio solutions on the market. It can be used for a broad range of applications related to the Internet of Things (IoT) and complies with the most recent wireless networking protocol, IEEE 802.11ah.

The radio solution’s compliance with the recently amended wireless networking protocol ensures that it is especially optimized for IoT-related applications. The Wi-Fi Alliance recently introduced the HaLow (TM) designation for the new low-power, long-range Wi-Fi protocol IEEE802.11ah. Compared to other IoT standards, its sub-GHz carrier frequency and mandatory modes with 1MHz/2MHz channel bandwidths allow devices to operate over a longer range with scalable data rates from 150kb/s to 7.8Mb/s. The standard uses OFDM to improve the link robustness against fading, which is important in urban environments, and to achieve a high spectral efficiency (data rate over a given bandwidth).

The radio integrates imec and Holst Centre’s sub-1GHz IEEE 802.11ah transceiver and Methods2Business’ Medium Access Controller (MAC) hardware and software IP and application layer to enable 802.11ah communication between large numbers of IoT clients and the internet using a central access point. The transceiver comprises a complete low-power physical layer implementation of RF front-end and digital baseband. It features a 1.3nJ/b fully digital polar transmitter optimized for IoT applications as well as for the novel IEEE 802.11ah Wi-Fi protocol. The transmitter surpasses the tight spectral mask and error-vector-magnitude (EVM) requirements of conventional Wi-Fi standards. It does so while demonstrating a power consumption rate as low as 7.1mW in Tx mode for 0dBm output power.

Methods2Business 802.11ah MAC core implements all the new Wi-Fi HaLow functionality to address the drawbacks of traditional Wi-Fi in IoT. Besides mandatory features for connecting up to 8.000 IoT clients (Hierarchical AID), improving collision avoidance in channel access mechanisms (CSMA/CA, DCF, EDCA), and increasing throughput by supporting shorter MAC headers, very advanced power saving modes like Target Wake Time (TWT) and Restricted Access Window (RAW) are also supported. To further trade-off power versus performance, time-critical functions are implemented in hardware while higher level MAC protocols are realized in software.

Imec’s connectivity research for the intuitive internet of things focuses on the development of ultra-small, low-cost, intelligent, and ultra–low power sensors, radio chips and heterogeneous sensor networks. Imec’s Intuitive IoT R&D program focuses on developing the building blocks for future IoT-related applications, with intuitive technology where sensor systems are aware of humans, human perspectives, and human’s environment. This intuitive IoT technology can react exactly as humans need or want them to, providing assistance in an unobtrusive way. Interested companies are invited to join imec’s research efforts as research partners or they can have access to imec’s innovative technology through licensing programs for further development.

By Dr. Khasha Ghaffarzadeh, Research Director, IDTechEx

The first generation of wearable devices are constructed using mature, rigid technologies put inside a new box that can be worn. These are often bulky devices that are not truly wearable in the sense that our clothes are. This is, however, beginning to change, albeit slowly. New conformal, clothing-based components are emerging. Further announcements last week from Google’s Project Jacquard, in collaboration with Levis, shows that the technology and fashion industries are starting to make real progress through collaboration.

This project is but one example of work being done and the IDTechEx Research report, E-Textiles 2016-2026: Technologies, Markets, and Players, finds that electronic textiles (e-textiles) are on the cusp of rapid growth, forecasting the market to increase from under $150m in 2016 to over $3.2bn by 2026.  Many still argue that e-textiles are solutions looking for a problem, but IDTechEx Research finds that there is tremendous interest and progress right across the value chain. This includes material suppliers, traditional textile companies, contract manufacturers, brand owners, etc.

Conductors will inevitably play an indispensable role in any e-textile system. Naturally, therefore, conductive inks suppliers are all very interested. In parallel, conductive ink suppliers face challenging conditions in their traditional well-established market sectors.

For example, IDTechEx Research report, Conductive Ink Markets 2016-2026: Forecasts, Technologies, and Players, forecasts that the combined market for the previously well-established photovoltaic and touch screen edge electrodes will achieve a measly CAGR of 1-2% between 2016 and 2026.  The latter segment is forecast to decline whilst growth in the former will be hugely constrained thanks to the decreasing average silver consumption per cell.

In fact, these traditional markets are increasingly characterised by low demand growth, intense competition, high customer price sensitivity, and low customer loyalty.  This is yet another reason why conductive inks suppliers are hugely interested in new high-growth applications areas such as e-textiles.

Source: IDTechEx Research

Source: IDTechEx Research

Conductive inks win on their universality?

Conductive ink suppliers are touching and feeling their way into the e-textile market. Many have launched specially-designed inks on the market. Some examples are shown below. Most are also having to proactively help form and develop the nascent value chain. This is currently still more of a push than a pull market.

conductive inks

This is a complex space since conductive inks are one of many approaches being concurrently developed for e-textiles. To name a few, these approaches include metal cabling, textile cabling, conducting knits, conductive wovens, conductive inks, etc. There is a paucity of verified technical information and well-defined figures-of-merit on the market. We have therefore developed our semi-qualitative benchmarking based on many end users and supplier discussions, which can be found within the IDTechEx report: E-Textiles 2016-2026: Technologies, Markets, and Players.

There is no clear-cut winner. This is because some approaches win, say, on ease of integration with existing processes or maturity,whereas others win on increased clothing-like appearance and feel. Project Jacquard’s smart jacket, built specifically for urban bikers, is an excellent example of a compromise in these areas, with the look and feel being key in the selection of conductive yarns as the primary material. Still, there is no one-size-fits-all solution and the winner will be specific to an end use and/or a production process.

This makes sense as the traditional textile world itself includes many fabric types, production processes, and end uses. Despite the appearance of familiarly, this is an incredibly diverse and complex industry.  The technology composition will therefore be a mixed bag in the medium-term as e-textile manufacturers will likely select their conductor of choice based on the specific requirements of each application and their own existing production processes.

In the long-term, e-textile conductive inks will have a larger addressable market than all the other solutions. This is because they offer the highest degree of universal applicability: their integration is a post-production process that can be used by almost any textile manufacturer unless the fabrics cannot withstand high laminating temperatures or are very loose.

In the short to medium term, the risk however is that some end applications are more equal than others. For example, IDTechEx Research finds that smart sports clothing alone will make up 65% of the market by 2020. The challenge is therefore in identifying, targeting and winning in specific high-growth application sectors. IDTechEx Research can help you find and penetrate these sectors.

For more information please refer IDTechEx Research report, Conductive Ink Markets 2016-2026: Forecasts, Technologies, and Players.

Not the finished article yet

The ink technology however is not yet finished article. Achieving washability, direct-on-fabric printability, and high stretchability are challenging technical requirements. The industry is only beginning to accumulate expertise here. Therefore, this is the beginning of the beginning and we expect better e-textile conductive inks in the future.

The process currently is too complicated because the inks need to be printed and cured on a substrate such as TPU before being encapsulated using a similar substrate. The film then needs to be hot laminated over the fabric. This approach improves washability and durability, and does away with the technical headache of having to develop a different ink optimised for each fabric substrate, but screams out to be simplified.

TPU itself is the first choice of encapsulate but not likely to be the last. This is because it is not the most stretchable thus restricting the clothing-like feeling of e-textiles particularly if large areas are covered. Already companies are experimenting with othermaterial systems such as TPU/silicone combinations.

Silver costs can also be a limiting factor. This opens the way for carbon or graphene based inks in applications where high conductivity is not required. In the long term copper inks may also be an option but they have a long way to go to prove their reliability and technology maturity.

Silicon-carbide (SiC) power electronics from STMicroelectronics has enabled the creation of ZapCharger Portable, the world’s smallest, smartest, and safest electric-car charging station from Zaptec, an innovative start-up company that has revolutionized the transformer industry.

The market-first portable electric-car charger with built-in electronic transformer, ZapCharger works with any electric car on any grid. Excellent power-conversion capabilities of ST’s SiC MOSFET devices have enabled Zaptec engineers to design a portable, yet powerful piece of equipment. Ten times smaller and lighter than products with the comparable performance, the 3kg, 45 x 10 x 10cm charger delivers an energy efficiency of 97%.

Uncompromising on safety, the water- and weather-proof ZapCharger is fully galvanically insulated and continuously monitors the grid it is connected to. It dynamically adjusts the amount of power it delivers and can shut down immediately if it detects a fault, to protect the car. The charger offers GPRS connectivity and operates over an extended temperature range from -40 degrees C to +55 degrees C.

Inside the ZapCharger, 32 high-voltage SiC Power MOSFETs from ST deliver efficient power conversion with minimum losses. Compared with traditional (silicon) solutions, these components can sustain much higher voltages, currents, and temperatures, and their power-conversion circuits operate faster, enabling smaller, lighter designs, higher system efficiency, and reduced cooling requirements.

“The key for us was to find a power technology with a very high efficiency so we could reduce the overall size of the charger without compromising performance. ST’s silicon-carbide offering was the perfect match,” said Jonas Helmikstol, COO, Zaptec. “The support of ST as a strong and reliable partner helped us transform our invention into a product that dramatically changes the user experience and by allowing consumers to take their chargers anywhere eliminates ‘range anxiety” and can accelerate the adoption of electric vehicles worldwide.”

“Leveraging the exceptional efficiency of ST SiC Power MOSFETs, ingenious solutions like ZapCharger that can enable drivers to safely charge their vehicles anywhere are set to catalyze the growth of the e-car market and the smart-energy ecosystem as a whole,” said Philip Lolies, EMEA Vice President, Marketing & Application, STMicroelectronics. “Zaptec’s decision to rely on our advanced power technology confirms ST’s industry leadership and enabling role in the global trend towards Greener and Smarter Living.”

In addition to electric-car charging, Zaptec’s patented, prize-awarded electronic-transformer technology targets new applications in Industrial, Marine, and Space.

After successful field tests, ZapCharger is starting pilot production now, with volume ramp-up scheduled at the end of Q3 2016.

MACOM Technology Solutions reported the newest entries in its MAGb series of GaN on Silicon power transistors for use in macro wireless basestations.

According to a media release, based on MACOM’s Gen4 GaN technology, the new MAGb-101822-240B0P and MAGb-101822-120B0P power transistors harness the clear performance benefits of GaN in rugged, low-cost plastic packaging, enabling improved cost efficiencies that further distinguish MACOM’s GaN power transistors as the natural successors to legacy LDMOS offerings for basestation applications.

The Company noted that the new plastic TO-272-packaged MAGb-101822-240B0P and MAGb-101822-120B0P power transistors provide 320 W and 160 W output peak power, respectively, in the load-pull system with fundamental tuning only, and cover all cellular bands and power levels within the 1.8 – 2.2 GHz frequency range. These transistors’ ability to operate over 400 MHz of bandwidth precludes the need to use multiple LDMOS-based products, further optimizing cost and design efficiencies.

MACOM said that plastic-packaged MAGb power transistors deliver power efficiency up to 79 percent – an improvement of up to 10 percent compared to LDMOS offerings – with only fundamental tuning across the 400 MHz RF bandwidth, and with linear gain of up to 20 dB. These transistors provide an alternative to ceramic-packaged devices without compromising RF performance or reliability – thermal behavior is improved by 10 percent compared to ceramic-packaged MAGb offerings.

“DPD is critical to increase the efficiency of power amplifiers for 4G and 5G basestation applications and has a significant impact on network operators’ operating expenses and capital expenditures,” said Dr. Chris Dick, Chief DSP Architect at Xilinx. “Our joint demonstration with MACOM at IMS 2016 will showcase the combined DPD capabilities of MACOM’s Gen4 GaN-based MAGb power transistors and Xilinx’s complementary DPD technologies on our 28 nm Zynq SoC and 16 nm UltraScale+ MPSoCs. This joint solution highlights the time-to-market advantages that can be achieved with a proven, interoperable DPD solution.”

“Our collaboration with Xilinx demonstrates the linearity and ease of correction of our MAGb, especially with signals that are known to be challenging to correct using GaN-based solutions like multi-carrier GSM and TDD-LTE signals,” said Preet Virk, Senior Vice President and General Manager, Carrier Networks, at MACOM. “We believe that with the introduction of our new plastic-packaged MAGb power transistors, we’re further extending this price/performance advantage over competiting LDMOS and other GaN technologies, and accelerating the evolution to GaN-based PAs for wireless basestations.”

The detection of carbon monoxide (CO) in the air is a vital issue, as CO is a poisonous gas and an environmental pollutant. CO typically derives from the incomplete combustion of carbon-based fuels, such as cooking gas and gasoline; it has no odor, taste, or colour and hence it is difficult to detect. Scientists have been investigating sensors that can determine CO concentration, and a team from the Okinawa Institute of Science and Technology Graduate University (OIST), in tandem with the University of Toulouse, has found an innovative method to build such sensors.

As a tool for CO detection, scientists use extremely small wires: copper oxide nanowires. Copper oxide nanowires chemically react with CO, creating an electrical signal that can be used to quantify CO concentration. These nanowires are so thin that it is possible to fit more than 1.000 of them in the average thickness of a human hair.

This is an adaptation of a scanning electron microscopy image of copper oxide nanowires bridging the gap between neighbouring copper microstructures. Credit: OIST

This is an adaptation of a scanning electron microscopy image of copper oxide nanowires bridging the gap between neighbouring copper microstructures. Credit: OIST

Two issues have hampered the use of nanowires. “The first problem is the integration of nanowires into devices that are big enough to be handled and that can also be easily mass produced,” said Prof Mukhles Sowwan, director of the Nanoparticles by Design Unit at OIST. “The second issue is the ability to control the number and position of nanowires in such devices.” Both these difficulties might have been solved by Dr Stephan Steinhauer, postdoctoral scholar at OIST, together with Prof Sowwan, and researchers from the University of Toulouse. They recently published their research in the journal ACS Sensors.

“To create copper oxide nanowires, you need to heat neighbouring copper microstructures. Starting from the microstructures, the nanowires grow and bridge the gap between the microstructures, forming an electrical connection between them,” Dr Steinhauer explained. “We integrated copper microstructures on a micro-hotplate, developed by the University of Toulouse. A micro-hotplate is a thin membrane that can heat up to several hundred Celsius degrees, but with very low power consumption.” Thanks to the micro-hotplate, researchers have a high degree of control over the quantity and position of the nanowires. Also, the micro-hotplate provides scientists with data on the electrical signal that goes through the nanowires.

The final result is an exceptionally sensitive device, capable of detecting very low concentrations of CO. “Potentially, miniaturized CO sensors that integrate copper oxide nanowires with micro-hotplates are the first step towards the next generation of gas sensors,” Prof Sowwan commented. “In contrast to other techniques, our approach is cost effective and suitable for mass production.”

This new method could also help scientists in better understanding the sensor lifetime. The performance of a sensor decreases overtime, and this is a major issue in gas sensing. Data obtained with this method could help scientists in understanding the mechanisms behind such phenomenon, providing them with information that starts at the very beginning of the sensor lifetime. Traditionally, researchers first grow the nanowires, then connect the nanowires to a device, and finally start measuring the CO concentration. “Our method allows to grow the nanowires in a controlled atmosphere, where you can immediately perform gas sensing measurements,” Dr Steinhauer noted. “Basically, you stop growing and start measuring, all in the same location.”