The Kynix Blog

SummaryA metamaterial developed by researchers at King's College London uses quantum effects to turn electrons flowing through a circuit into "hot electrons" and light in a highly controlled manner.According to the team,this has potential application in optoelectronics and sensing. BodyThe nanomaterial takes advantage of electron tunnelling to produce streams of particles which can have important applications, when properly controlled.   Accodring to the researcher Dr Pan Wang,this one tiny device offers several amazing applications: plasmon excitation, light generation and chemical reaction activation. And all this is achieved by a small, easy to produce material which only requires a small voltage to function. A voltage applied across the device causes electrons to flow from one material (eutectic gallium indium) to another (gold nanorods). These are separated by an air gap, which would usually stop the electron flow, but because the air gap is less than 1nm, the electrons can ‘tunnel’ through.Most of the tunnelling electrons arrive at the gold nanorod tips in the form of ‘hot electrons’, but a small proportion excite plasmons in the metamaterial to emit light whose wavelength is directly related to the applied voltage. According to the team, this conversion is usually inefficient, but the use of array gold nanorods provides 100billion tunnel junctions, improving electron-to-plasmon conversion and making the emitted light visible. While there are applications in sensing, the researchers point to a benefit in small scale electronics. Since light is generated by applying a voltage along a 10nm thick nanorod, it can be used to transmit information optically between or within chips. The metamaterial allows optical signals to be produced within a much smaller device, holding the potential of faster electronics. "We expected to generate some weak light which we thought should be enough for various nanophotonic applications when we began these studies," added King’s College Professor Anatoly Zayats ,"but But as sometimes happens in the research, the applications are much richer.” 

SummaryThe process that makes gold-plated jewelry or chrome car accents is now making powerful lithium-ion batteries. It's reported in the Joural Science Advances that research at the University of Illinois, Xerion Advanced Battery Corporation and Nanjing University in China developed a method for electroplating lithium-ion battery cathodes, yielding high-quality, high-performance battery materials that could also open the door to flexible and solid-state batteries in May,2017. Paul V. Braun, a professor of materials science and engineering and director of the Frederick Seitz Materials Research Lab at Illinois said that it's an entirely new approach to manufacturing battery cathodes, which resulted in batteries with previously unobtainable forms and functionalities. Traditional Lithium-ion BatteryTraditional lithium-ion battery cathodes use lithium-containing powders formed at high temperatures. The powder is mixed with gluelike binders and other additives into a slurry, which is spread on a thin sheet of aluminum foil and dried. The slurry layer needs to be thin, so the batteries are limited in how much energy they can store. The glue also limits performance. "The glue is not active. It doesn't contribute anything to the battery, and it gets in the way of electricity flowing in the battery," said co-author Hailong Ning, the director of research and development at Xerion Advanced Battery Corporation in Champaign, a startup company co-founded by Braun. The researchers bypassed the powder and glue process altogether by directly electroplating the lithium materials onto the aluminum foil claimed "You have all this inactive material taking up space inside the battery, while the whole world is trying to get more energy and power from the battery". The Electroplated CathodeSince the electroplated cathode doesn't have any glue taking up space, it packs in 30% more energy than a conventional cathode, according to the paper. It can charge and discharge faster as well, since the current can pass directly through it and not have to navigate around the inactive glue or through the slurry's porous structure. It also has the advantage of being more stable. What's more, the electroplating process creates pure cathode materials, even from impure starting ingredients. This means that manufacturers can use materials lower in cost and quality and the end product will still be high in performance, eliminating the need to start with expensive materials already brought up to battery grade, Braun said.  "This method opens the door to flexible and three-dimensional battery cathodes, since electroplating involves dipping the substrate in a liquid bath to coat it," said co-author Huigang Zhang, a former senior scientist at Xerion who is now a professor at Nanjing University. The researchers demonstrated the technique on carbon foam, a lightweight, inexpensive material, making cathodes that were much thicker than conventional slurries. They also demonstrated it on foils and surfaces with different textures, shapes and flexibility.These designs are impossible to achieve by conventional processes,however,what's really important is that it's a high-performance material and that it's nearly solid. By using a solid electrode rather than a porous one, more energy can be stored in a given volume. One of the day, people want batteries to store a lot of energy and peple will make this thought come true. 

SummaryAs the development of socialty,basically a family will own one car even in the development country. In the future over-the-air updates keep them constantly up to date,and thus also secure.  In the future, car owners will be able to enhance their car’s security, intelligence, and performance without getting up from the sofa. In the future, updating their car’s software will be as simple as updating apps on their smartphones today. A swipe of the smartphone will be enough to automatically update vehicle software or to download new functions directly from the cloud – without any need to visit the repair shop.    Situation AnalysisMore electronics, more functions, more software: the car is turning into a smartphone on wheels. Keeping vehicle software up to date is thus becoming increasingly important. New functions can provide extra convenience, even after the vehicle has been bought. Over-the-air software updates will therefore soon be a standard feature.Today’s vehicles feature as many as 100 control units. Even compact cars have between 30 and 50. Their software governs nearly every function in the vehicle. In addition, more and more vehicles are now connected – with the internet, other cars, and the infrastructure. This means a greater risk of weak links in vehicle software, as well as of manipulation. In this context, software updates over the cloud offer a solution that keeps cars constantly up to date, and thus also secure. In addition, the cloud updates mean that ever more functions can be added, with ever greater scope.If the necessary hardware is already installed, a new software function can be tried out and subsequently downloaded. In this way, lane-keeping or park-assist functions can be added, for example. And it is not just drivers that benefit from over-the-air software updates: in 2015, 15 percent of recalls in the automotive industry in the U.S. had to do with software errors. Four years previously, this figure was only 5 percent, according to a U.S. study based on data from the National Highway Traffic Safety Association (NHTSA). For automakers and their customers alike, such repair-shop visits are a huge waste of time and money, and online updates can significantly reduce this.  Over-the-air Software UpdateThe over-the-air software updates work priciple is secure,fast and simple. On the driver's smartphone or the car’s infotainment system, the online security updates are started and any new functions that need to be downloaded are selected. This information is sent to the cloud, which acts like a kind of app store, holding the updates in readiness and starting the process of downloading software to the vehicle. The data can either be downloaded in the background while the car is moving, or overnight when it is parked in its garage. As soon as the vehicle is in a secure condition (once it has parked, for example), the software updates are installed on the appropriate control units, where they are immediately activated. Security and the smooth interaction of automotive electronics, cloud, and software are decisive for an over-the-air update. Data security is ensured by the latest encryption technologies. A complex security architecture with end-to-end encryption protects the data transmission against unauthorized access. At the car-cloud interfaces, secure protocols and filters act like a firewall to ward off any hacking attempts. To ensure that an over-the-air update is not just secure, but also fast and reliable, fast update technologies such as delta and compression mechanisms are used. These accelerate the update process and reduce cost, since the data volume for the transmission remains low. One further security measure is to transmit the updates in sequences. If problems occur, the update process can be stopped and adjusted. Article resources: BoschArticle edited by kynix 

SummaryMemory is one of the most important part for electronics. Computers and Smartphones woludn't be nearly as useful without room for lots of apps,music and videos. Devices tend to store that  information in two ways: through electric fields (think of a flash drive) or through magnetic fields (like a computer’s spinning hard disk). Each method has advantages and disadvantages. However, in the future, our electronics could benefit from the best of each. There are some questions put by Chang-Beom Eom, the Theodore H. Geballe Professor and Harvey D. Spangler Distinguished Professor of Materials Science and Engineering at the University of Wisconsin-Madison. “Can you cross-couple these two different ways to store information? Could we use an electric field to change the magnetic properties? Then you can have a low-power, multifunctional device. We call this a ‘magnetoelectric’ device.” In research published recently in the journal Nature Communications, Eom and his collaborators describe not only their unique process for making a high-quality magnetoelectric material, but exactly how and why it works. Physics graduate student Julian Irwin checks equipment in the lab of materials science and engineering Professor Chang-Beom Eom, where researchers have produced a material that could exhibit the best qualities of both solid-state and spinning disk digital storage. Magnetoeletric materialsMagnetoelectric materials,which have both magnetic and electrical functionalities,or "orders" already exist. Switching one functionality induces a change in the other.“It’s called cross-coupling,” says Eom. “Yet, how they cross-couple is not clearly understood.” Gaining that understanding, he says, requires studying how the magnetic properties change when an electric field is applied. Up to now, this has been difficult due to the complicated structure of most magnetoelectric materials. In the past,people studied magnetoelectric properties using very "complex" materials,or those that lack uniformity.In his approach,Eom simplified not only the research but the material itself. Drawing on Eom's expertise in material growth,he developed a unique process,using atomic "steps" to guide the growth of a homogenous,single-crystal thin film of bismuth ferrite. Atop that, he added cobalt, which is magnetic; on the bottom, he placed an electrode made of strontium ruthenate.  Bismuth Ferrite MaterialThe bismuth ferrite material was important because it made it much easier for Eom to study the fundamental magnetoelectric cross-coupling. Eom found that in their work,because of their single domain,they could actually see what was going on using multiple probing, or imaging, techniques.The mechanism is intrinsic. It’s reproducible — and that means you can make a device without any degradation, in a predictable way. To image the changing  electric and magnetic properties switching in real time, Eom and his colleagues used the powerful synchrotron light sources at Argonne National Laboratory outside Chicago, and in Switzerland and the United Kingdom. “When you switch it, the electrical field switches the electric polarization. If it’s ‘downward,’ it switches ‘upward,'” he says. “The coupling to the magnetic layer then changes its properties: a magnetoelectric storage device.” That change in direction enables researchers to take the next steps needed to add programmable integrated circuits — the building blocks that are the foundation of our electronics — to the material. While the homogenous material enabled Eom to answer important scientific questions about how magnetoelectric cross-coupling happens, it also could enable manufacturers to improve their electronics.Eom saied they can design a much more effective,efficient and low-power device now. 

SummaryRS-485 has been an industrial workhorse because of its robustness and reliability.  Initially used as a communication network in laboratory instrumentation, RS-485 can be found in applications ranging from building automation to traffic monitoring systems. As the use of RS-485 grew, demand increased for a higher output voltage swing, a wider common-mode range and increased tolerance to electrostatic discharges. There was also a need for greater stand-off capability or protection against persistent over-voltages beyond the maximum transceiver supply level specified in datasheets.  OVP Versus Transient Protection  As the above picture shows,the 24V and 48V DC supplies in industrial and telecom systems are commonly distributed through the same conduits as the data lines of an RS-485 network,there can be multiple causes for over-voltage faults when data lines share the same conduits as DC power lines. On the one hand,if a DC supply shares the same connector or screw terminal block with the data lines of an adjacent bus node circuit,wiring faults can occur that connect one or more supply conductors with the transceiver bus terminals. Another cause of failures is the layouto of the conduit. Sharp bends often violate the minimum cable radius specified for data and supply cables. Over time, the increased mechanical pressure on the cable will cause a break in the insulation, causing shorts between power and data lines. This can also happen when machinery or equipment is placed against a conduit, thus crunching the cable. Over-voltage events can last for minutes and even up to weeks until their causes are eliminated. Much shorter over-voltage events, such as over-voltage transients, can occur due to load switching activity in the power distribution system and lightning strikes, which induce high surge currents and voltages into the data lines. Engineers new to over-voltage protection often assume that protection against short- and long-term over-voltages can be provided by adding external transient voltage suppressors (TVS) to a non-fault protected, standard transceiver. This is not true because the maximum power which the TVS can absorb decreases with increasing transient duration. The following image shows a 600W TVS rated at 1ms pulse width. Note that the time axis ranges from 10μs to 10ms, with power levels of 6kW and 200W respectively. From this characteristic, it should be clear that exposing a TVS to long-term over-voltages would fry the device.  Therefore fault protected transceivers are needed to protect bus nodes against a wide range of over-voltages. These transceivers can provide protection against DC over-voltages of up to ±60V and transient over-voltages of up to ±80V.   Integrated Versus DiscreteOccasionally, designers ask ‘why not use a non-fault protected, standard transceiver and a few discrete low-cost transistors with sufficient high voltage breakdown for over-voltage protection?’. The answer is simple: A discrete solution adds more cost and development time and consumes more space than a fault-protected transceiver. Let's assume the function of the fault-protected, half-duplex transceiver in the following picture is to be accomplished with a discrete design using a standard transceiver. First, the transmit path and the receive path must be separate to allow for the implementation of a boosted output stage with high standoff voltage. This requires the use of a full duplex transceiver. The output stage could be realised with four discrete transistors or an integrated H-bridge, whose control inputs require the conversion of RS-485 bus signals into TTL or CMOS logic levels. This would require a drive logic circuit between the transceiver and the discrete output stage. In the receive path, a discrete voltage limiter, consisting of Zener diodes and series resistors, must be implemented to limit the bus voltage during an over-voltage event, otherwise it remains transparent. The following picture shows that the discrete solution already becomes cumbersome by merely providing the basic functions for over-voltage protection, while still lacking a current limiter, which is a vital component for over-voltage protection. Current limiting is a critical function during over-voltage events when the driver is actively driving the bus. Because the enabled driver presents a low-impedance connection to ground, bus currents flowing through the driver become huge, damaging the device if they are not limited. Current LimitingFault-protected transceivers with common-mode ranges wider than specified in the RS-485 standard require double fold-back current limiting within the driver stage. Figure 4 shows the current limiting function of the ISL3245x family of fault-protected transceivers that operate over the wide common-mode range of ±20V. Here, the first fold-back current level of 63mA ensures that the driver never folds back when driving loads within the entire 40V common-mode voltages. The low second fold-back current setting of 13mA minimises power dissipation if the driver is enabled when a fault occurs. This current limiting scheme ensures that the output current never exceeds the RS-485 specification, even at the common mode and fault condition voltage range extremes. In the event of a major short-circuit condition, the transceivers also provide a thermal shutdown function that disables the drivers whenever the die temperature becomes excessive. This eliminates any power dissipation and allows the die to cool. The drivers automatically re-enable after the die temperature drops by 15°C. If the fault condition persists, the thermal shutdown/re-enable cycle repeats until the fault is cleared. Receivers stay operational during thermal shutdown and fault-protection is active, regardless of whether the driver is enabled, disabled or the IC is powered down.The energy of over-voltage transients caused by lightning can easily exceed the transceiver's fault protection and must be absorbed by external TVS diodes. Two conditions need to be satisfied when adding external TVS devices to a fault-protected transceiver: The TVS breakdown voltage must be 1V higher than the highest common-mode voltage of the application or the maximum DC-supply, whichever is higher.The peak clamping voltage of the TVS must be less than the transceiver’s maximum fault-protection levels.Fault-protected transceivers with a wide supply voltage range enable designers to use the same device in 3.3 and 5V systems, which reduces logistics and can lead to an attractive price break for higher volumes. However, not all 3V to 5V transceivers provide sufficient drive capability at low supply and neither do they necessarily operate down to 3V. ClosingSystem designers are no longer required to choose between robust fault tolerance and high performance in RS-485 and RS-422 transceivers; devices such as the ISL32458E and ISL32459E from Intersil offer both. These transceivers feature ±60V over-voltage and ±15kV ESD tolerance, while including operation from supply voltages ranging from 3V to 5.5V. They also operate with data rates of up to 20Mbit/s and provide a ±20V common-mode voltage range. In addition the ISL32459E provides a cable-invert function.  Article resources: Writed by Thomas Kugelstadt,a principal applications engineer with Intersil, a Renesas companyArticle edited by kynix 

SummarySingaporean researchers,led by by professor Hirotaka Sato,describe their work about designing robots--It's possible to use a living insect as a platform to develop a living insect-machine hybrid robot.Such a hybrid retains the complex structure of the insect's rigid exokeleton,complaint joints,and soft actuators, as well as the insect’s locomotion capability, and it does so while enabling high controllability and low power consumption. Such an insect-machine hybrid robot is made of a living insect platform with a miniaturized electronic device attached on it to control it.   By using the insect itself as the robot, researchers bypass the complex processes of designing and fabricating the robot body, using the insect’s muscular system as the soft actuators and flexible joints and its nervous system as part of the control system. About BeetleThis kind of particular beetle is a a darkling beetle. It’s small (2 to 2.5 centimeters), lightweight (about 0.5 gram), and lives for three months or so, which is a long time for a little bug. A backpack of electronics interfaces with the beetle’s antennae, and when the antennae are stimulated with an electric pulse, it activates the beetle’s built-in escape mechanism, fooling it into thinking it’s running into something and causing it to turn. The picture is from Nanyang Technological University AdvantageThe advantage of doing things this way (as opposed to direct nerve or muscle stimulation, something that the researchers also experimented with) is that the beetle’s brain is still in charge of controlling its limbs such that it’ll respond to high-level controls with adaptive gaits and such, making locomotion a much simpler problem to solve. With just two coin cell batteries, the cybeetle can be controlled for 8 hours, which is long enough for it to travel over a kilometer at an average speed of 4 cm/s. The following picture is from  Cyborg Insect: Ultralightweight Living Legged Robot The key to effectively controlling an insect using these methods is that the response to the antenna stimulation can’t be binary, since you’d end up with a level of control that would often be too coarse to be useful. By changing the frequency of the stimulation, the researchers were able to modulate how sharp of a turn the insect took: Increasing the stimulation frequency also increased the insect’s turning rate, with a success rate of over 85 percent. Stimulating both antennae at once causes the insect to back up, and it moves forward by default, giving you just about as much control as you can hope for. Living Robots' DifferencesElectrical stimulation is commonly used for neuromuscular stimulation in cyborg insects such as cockroaches, giant beetles, and moths. There are other groups working on antenna stimulation but they were not able to grade the response of the insect, which is very important for developing a precise closed-loop control system to make the cyborg insect work autonomously. The giant cyborg beetle mainly relies on neuromuscular stimulation of direct flight muscles for flight control and leg muscles of the fore legs for walking control. Ideally, stimulating the muscle would be more precise as we can perfectly control the individual legs, but it costs more in implantation and computing to plan and stimulate all the individual muscles for walking. Antenna stimulation is simpler and easier than stimulating all the individual muscles thus it helps us to simplify the hardware and control system a lot. Hopefully, in the near future, we can control the cyborg beetle as precisely as any other artificial motor. The zophobas beetle were used to develop this cyborg insect because its small size (2-2.5 cm) would help it to access the small rubbles system easily at disaster sites, where the cockroach and giant beetle can not get in. Moreover, a swarming of flying and walking cyborg insects of various sizes would increase the coverage and reduce the searching time, thus enhancing the efficiency and accuracy of search and rescue operations. Control IssueFor walking cyborg insects, researchers are able to integrate external sensors into the backpack as the insect is able to carry loads up to double its weight. We are developing a new backpack with integrated sensors for human detection and navigation. It would help us to detect victims when using cyborg insects at disaster sites, and enable the cyborg insects to work autonomously. On the other hand,research could release hundreds of flying and crawling cyborg insects to the sites as the price for one cyborg insect would be negligible once mass produced for a disaster scenario.The insects can move freely themselves into the collapsed structures and send back maps of their positions and environmental conditions so that the rescue team can plan for their action efficiently on how and where they should access. Once an insect detects a victim, it will send an alarm to the rescue team and switch to autonomous control mode to move around the victim for confirmation and build a clearer map of surrounding environment. At the end of the rescue operation, all the insects will autonomously return to the control base. I know that it sounds like science fiction, but we are in fact working to realize it. Researcher's GoalNow,researchers are working on a feedback control system to precisely control the insect locomotion with high reliability. We are also developing a new backpack with a navigation system and environmental sensors designed to promote fully autonomous and practical cyborg insects. For real applications, we need to maintain the power supply for the cyborg insect (mainly for the electronics backpack), which is currently a huge challenge if we just rely on the battery. So we are developing a biofuel cell, which is able to convert biofuel inside the insect to electric current for running the control backpack. It will help to maintain the backpack power for long-term use. Article resources: journal Soft RoboticsAtticle edited by kynix