The Kynix Blog

Electrical engineers at the University of California San Diego have developed a temperature sensor that runs on only 113 picowatts of power -- 628 times lower power than the state of the art and about 10 billion times smaller than a watt. This near-zero-power temperature sensor could extend the battery life of wearable or implantable devices that monitor body temperature, smart home monitoring systems, Internet of Things devices and environmental monitoring systems.   The technology could also enable a new class of devices that can be powered by harvesting energy from low-power sources, such as the body or the surrounding environment, researchers said. The work was published in Scientific Reports on June 30.   "Our vision is to make wearable devices that are so unobtrusive, so invisible that users are virtually unaware that they're wearing their wearables, making them 'unawearables.' Our new near-zero-power technology could one day eliminate the need to ever change or recharge a battery," said Patrick Mercier, an electrical engineering professor at UC San Diego Jacobs School of Engineering and the study's senior author.   "We're building systems that have such low power requirements that they could potentially run for years on just a tiny battery," said Hui Wang, an electrical engineering Ph.D. student in Mercier's lab and the first author of the study.   Building ultra-low power, miniaturized electronic devices is the theme of Mercier's Energy-Efficient Microsystems lab at UC San Diego. Mercier also serves as co-director for the Center for Wearable Sensors at UC San Diego. A big part of his group's work focuses on boosting energy efficiencies of individual parts of an integrated circuit in order to reduce the power requirement of the system as a whole.   One example is the temperature sensor found in healthcare devices or smart thermostats. While the power requirement of state-of-the-art temperature sensors has been reduced to as low as tens of nanowatts, the one developed by Mercier's group runs on just 113 picowatts -- 628 times lower power.   Minimizing power   Their new approach involves minimizing power in two domains: the current source and the conversion of temperature to a digital readout.   Researchers built an ultra-low power current source using what are called "gate leakage" transistors -- transistors in which tiny levels of current leak through the electronic barrier, or the gate. Transistors typically have a gate that can turn on and off the flow of electrons. But as the size of modern transistors continues to shrink, the gate material becomes so thin that it can no longer block electrons from leaking through -- a phenomenon known as the quantum tunneling effect.   Gate leakage is considered problematic in systems such as microprocessors or precision analog circuits. Here, researchers are taking advantage of it -- they're using these minuscule levels of electron flow to power the circuit.   "Many researchers are trying to get rid of leakage current, but we are exploiting it to build an ultra-low power current source," Hui said.   Using these current sources, researchers developed a less power-hungry way to digitize temperature. This process normally requires passing current through a resistor -- its resistance changes with temperature -- then measuring the resulting voltage, and then converting that voltage to its corresponding temperature using a high power analog to digital converter.   Instead of this conventional process, researchers developed an innovative system to digitize temperature directly and save power. Their system consists of two ultra-low power current sources: one that charges a capacitor in a fixed amount of time regardless of temperature, and one that charges at a rate that varies with temperature -- slower at lower temperatures, faster at higher temperatures.   As the temperature changes, the system adapts so that the temperature-dependent current source charges in the same amount of time as the fixed current source. A built-in digital feedback loop equalizes the charging times by reconnecting the temperature-dependent current source to a capacitor of a different size -- the size of this capacitor is directly proportional to the actual temperature. For example, when the temperature falls, the temperature-dependent current source will charge slower, and the feedback loop compensates by switching to a smaller capacitor, which dictates a particular digital readout.   The temperature sensor is integrated into a small chip measuring 0.15 × 0.15 square millimeters in area. It operates at temperatures ranging from minus 20 C to 40 C. Its performance is fairly comparable to that of the state of the art even at near-zero-power, researchers said. One tradeoff is that the sensor has a response time of approximately one temperature update per second, which is slightly slower than existing temperature sensors. However, this response time is sufficient for devices that operate in the human body, homes and other environments where temperature do not fluctuate rapidly, researchers said.   Moving forward, the team is working to improve the accuracy of the temperature sensor. The team is also optimizing the design so that it can be successfully integrated into commercial devices.     Ref. ADT7410TRZ-REEL DS18B20

Toshiba Memory has announced development of the world’s first BiCS FLASH three-dimensional (3D) flash memory utilising Through Silicon Via (TSV) technology with 3-bit-per-cell (triple-level cell, TLC) technology. Shipments of prototypes for development purposes started in June, and product samples are scheduled for release in the second half of 2017. The prototype of this ground-breaking device will be showcased at the 2017 Flash Memory Summit in Santa Clara, California, United States, from August 7-10.Devices fabricated with TSV technology have vertical electrodes and vias that pass through silicon dies to provide connections, an architecture that realises high speed data input and output while reducing power consumption. Real-world performance has been proven previously, with the introduction of Toshiba’s 2D NAND Flash memory. Combining a 48-layer 3D flash process and TSV technology has allowed Toshiba Memory Corporation to successfully increase product programming bandwidth while achieving low power consumption. The power efficiency of a single package is approximately twice that of the same generation BiCS FLASH memory fabricated with wire-bonding technology. TSV BiCS FLASH also enables a 1-terabyte (TB) device with a 16-die stacked architecture in a single package. Toshiba Memory will commercialise BiCS FLASH with TSV technology to provide an ideal solution in respect for storage applications requiring low latency, high bandwidth and high IOPS/W, including high-end enterprise SSDs. Ref.KY32-CG7937AAKY32-CG7797AAT

Researchers at Tokyo Institute of Technology have devised a low-cost approach to developing all-solid-state batteries, improving prospects for scaling up the technology for widespread use in electric vehicles, communications and other industrial applications. Ever since batteries were invented over 200 years ago, there has been a drive to improve quality and performance at reduced costs.Compared to common lithium-ion batteries that contain lithium ion conducting liquids, all-solid-state batteries of the future promise a suite of advantages: improved safety and reliability, higher energy storage and longer life cycles. The discovery of ‘superionic’ conductors — solid crystals that enable fast movement of ions — is spurring the development of such dream batteries, but promising designs have so far relied on the use of rare metals such as germanium, making them too expensive for large-scale applications. Ryoji Kanno and colleagues at Tokyo Institute of Technology (Tokyo Tech) have now discovered a new material with a low-cost, scalable approach that involves substituting germanium for two more readily available elements: tin and silicon. The new material achieved an ionic conductivity that exceeds that of liquid electrolytes. Reporting their findings in Chemistry of Materials, the team states: "This germanium-free lithium conductor could be a promising candidate as an electrolyte in all-solid-state batteries." Due to its high chemical stability and ease of fabrication, Kanno says that the new material widens the possibilities of fine-tuning solid electrolytes to meet diverse industry and consumer needs. In 2011, Kanno and his team, working in collaboration with Toyota Motor Corporation and Japan's High Energy Accelerator Research Organisation (KEK), published a landmark paper in Nature Materials that introduced a solid electrolyte with the structure Li10GeP2S12 (LGPS). This material became an important forerunner in the race to develop viable all-solid-state batteries. It exhibited an ionic conductivity of 1.2x10-2S cm-1 at room temperature, a level comparable with — and even exceeding some — liquid electrolytes used in existing batteries. The team went on to design other solid electrolytes based on the same LGPS crystal structure, with promising results. In their latest study, the researchers kept the same framework structure of LGPS, and finely adjusted the ratio and positioning of the tin, silicon and other constituent atoms. The resulting material LSSPS (composition: Li10.35[Sn0.27Si1.08]P1.65S12 (Li3.45[Sn0.09Si0.36]P0.55S4)) achieved an ionic conductivity of 1.1x10-2S cm-1 at room temperature, almost reaching that of the original LGPS structure. Although further work will be required to optimise performance for different usage purposes, the new material raises hopes for low-cost production without sacrificing performance. Kanno envisions that in addition to meeting current battery needs across all sectors, all-solid-state batteries will expand the possibilities of responding to new user needs arising from the IoT and the shift towards smart systems, as well as powering robots, drones and space and aircraft technologies among others in future.  Ref.KY605-NH12VPKY605-NH15VP

In recent years Artificial intelligence (AI) has become a technology that global companies are desperately trying to take advantage of, as it is one of the most emerging and competitive technologies. However, a lot of AI technologies focus on the software, with operating speeds low which makes them a poor fit for mobile devices. For this reason big companies are focusing on developing AI with low power and high speeds, hoping to make AI fit for mobile use.   Professor Hoi-Jun Yoo of the Department of Electrical Engineering, along with his research team and collaboration with start-up company, UX Factory Co, has developed a semiconductor chip, CNNP (CNN Processor), which runs AI algorithms with ultra-low power, and K-Eye, a face recognition system using CNNP. Consisting of two different formats, the K-Eye series is available as a wearable type and a dongle type. The wearable type device can be used with a smartphone via Bluetooth, and it can operate for more than 24 hours with its internal battery. By conveniently hanging the K-Eye around their necks users can check information about people by using their smartphone or smart watch, which connects K-Eye and allows users to access a database via their smart devices. A smartphone with K-EyeQ, the dongle type device, can recognise and share information about users at any time.  It works by recognising an authorised user looking at the screen, which then automatically turns the smartphone on, without a fingerprint, passcode or iris authentication. The smartphone cannot be tricked by the user’s photograph, as it can distinguish whether an input face is coming from a saved photograph versus a real person. Other distinct features are carried out by the K-Eye series. Detecting a face at first and then recognising it is one, and it is possible to maintain ‘Always-on’ status with low power consumption of less than 1mW. The research team devised two key technologies to complete this: an image sensor with ‘Always-on’ face detection and the CNNP face recognition chip.  The ‘Always-on’ image sensor, the first key technology, is able to determine if there is a face in its camera range. Then, it can capture frames and set the device to operate only when a face exists, reducing the standby power significantly. Additionally the face detection sensor combines analogue and digital processing to reduce power consumption. Using this approach, the analogue processor, combined with the CMOS Image Sensor array, distinguishes the background area from the area likely to include a face, and the digital processor then detects the face only in the selected area. Therefore, it becomes effective in terms of frame capture, face detection processing, and memory usage.    Following this the second key technology, CNNP, is able to achieve incredibly low power consumption, by optimising a convolutional neural network (CNN) in the areas of circuitry, architecture, and algorithms. Specially designed to enable data to be read in a vertical direction as well as in a horizontal direction, the on-chip memory integrated in CNNP also has immense computational power with 1024 multipliers and accumulators operating in parallel and is capable of directly transferring the temporal results to each other without accessing to the external memory or on-chip communication network. Additionally, convolution calculations with a two-dimensional filter in the CNN algorithm are approximated into two sequential calculations of one-dimensional filters to achieve higher speeds and lower power consumption.  CNNP achieved 97% high accuracy but consumed only 1/5000 power of the GPU thanks to these new technologies. Face recognition can be performed with only 0.62mW of power consumption, and the chip can show higher performance than the GPU by using more power.  Developed by Kyeongryeol Bong, a PhD student under Professor Yoo, these chips were presented at the International Solid-State Circuit Conference (ISSCC) held in San Francisco earlier this year. CNNP, which has the lowest reported power consumption in the world, has achieved a huge amount of attention, which has led to the development of the present K-Eye series for face recognition.  Professor Yoo commented: “AI - processors will lead the era of the Fourth Industrial Revolution. With the development of this AI chip, we expect Korea to take the lead in global AI technology.”  Ref.MT9V022 OV05633

In this internet-connected age, all of our devices are constantly communicating with each other. Chances are you've got a phone, a laptop, a television, a car radio, maybe a smart home device or some other WiFi-capable appliance, along with a smartwatch or Bluetooth speaker. All of these devices are talking with each other and the wider world constantly. This is all done through radio signals. All of your devices communicate by sending and receiving radio signals at specific frequencies. But why don't cellphone calls collide against Wi-Fi signals? Mostly, it's because there are agreed-upon standards for what devices get to broadcast at what frequency. The radio spectrum is heavily partitioned so different kinds of traffic stay in their own lanes and all the data gets where it needs to go. A similar situation is playing out underwater. Under the sea, there are submarines, research vessels, robots, buoys, and tracking tags on animals, and they've all got to communicate. But radio signals don't work underwater, so the established radio communication standards are useless. Instead, underwater signals are sent via acoustic waves, but until recently there was no standard for which frequencies to use. That's all been changed now, thanks to a new standard being pioneered by NATO. Called JANUS—after the Roman god of gateways—the new system partitions the range of possible underwater communication frequencies and lets everything communicate with everything else. The JANUS protocol establishes a single frequency—11.5 kilohertz—that is reserved for initial communication between two systems, as well as frequencies for announcing a system's presence to everyone nearby. Once two crafts or robots make contact with each other, they can switch to a different frequency for extended communication. JANUS is opening the door to a better way to communicate underwater. Because of this new standard, all kinds of new collaborations are now possible. Entire fleets of robots can communicate with each other at a distance, communications buoys can send signals from the air into the water, and everyone can finally talk to one another. Considering the ocean floor is less explored than outer space, it's about time we figured out a way to communicate from there. Ref.CC3000MODRESP8266

Ion Transistors for the transport of both positive and negative ions, as well as biomolecules had been previously developed by a group of Organic Electronics research team at Linköping University. Now Tybrandt has now succeed in developing circuits using these Transistors similar to traditional silicon electronics. In essence of this technology we can build computer chips that can directly interface with our body cells.The major advantage of chemical circuit is that the charge carrier consists of chemical substances with various functions and this gives us new opportunities to regulate and control signal paths of Human Body Cells.In a conventional transistor there are three terminals Gate, Source and Drain. When signal is applied to Gate terminal, electrons flow from Source to Drain. Electrons are the charge carrier in conventional transistor, but in the new Ion Transistor the ionic neurotransmitter acetylcholine is the charge carrier. NAND gates and Inverters can be created using these Ion transistors, which means that it can be used to implement any logic function.Magnus Berggren, Professor of Organic Electronics and leader of the research group says that, it can be used to send signals to muscle synapses when our muscle signalling system may not works for some reasons and our chips works with common signalling substances such as acetylcholine.The research in Ion Transistors which can control and transport ions and charged biomolecules was begun before 3 years by Berggren (professor in Organic Electronics at the Department of Science and Technology at Linköping University) and Tybrandt (a doctoral student). Researchers at Karolinska Institute then used this Transistors to control the delivery of the signalling substance acetylcholine to individual cells. It hopes that it can restore the lost movement of paralysed peoples.Mr. Tybrandt in conjunction with Robert Forchheimer (Professor of Information Coding at LiU) has taken the next steps by developing chemical chips which contains logic gates, that allows the construction of all logic functions.Ref:KY56-C4706KY56-KSC5024RTUKY56-MJL21193G