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A microfluidic chip takes up a water sample, adds the necessary chemicals, and transports it to the detection site. What's the point? In this way, the water is to be analyzed fully automatically and with various parameters and at the lowest possible cost. A further developed chip prototype for water analysis devices has emerged from the MICROCHIP project at Fraunhofer Institute for Microengineering and Microsystems IMM. Whether in the waterworks, laboratory, in a swimming pool or from the tap - who would not like to have a quick and easy water analysis at hand. With the microfluidic lab-on-a-chip developed in the MICROCHIP project, samples can be analyzed fully automatically from just a few drops in a short time. Thus enabling personnel without training to detect six parameters relevant to water analysis in parallel with a low-cost measuring device additionally saves time and costs. Furthermore, user errors are eliminated with this methodology. Reagents cannot be mixed up and the amount of water suitable for the method is set by the chip. Mirror instead of transparency The chip achieves high measurement accuracy. Among other things, this is possible due to an extended path length and an adapted design that keeps the chip compact. Instead of an originally planned transmission solution, the project partners opted for a so-called mirror solution. The re-design of the hardware with different colored LEDs ultimately enables analytics for the photometry-based measurement method, in which colored water samples are evaluated. Credit card format packed with technology The chip ultimately reaches about the size of a credit card, combined with a lot of technology such as an electronic board with photometric sensors, ultrasonic mixers, pressure reservoirs as well as a peristaltic pump insertion for the chip along with a pressure mechanism that had to be accommodated in the small housing. Compared to previous solutions, this one is much more cost-effective. The project partners show that it is possible to perform multi-parameter water analyses in a polymer chip. They do not use complex and expensive technologies such as blister and freeze-drying. Instead, they dry the reagents directly in chambers in the chip. A simple peristaltic pump is used to direct the measuring liquid through the chip. As a result, the sensors measure the liquid colored by the reagents in the same measuring chamber as the previously colorless reference sample. The chip is manufactured by injection molding. To ensure that the chip is also pressure-tight to the outside, the channels in a black top shell and a transparent bottom shell are welded together using a laser beam process. Previous comparable systems for automated water analysis after adding the water sample in polymer chips are either too bulky or analyze fewer parameters in parallel. The demonstrator developed and implemented in the consortium is not yet ready for mass production. However, the results of the development and tests are already being used by one of the project partners, Water-i.d. GmbH, in the production of further water analysis devices and reagents. For more information, visit: https://www.imm.fraunhofer.de/en/press-publications/project-microchip.html

Like solar panels and wind turbines, the price of lithium-ion batteries has plummeted over this century, with a study from March estimating that cost has dropped by 97% worldwide since their introduction in 1991. Now, the same team of researchers has sought to explain why the price has fallen so much. Publishing their results in Energy and Environmental Science " Determinants of lithium-ion battery technology cost decline", they say that research and development (R&D), particularly in chemistry and materials science, has been the major factor in dropping the price of the batteries. The researchers, who are based at the Massachusetts Institute of Technology, US, examined a range of different financial and scientific documents from the past 30 years.“The data collection effort was extensive,” says co-author Dr Micah Ziegler. “We looked at academic articles, industry and government reports, press releases, and specification sheets. We even looked at some legal filings that came out. We had to piece together data from many different sources to get a sense of what was happening.” In total, according to Ziegler, the researchers collected “about 15,000 qualitative and quantitative data points, across 1000 individual records from approximately 280 references”. The researchers have previously used this method to examine the dropping price of solar cells and rising costs of nuclear energy. "We estimate that the majority of the cost decline, more than 50 percent, came from research-and-development-related activities,” says co-author Professor Jessika Trancik. Private-sector and government-funded research both contributed to this decline.The research helped improve a range of different parts of the lithium-ion landscape, including manufacturing systems, supply chains, and the designs of the batteries themselves. “The cost improvement emerged from a diverse set of efforts and many people, and not from the work of only a few individuals,” says Trancik. “The R&D contribution didn’t end when commercialisation began. In fact, it was still the biggest contributor to cost reduction,” adds Ziegler. The researchers say that there’s still much to be improved in lithium-ion batteries; this paper could help to provide direction for the next places to invest.“What are all the things that different decision makers could do?” asks Trancik. “What decisions do they have agency over so that they could improve the technology? [This is] important in the case of low-carbon technologies, where we’re looking for solutions to climate change and we have limited time and limited resources. “The new approach allows us to potentially be a bit more intentional about where we make those investments of time and money.” For more information, visit: https://cosmosmagazine.com/technology/energy/lithium-ion-batteries-cheaper-investment/

Speaker: Pål Morten Lindberget | Company: CondAlign AS | Date: 11-12 May 2021 | Full Presentation CondAlign’s technology represents a novel process for production of anisotropic, conductive films. Using an electric field to structure and align particles, the results in a z-axis conductive film structure. One product type we can produce is anisotropic conductive adhesive (ACA) films with thicknesses from a few µm to some hundreds µm and resistance below 0,01 Ohm/cm^2. With very high chain densities (pitch below 10µm), these films are currently being tested in several bonding processes, like FOB, FOF, COB, COF, as an alternative to traditional ACF. The process is demonstrated in roll-to-roll production, proofing it is scalable and cost effective. Morten Lindberget VP Business Development @ CondAlign Bio An enabler with 25 years international experience from leadership, sales and business development roles in technology consulting, contract manufacturing, medical device technology and scale up. Morten holds a MSc in Mech. Engineering from TU Delft, the Netherlands, and an Executive Master of Management from BI, Norway. Join TechBlick on an annual pass to join all live online conference or online version of onsite conference access library of on-demand talks (600 talks + PDFs) portfolio of expert led masterclass year-round platform https://www.techblick.com/ And do NOT miss our flagship event in Berlin on 17-18 OCT 2023 focused on Reshaping the Future of Electronics. This event attracts 550-600 participants from all the world and offers a superb ambience and dynamic exhibition floor. To learn more visit https://www.techblick.com/electronicsreshaped To see feedback about previous event see https://www.techblick.com/events-agenda

A new organic (carbon-based) semiconducting material has been developed that outperforms existing options for building the next generation of biosensors. An international research team led by KAUST is the first to overcome some critical challenges in developing this polymer. The work "Regiochemistry-Driven Organic Electrochemical Transistor Performance Enhancement in Ethylene Glycol-Functionalized Polythiophenes" was published in the Journal of the American Chemical Society Much research effort is currently expended into novel types of biosensors that interact directly with the body to detect key biochemicals and serve as indicators of health and disease. “For a sensor to be compatible with the body, we need to use soft organic materials with mechanical properties that match those of biological tissues,” says Rawad Hallani, a former research scientist in the KAUST team, who developed the polymer along with researchers at several universities in the U.S. and the U.K. Hallani explains that the polymer is designed for use in devices called organic electrochemical transistors (OECTs). For these types of devices, the polymer should allow specific ions and biochemical compounds to permeate into the polymer and dope it, which in turn can modulate its electrochemical semiconducting properties. “The fluctuation in the electrochemical properties is what we are actually measuring as an output signal of the OECT,” he says. The team had to confront several chemical challenges because even minor changes in the polymer’s structure can have a significant impact on performance. Many other research groups have tried to make this particular polymer, but the KAUST team is the first to succeed. Their innovation is based on polymers called polythiophenes with chemical groups called glycols attached in precisely controlled positions. Learning how to control the locations of the glycol groups in ways not previously achieved was a key aspect of the breakthrough. “Identifying the right polymer design to fit all the criteria that you are looking for is the tough part,” says Hallani. “Sometimes what can optimize the performance of the material can negatively affect its stability, so we need to keep in mind the energetic as well as the electronic properties of the polymer.” Sophisticated computational chemistry modeling was used to help achieve the right design. The team was also aided by specialized x-ray scattering analysis and scanning tunneling electron microscopy to monitor the structure of their polymers. These techniques revealed how the location of the glycol groups affected the material’s microstructure and electronic properties. “We are excited by the progress Rawad made on the polymer synthesis, and we are now looking forward to testing our new polymer in specific biosensor devices,” says Iain McCulloch of the KAUST team, who is also attached to the University of Oxford in the U.K. McCulloch says that the research group is now trying to improve the stability of their polymers and the sensors built from them, as they move from laboratory demonstrations toward real-world applications. For more information, visit: https://discovery.kaust.edu.sa/en/article/1148/building-a-better-biosensor-polymer

Human body communication (HBC) that takes advantage of the most conductive features of body tissues can provide highly secure and power-efficient data transmission among wearable, implanted and ingested medical devices, KAUST researchers have published this work "The Internet of Bodies: A Systematic Survey on Propagation Characterization and Channel Modeling" in IEEE Internet of Things Journal. The findings open the way for the interconnection of long-lasting wireless devices as the foundation for the internet of bodies (IoB). The internet of things (IoT) is a technology framework in which a myriad of devices can be interconnected to provide seamless functionality and unprecedented depth of data on the world around us. Autonomous vehicles and smart homes, for example, rely on IoT technologies for monitoring and control. But what if the same idea could be applied to monitoring our own bodies and alerting us to health signals? That is the concept behind the IoB. “The IoB is a network of wearable, implantable, ingestible and injectable smart objects that allows for in-, on- and off-body communications,” says Ahmed Eltawil. “For example, smartwatches, smart shoes, pacemakers, and cochlear implants could be interconnected to monitor our biomarkers.” However, interconnecting these devices using radio waves like those used in Wifi networks — the conventional go-to technology for such applications — can produce stray outward signals that could allow eavesdropping or biohacking, as well as using excess energy. Through a systematic investigation of potential IoB interconnection technologies, Eltawil and colleagues Abdulkadir Celik, Abeer Alamoodi and Khaled Salama revealed HBC to be the most promising. “HBC uses harmless tiny electrical signals to transmit data through conductive body tissue,” says Celik. “Not only does HBC use a thousand times less energy per bit than radio, it also benefits from much better channel quality.” The potential of HBC is not just limited to interdevice networking, however; due to the unique conductance characteristics of each person, the technology could also be used for bioauthentication, just like a fingerprint. “Imagine a scenario where simply touching a car steering wheel or the keys on your laptop can continuously authenticate that you are the owner,” says Celik. The researchers suggest that IoB using human body channels could be a disruptive technology in many sectors, such as personalized healthcare, remote patient monitoring, smart homes, assisted independent living, occupational health, and safety, fitness, sport, and entertainment. “While numerous technical challenges still need to be addressed, such as developing robust, seamless interfaces between the sensor and the human body, HBC certainly opens the possibility of realizing extremely compact, cheap, low-power body sensors,” Eltawil says. For more information, visit: https://discovery.kaust.edu.sa/en/article/1190/connect-the-internet-of-bodies

KAUST scientists have created micrometer-scale light-emitting diodes of unprecedented small size that could be used in mobile phone screens or televisions. They published their work "630-nm red InGaN micro-light-emitting diodes (<20 μm × 20 μm) exceeding 1 mW/mm2 for full-color micro-displays" in Photonics Research journal. Micrometer-scale light-emitting diodes (μLEDs) are the ideal building block for next-generation microLED displays used in head-mounted monitors, mobile phones, and televisions because they are bright, respond quickly, offer longevity, and consume little energy. KAUST researchers have shown that these scaled-down devices can efficiently emit light across the entire visible light spectrum. Just as with conventional LED displays, full-color μLEDs products will require arrays of blue, green, and red light sources. Nitride-based alloys are a group of semiconducting materials that offer one route to achieving this because, with the right chemical mix, they can emit all three colors. However, when nitride devices are reduced in size to micrometer scales, they become very poor emitters of light. “The main obstacle to reducing the size of the devices is the damage to the sidewalls of the LED structure generated during the fabrication process,” explains Ph.D. student Martin Velazquez-Rizo. “Defects provide an electrical path for a leakage current that does not contribute to the light emission.” This effect gets worse as the size of the LED shrinks, which has limited the LED size to approximately 400 by 400 micrometers. Velazquez-Rizo, along with his colleagues Zhe Zhuang, Daisuke Iida, and Kazuhiro Ohkawa, have developed bright red indium gallium nitride micro light-emitting diodes (µLEDs) of just 17 × 17 micrometers. The team used a thoroughly calibrated atom deposition technique to create a 10 by 10 array of red μLEDs. The damage to the μLED sidewalls was then eliminated using a chemical treatment. “We confirmed with atomic-scale observations that the sidewalls had high crystallinity after the treatment,” says Velazquez-Rizo. “Performing this type of observation requires specialized tools and sample preparation.” And the leader of the research Ohkawa agrees. “Without this microscope technology, we could not realize and confirm this achievement.” They observed very high output power of 1.76 milliwatts from each square millimeter on the device’s surface — a notable improvement on previous devices that reported an output power of less than 1 milliwatt per millimeter square. The team then demonstrated their red μLEDs with green and blue indium gallium nitride μLEDs to create a wide color-range device. “The next step in our research is to further improve the efficiency of our μLEDs and decrease their lateral dimensions below 10 micrometers,” says Velazquez-Rizo. For more information, visit: https://discovery.kaust.edu.sa/en/article/1179/full-color-leds-cut-down-to-size

An electrode coating just one molecule thick can significantly enhance the performance of an organic photovoltaic cell, KAUST researchers have found. The coating outperforms the leading material currently used for this task and may pave the way for improvements in other devices that rely on organic molecules, such as light-emitting diodes and photodetectors. The work "18.4 % Organic Solar Cells Using a High Ionization Energy Self-Assembled Monolayer as Hole-Extraction Interlayer" was published in Chemistry–Sustainability–Energy–Materials Journal. Unlike the most common photovoltaic cells that use crystalline silicon to harvest light, organic photovoltaic cells (OPVs) rely on a light-absorbing layer of carbon-based molecules. Although OPVs cannot yet rival the performance of silicon cells, they could be easier and cheaper to manufacture at a very large scale using printing techniques. When light enters a photovoltaic cell, its energy frees a negative electron and leaves behind a positive gap, known as a hole. Different materials then gather the electrons and holes and guide them to different electrodes to generate an electrical current. In OPVs, a material called PEDOT: PSS is widely used to ease the transfer of generated holes into an electrode; however, PEDOT: PSS is expensive, acidic, and can degrade the cell’s performance over time. The KAUST team has now developed a better alternative to PEDOT: PSS. They use a much thinner coating of a hole-transporting molecule called Br-2PACz, which binds to an indium tin oxide (ITO) electrode to form a single-molecule layer. The organic cell using Br-2PACz achieved a power conversion efficiency of 18.4 percent, whereas an equivalent cell using PEDOT: PSS reached only 17.5 percent. “We were very surprised indeed by the performance enhancement,” says Yuanbao Lin, Ph.D. student and member of the team. “We believe Br-2PACz has the potential to replace PEDOT: PSS due to its low cost and high performance.” Br-2PACz increased the cell’s efficiency in several ways. Compared with its rival, it caused less electrical resistance, improved hole transport, and allowed more light to shine through to the absorbing layer. Br-2PACz also improved the structure of the light-absorbing layer itself, an effect that may be related to the coating process. The coating could even improve the recyclability of the solar cell. The researchers found that the ITO electrode could be removed from the cell, stripped of its coating, and then reused as if it was new. In contrast, PEDOT: PSS roughens the surface of the ITO so that it performs poorly if reused in another cell. “We anticipate this will have a dramatic impact on both the economics of OPVs and the environment,” says Thomas Anthopoulos, who led the research. For more information, visit: https://discovery.kaust.edu.sa/en/article/1138/molecular-coating-enhances-organic-solar-cells

Printed/flexible electronics have long been touted as the technology that will make electronics ubiquitous. Promised applications include wireless sensors in packaging, skin patches that communicate with the internet, and buildings that detect leaks to enable preventative maintenance. However, until recently such applications have largely remained in the prototyping and development stages. However, 2021 has been an exciting year for printed electronics, with multiple applications reaching commercial adoption and significant funds flowing into the sector. Even where technologies are not yet commercialized, companies are increasingly transitioning from developing their technology and producing speculative demonstration prototypes to development and qualification projects for specific customers. Healthcare/wellness: Utilizing flexibility Successfully commercializing printed/flexible electronics requires identifying applications where its differences from conventional electronics add significant value. Electronic skin patches are a great example of this, with flexible thin-film devices improving patient comfort while enabling continuous monitoring of biometric parameters. Interest in electronic skin patches has really accelerated in 2021, with dedicated material portfolios being developed by major players such as Dupont and Henkel, and the patches being utilized in hospitals. This uptake in traction is partially attributed to COVID-19 since both patients and healthcare professionals are now much more comfortable with remote consultations that necessitate home monitoring. Furthermore, many healthcare systems are struggling with a backlog of patients after operations/screenings were canceled, creating an additional drive to adopt new technologies that can improve efficiency, for example by facilitating earlier discharge from the hospital. Automotive: Accompanying the transition to EVs While the transitions towards automotive electrification and autonomy attract plenty of attention, they are accompanied by the adoption of other technologies that to some extent fall under the radar. Increasing adoption of printed electronics is one such example, with applications in both interiors and exteriors. Interiors are especially promising targets for innovation that adds value to the occupant experience since it's trickier for manufacturers to differentiate EVs based on the powertrain. As such there are extensive opportunities for printed/flexible electronics to add additional functionality to the cockpit while facilitating efficient manufacturing. Examples include adding more and higher performance displays and capacitive control surfaces. Indeed, backlit capacitive touch sensors comprising inlayed transparent printed metal mesh films and thermoformed parts, developed by PolyIC, have been commercialized in Volkswagen models launched in 2021. There is also growing interest in heaters for automotive applications since EVs generate far less residual heat. While printed electronics are interested already used for some seat heaters, implementing heaters made from either resistive or positive temperature co-efficient conductive inks into surfaces would improve heating efficiency and hence slightly extend EV range. Transparent heaters, which can be made from either metal mesh, carbon nanotubes (CNTS), or silver nanowires, are also being developed and trialed, with initial target applications being headlight and sensor covers. Smart packaging: Technical innovations boost feasibility Smart packaging has received a significant boost towards widespread adoption in 2021, with two emerging players raising $10s of million in funding to scale up production and extend their technical capabilities. Defined as integrating electronic functionality such as antennas and sensors into the packaging to track its progress and condition through the supply chain and into the home, smart packaging has long been touted as a promising application for printed/flexible electronics. This is because, unlike conventional rigid electronics, printed/flexible electronics are theoretically compatible with very high throughput roll-to-roll (R2R) production to enable the very low production costs required. However, despite the widespread adoption of RFID tags, smart packaging with integrated sensing has thus far remained limited to niche applications. This is primarily because the cost targets for most smart packaging applications are extremely challenging, especially since a power source or energy harvesting capability, one or more sensors, processing IC, and an antenna all need to be incorporated. Furthermore, smart packaging generally only adds value when it facilitates an integrated solution together with the software. This usually requires entering a market at scale and being simultaneously adopted by multiple players in the supply chain. In an attempt to reduce the cost of smart packaging hardware, thus opening up the technology to higher volume applications, innovative hardware technologies are being developed. PragmatIC, a UK-based firm that produces natively flexible metal oxide ICs, raised $80m in Series C funding in October 2021. The key value proposition of Pragmatic's ICs is their low cost, potentially less than 1 US cent each. While RFID is the initial application, slightly more complex ICs for sensing applications are also being developed. Another promising innovation for smart packaging is sensors that harvest energy from ambient electromagnetic radiation. Developed by US-based Wiliot, which raised $200m in a Series C funding round, these battery-free wireless sensors communicate via Bluetooth. Event-based sensing is used to only communicate when the position of the sensor changes, and hence reduce power consumption. ICs from both PragmatIC and Wiliot will be mounted on flexible substrates, with antennas often produced from conductive inks - this emerging manufacturing methodology that combines printing and mounting components is termed 'Flexible Hybrid Electronics (FHE)' and covered in a specific IDTechEx report. With this incoming investment facilitating growth in technologies that resolve some longstanding pain points, 2021 could turn out to be there year that kickstarts the adoption of smart packaging. Smart buildings and IoT: Combining sensing and energy harvesting IoT devices, defined here as a network of wirelessly connected sensors for both domestic and industrial applications, offer benefits such as predictive maintenance and condition monitoring. They represent a great opportunity for printed/flexible electronics since they need to be affordable and have a compact form factor to fit into buildings, industrial equipment, etc. Despite the clear value proposition, powering IoT devices remains a challenge since replacing batteries is both wasteful and expensive when the maintenance time is included. An emerging candidate to resolve this issue is organic photovoltaics (OPV). While the large-scale adoption of organic photovoltaics has previously proved challenging, the energy harvesting technology is extremely well suited to indoor energy harvesting since it is more efficient than silicon photovoltaics under low-intensity diffuse radiation. The films are also cheap to produce via solution processing, while their flexible, thin-film form factor improves durability and integration possibilities. Indoor OPV cells for low-power IoT devices are being developed by companies such as Epishine, Dracula Technologies, and Ribes Tech. This technology gained traction in 2021, with Epishine's OPV cells installed in commercially available facilities management products. Other applications of printed/flexible electronics for printed electronics in smart buildings take advantage of the ability to produce relatively simple large area devices at an accessible price point. Applications include heating and leak detection, either integrated into building materials or retrofitted. In 2021, early-stage UK firm Bare Conductive launched Laiier, targeting these applications - low-cost leak detection is proving especially compelling to the insurance industry, with multiple projects in development. The year ahead This commercialization of printed/flexible electronics is expected to continue in 2022 across all the technologies and applications outlined above, with capacitive touch sensors made from printed metal mesh, OPV cells for indoor energy harvesting, and increasingly flexible electronic skin patches all gaining traction. Resource: https://www.idtechex.com/en/research-article/printed-electronics-emerging-applications-accelerate-towards-adoption/25269

Elitac Wearables & UMC Utrecht developed a smart shirt that helps guide neurosurgeons during skull base surgery to prevent damage to critical structures such as veins and nerves. Neuroimaging and navigation are widely used for drilling tasks in skull base surgery: It involves generating an individualized anatomical view of the patient beforehand and then tracking the surgeon’s drill bit relative to critical structures on a screen during surgery. It is very beneficial in helping surgeons avoid damaging critical structures, but its major drawback is that surgeons must keep switching between the microscope view of the patient and the neuronavigation screen. This constant switching between views during complicated and 7+ hour-long procedures may cause fatigue and therefore, surgical errors. ​ How does the NeuroShirt solve this problem? It connects to the neuronavigation system and continuously indicates both the distance and direction of critical structures through haptic feedback (vibrations). This way, surgeons no longer have to split their focus between patient and screen. Benefits Decreased likelihood of surgical errors due to fatigue Haptic feedback minimizes the need to keep switching views, and therefore reduces fatigue and the risk of surgical errors. Real-time, continuous haptic feedback No interruptions because the surgeon is switching between views. Distance AND direction of critical structures The NeuroShirt conveys information about both the distance and direction of critical structures. Moreover, research demonstrates that haptic feedback is very effective at indicating directional information from a user-centered point of view. Reduced risk of sensory overload ORs are busy environments with many visual and auditory stimuli. Using touch to convey information unburdens the surgeon’s eyes and ears. Distinct & intuitive A haptic feedback wearable can always be felt: Even in the case of auditory and visual overload, surgeons are still aware of “the tap on the shoulder”. This greatly reduces the likelihood that vital information is missed. Effective risk communication Research has demonstrated that combining visual and tactile information can be more effective than visual information alone in the communication of risks. For more information, visit: https://elitacwearables.com/projects/neuroshirt/?utm_source=press&utm_medium=li&utm_campaign=pr

KAUST scientists have developed a simple cooling system driven by the capture of passive solar energy could provide low-cost food refrigeration and living space cooling for impoverished communities with no access to the electricity grid. The system, which has no electrical components, exploits the powerful cooling effect that occurs when certain salts are dissolved in water. After each cooling cycle, the system uses solar energy to evaporate the water and regenerate the salt, ready for reuse. The work was published in the Energy & Environmental Science journal "Conversion and storage of solar energy for cooling" “Hot regions have high levels of solar energy, so it would be very attractive to use that solar energy for cooling,” says Wenbin Wang, a postdoc in Peng Wang’s lab. In many parts of the world, there is a greater need for cooling because of climate change, but not every community can access electricity for air conditioning and refrigeration. “We conceptualized an off-grid solar-energy conversion and storage design for green and inexpensive cooling,” Professor Wang says. The team designed a two-step cooling and regeneration system, with the cooling step based upon the fact that dissolving certain common salts in water absorbs energy, which rapidly cools the water. After comparing a range of salts, ammonium nitrate (NH4NO3) proved to be the standout performer, with a cooling power more than four times greater than its closest competitor, ammonium chloride (NH4Cl). The ammonium nitrate salt’s exceptional cooling power can be attributed to its high solubility. “NH4NO3’s solubility reached 208 grams per 100 grams of water, whereas the other salts were generally below 100 grams,” Wenbin says. “This salt’s other advantage is that it is very cheap and already widely used as fertilizer,” he adds. Once collected, the salt effectively represents a stored form of solar energy, ready to be reused for cooling again when required. The system has good potential for food storage applications, the team showed. When the salt was gradually dissolved in water in a metal cup placed inside a polystyrene foam box, the temperature of the cup fell from room temperature to around 3.6 degrees Celsius and remained below 15 degrees Celsius for over 15 hours. Once the salt solution reached room temperature the team used solar energy to evaporate the water using a bespoke cup-shaped 3D solar regenerator. The cup was made from a material designed to absorb as much of the solar spectrum as possible. As the water evaporated, the NH4NO3 crystals grew over the cup’s outer wall. “The crystallized salt can be collected automatically as the salt drops off due to gravity,” Wenbin says. Once collected, the salt effectively represents a stored form of solar energy, ready to be reused for cooling again when required. For more information, visit: https://discovery.kaust.edu.sa/en/article/1174/strong-sunlight-powers-passive-cooling-device

Tiny luminescent particles are used in more and more products today: from smartphones to OLED televisions to car headlights. For industry, exact knowledge of luminescence efficiency is crucial. The Bundesanstalt für Materialforschung und -prüfung (BAM) is developing reliable measurement methods for this purpose, thus closing an important gap in standardization. Luminescent materials are finding more and more applications in daily life: They are used in medical technology in diagnostic procedures, in photovoltaics, in security codes on banknotes, in the displays of LED or OLED televisions, smartphones or e-book readers, and in lighting technology. The trend here is from particles in the micrometer range to those with nanometer sizes, which have particularly advantageous scattering properties and can show a high luminescence yield. The decisive factor for all applications of these materials is the efficiency of their photoluminescence, in short: their luminescence efficiency. This quantity presents a direct measure of the number of light quanta or photons that the particles emit compared to those they absorb. This is also referred to as the luminescence quantum yield. This key parameter determines the brightness of the substances. It is, therefore, a decisive indicator for companies that manufacture or use such materials for evaluating and comparing the quality, performance, and suitability of different luminous particles. However, to date, there is only one international standard for determining the quantum yield, which depends on many external factors such as temperature or the surrounding medium. This covers only transparent (non-scattering) samples that are comparatively easy to measure. More complicated measurements of scattering particles are not covered. But particularly these materials are increasingly relevant for industrial applications. This imposes increasing problems for companies that produce luminescent functional materials such as typical phosphors and so-called converter materials or use them in the field of lighting and display technology. They need reliable methods for determining the quantum yield for quality and product control. Developing these methods by themselves would be too tedious even for large companies. BAM whose mandate includes the promotion of German industry, has been studying luminescent materials for many years, developing reference methods and materials for the life and material sciences, and providing reference data. Now BAM is launching a joint project that is intended to bring scientific results quickly into standardization and thus into the application. The project is financed by the Federal Ministry of Economics within the framework of the funding program "Knowledge and Technology Transfer through Patents and Standards". In cooperation with Schott AG, which has been producing optical materials for more than 100 years, BAM will develop reliable methods for determining the quantum yield of scattering luminescent particles and materials. Special focus is laid on materials of particular economic interest: Novel converter materials which, for example, when combined with blue laser and LED light, give car headlights a yellow glow more comfortable for humans. These materials are in high demand in the industry for many different applications. Schott AG will provide luminescent materials directly from the application and, together with BAM, will develop measurement procedures suitable for industrial process control. These measurement procedures will be eventually standardized and timely transferred to international standardization. "With this joint project we want to close an important gap in order to strengthen the market position of German companies in this field in the medium term," says Ute Resch-Genger from BAM, who is leading the project For more information, visit: https://www.bam.de/Content/EN/News-announcements/2021/AnalyticalSciences/2021-07-29-luminescent-materials.html https://www.bam.de/Content/EN/Press-Releases/2021/AnalyticalSciences/2021-03-31-fluorescent-reference-materials.html

A method that combines screen-printable composite and metallic inks could make foldable electronics easier and cheaper to manufacture at industrial scales. These devices, developed at KAUST, can be mounted on various supports, including nonplanar surfaces, and could enable many Internet of Things applications. The work "All Screen-Printed, Polymer-Nanowire Based Foldable Electronics for mm-Wave Applications" was published in Advanced Materials Technologies. Next-generation technology such as automotive radars for self-driving cars, smart buildings, and wearable sensors will depend more heavily on the high-frequency millimeter-wave band, including 5G. To date, large-scale manufacturing approaches to make foldable electronics have focused on developing metallic inks and printing conductive patterns and have overlooked dielectric substrates. There has been a range of barriers to the use of substrates such as paper and some polymer films in foldable electronics. These substrates involve fabrication processes that are too constraining and complex for mass production and cannot produce multilayered or ultrathin flexible devices. They also have a dielectric loss that exceeds the requirements for millimeter-wave devices. Atif Shamim and coworkers have now devised a composite ink composed of ceramic particles dispersed in the polymer acrylonitrile-butadiene-styrene (ABS). They used this new ink to generate extremely flexible, large-area dielectric substrates with tunable lateral dimensions, thickness, and permittivity. They screen-printed the ink onto glass and, after drying, simply peeled off the substrates from the support. The substrates presented a minimum thickness of a few microns that could be increased through successive printing passes. They also exhibited a low dielectric loss at 28 gigahertz, which is suitable for 5G antennas. The researchers screen-printed a silver nanowire-based ink on the dielectric substrates to build conductive patterns. The patterned films maintained high and stable electrical performance when rolled or folded into half — a result of the polymer binder present in the ink. Furthermore, they retained their performance when incorporated into a four-layer circuit consisting of alternating metal-patterned and dielectric layers. This suggests that the screen-printable inks can be used in multilayer structures, such as multilayer printed circuit boards and automotive radars. For proof of concept, the researchers screen-printed a flexible quasi-Yagi antenna on a dielectric substrate to show that the device performed well in the millimeter-wave band when bent or folded. “Our approach will be beneficial for novel 5G antennas and accelerate the implementation of 5G,” says postdoc Weiwei Li. The team is now exploring potential applications of their approach to other electronic devices. Li says that both inks are compatible with roll-to-roll processing, which can help meet the high demand for wearable sensors at low costs. “We expect fabrication costs to be extremely low, to the extent that the devices will become disposable,” Shamim says. For more information, visit: https://onlinelibrary.wiley.com/doi/10.1002/admt.202100525