Dr Isaac Rosen, Senior Scientific Researcher at Copprint Contact us info@copprint.com Visit our virtual booth My name is Isaac Rosen, and I lead an R&D team at Copprint where we work on the development of future products as well as solving customer challenges. I am responsible for our activities to create a process for soldering on conductive traces. Electrical component assembly on printed electronics is primarily achieved today with ECAs, a strike difference from the practice in traditional electronics manufacturing where soldering is standard. This difference arises mainly from the difficulties in soldering on printed silver traces. Copprint pastes are copper-based, enabling excellent electrical properties that outperform silver pastes – higher conductivity and lower cost. It is possible to solder on traces formed with Copprint paste using standard off-the-shelf solder pastes. Strong solder bonds are formed with small resistors soldered on FR4, with up to 4 kgf needed to disconnect (via die shear force measurements). Figure 1: Copprint copper paste, PCB with soldered components. Visit our virtual booth. Copprint develops and manufactures conductive copper paste for various applications, including PCB board printing, membrane switches, RFID tags, and PV cells. We have copper pastes suitable for multiple substrates such as FR4, Paper, Glass, PI, PET, and more. Copprints product portfolio can be found here, including links inside for TDS, MSDS, application notes, and how-to videos. Copprint pastes can be used to replace silver pastes (expensive and toxic) as well as to replace polluting etching processes. A key requirement for electronic manufacturing is component attachment to a printed circuit board. So far, when using silver pastes for printed electronics, good solderability with conventional solder pastes was difficult to obtain. The primary reason for the problem is that an IMC layer (Intermetallic Compound) cannot form between Tin, the main component in solder pastes, and silver metal. Therefore, manufacturers needing to attach components refrain from soldering and mainly use silver-based ECAs. Such ECAs are far more expensive than solder pastes (Silver vs. Tin prices) and far less standard in the PCB industries. With Copprint pastes printed on FR4, we identified several compatible solder pastes, enabling the formation of a strong solder bond, with a proper IMC connection between the solder and the copper. The method advised (by solder paste manufacturers) for screening solder pastes was to visually look at wetting of the solder paste on the printed Cu surface after reflowing. The theory was that no wetting or de-wetting is a sign that the solder paste is not compatible. We learned from careful experimentation that wetting is not always the proper indication for compatibility and the potential to form a good soldered bond. In fact, this approach gave many false negatives. A much better approach is to test the actual performance (formation of a strong soldered bond) of different solder pastes by soldering small (1206) chips to screen printed copper traces and measuring the die shear force needed to detach the chip. Figure 2: Video showing applying solder paste, placing components, and soldering on printed copper traces in a reflow oven. Visit our virtual booth. First, Copprint paste is screen printed on the substrate, followed by drying and sintering to obtain a conductive copper pattern (video). Then solder paste is applied with stencil printing, components are placed and soldered by reflow (the process in which the solder paste is heated, melts, and re-solidifies to form the bond) - See figure 2. Finally the soldered bond strength is tested as can be seen in Figure 3. Figure 3: Photo of Die shear force test on 1206 SMD resistor chips soldered with SAC305 KOKI 955LV. Using this approach, we found Compatible solder pastes that work well: form a strong bond that is hard to detach, requiring applying over 3kgf pressure to cause failure and detachment of the soldered chip. Non-compatible solder pastes do not work well: no solder bond is formed, and the chips can be detached with a gentle push. Furthermore, we found that for compatible solder pastes, the failure mode was detachment between the Cu and the substrate, while with non-compatible pastes, the failure mode was between the solder paste and the printed Cu surface. In addition, only with compatible pastes, an IMC layer was formed between the solder and the printed copper layer, which is the fundamental proof of the formation of a solder bond (figure 4). Figure 4: Cross-section of solder bond, 1206 SMD LED soldered with SAC305 on Cu printed on FR4 substrate, micrograph on the right shows the presence of IMC. Visit our virtual booth. The reason only some tested solder pastes were compatible is probably due to the flux system in each paste. Some fluxes work on the surface of copper patterns made with our copper paste, and some do not. As the fluxs formulation in the tested solder pastes are unknown (trade secrets), empirical testing is needed to approve a solder paste as compatible. After establishing a good procedure for identifying compatible solder pastes, we tested a wide range of SAC305 and SnPb solder pastes on FR4, as well as SnBi and SnBiAg solder pastes on PET, resulting in a list of approved solder pastes, which can be supplied on request (info@copprint.com). Die shear forces above 2kgf were obtained with specific pastes from Henkel, Koki, AIM, Shenmao, Balvar Zinn and more. A very interesting and valuable finding is that soldering can be done on the printed copper traces without any post-processing. Even after few weeks of standard storage, a good die sheer force was achieved. PET is an important substrate in printed electronics due to its low price, availability and durability. However, its low melting point does not enable the use of SAC or SnPb solder pastes. Compatible SnBi based solder pastes were identified, enabling a die shear force above 2 kgf on 125 um PET Details and recommended reflow profiles can be supplied on request via info@copprint.com. To conclude, a simple soldering process for reliably connecting components on printed electronics was demonstrated. We expect faster adoption of printed electronics as component placement is more standard than the existing ECA method. This will happen with a transition from silver to copper for printing PCBs made on standard substrates like FR4 and newer substrates like PET.

A new research project is setting out to find a solution to the growing problem of electronic waste by creating the world’s first controlled degradable integrated circuits. Researchers from the University of Glasgow’s James Watt School of Engineering have won a £1.5m grant from the Engineering and Physical Sciences Research Council (EPSRC) for the project. Their work could help address the growing problem of toxic waste created during the manufacture and disposal of common electronic items like computers, mobile phones, and fitness trackers. In 2019 alone, consumers threw away more than 53 million tonnes of electronic waste, much of which contain hazardous waste in components like batteries and circuit boards. It is estimated that less than 20% of this is properly recycled and the scale of the problem is growing each year. The Glasgow team will work with a range of industrial and governmental partners to develop high-performance electronic materials which can be safely disposed of at the end of their useful lives. This includes designing electronics that are more easily recycled into new forms or by using components that naturally degrade altogether to form benign by-products. The project, known as Green Energy-Optimised Printed Transient Integrated Circuits, or GEOPIC, builds on existing expertise at the University’s Bendable Electronics and Sensing Technologies (BEST) group. Researchers from the BEST group have already developed numerous new forms of electronics, including bendable and stretchable printed circuits which offer performance similar to that of conventional silicon-based electronics, and wearable systems that can be powered by devices based on human sweat. They have also developed methods to reliably print high-performance circuitry onto flexible surfaces. Over the next three years, the research project will build on that expertise to create silicon nanomembrane-based high-performance flexible and printed integrated circuits on new forms of biodegradable materials. Once the circuits are no longer needed, the silicon can be recycled and the materials will degrade naturally. Professor Ravinder Dahiya, of the James Watt School of Engineering, is the principal investigator of GEOPIC. Professor Dahiya said: “There is an urgent need for action to tackle the problem of electronic waste, without losing the cross-cutting transformative power of electronics. Currently, electronic production processes can produce a significant amount of chemical waste. The devices which are produced by those processes can contain components that are, at best, only partially recyclable. “By setting out to develop new types of electronics which make their eventual disposal an integral part of their production right from the start, we hope that we can find a way to help stem the flood of electronic waste and find commercial applications for the electronics we develop once this initial research phase comes to a close.” Dr. Jeff Kettle, the co-investigator of the project aid, “I’m proud to be working on this project with my colleagues in the BEST group and our partners across the UK. I’m confident that we can find new methods of dealing with this urgent problem. We are delighted by the support of a wide range of project partners allowing us to work with material specialists, electronics manufacturers, environmental scientists, and policymakers, who will provide input as the project progresses.” The GEOPIC partners are ARM Ltd, IQE (Europe) Ltd, the National Physical Laboratory, PragmatIC Printing Ltd, Printed Electronics Ltd, the Scottish Environmental Protection Agency, and Zero Waste Scotland. More information: https://www.gla.ac.uk/news/headline_833936_en.html

Researchers have developed a 46-inch woven display with smart sensors, energy harvesting and storage integrated directly into the fabric. An international team of scientists has produced a fully woven smart textile display that integrates active electronic, sensing, energy, and photonic functions. The functions are embedded directly into the fibers and yarns, which are manufactured using textile-based industrial processes. The researchers, led by the University of Cambridge, say their approach could lead to applications that sound like sci-fi: curtains that are also TVs, energy-harvesting carpets, and interactive, self-powered clothing and fabrics. This is the first time that a scalable large-area complex system has been integrated into textiles using an entirely fiber-based manufacturing approach. Their results are reported in the journal Nature Communications. Despite recent progress in the development of smart textiles, their functionality, dimensions, and shapes are limited by current manufacturing processes. Integrating specialized fibers into textiles through conventional weaving or knitting processes means they could be incorporated into everyday objects, which opens up a huge range of potential applications. However, to date, the manufacturing of these fibers has been size limited, or the technology has not been compatible with textiles and the weaving process. To make the technology compatible with weaving, the researchers coated each fiber component with materials that can withstand enough stretching so they can be used on textile manufacturing equipment. The team also braided some of the fiber-based components to improve their reliability and durability. Finally, they connected multiple fiber components together using conductive adhesives and laser welding techniques. Using these techniques together, they were able to incorporate multiple functionalities into a large piece of woven fabric with standard, scalable textile manufacturing processes. The resulting fabric can operate as a display, monitor various inputs, or store energy for later use. The fabric can detect radiofrequency signals, touch, light, and temperature. It can also be rolled up, and because it’s made using commercial textile manufacturing techniques, large rolls of functional fabric could be made this way. The researchers say their prototype display paves the way to next-generation e-textile applications in sectors such as smart and energy-efficient buildings that can generate and store their own energy, Internet of Things (IoT), distributed sensor networks, and interactive displays that are flexible and wearable when integrated with fabrics. “Our approach is built on the convergence of micro and nanotechnology, advanced displays, sensors, energy, and technical textile manufacturing,” said Professor Jong-min Kim, from Cambridge’s Department of Engineering, who co-led the research with Dr. Luigi Occhipinti and Professor Manish Chhowalla. “This is a step towards the full exploitation of sustainable, convenient e-fibers and e-textiles in daily applications. And it’s only the beginning.” “By integrating fiber-based electronics, photonics, sensing, and energy functionalities, we can achieve a whole new class of smart devices and systems,” said Occhipinti, also from Cambridge’s Department of Engineering. “By unleashing the full potential of textile manufacturing, we could soon see smart and energy-autonomous Internet of Things devices that are seamlessly integrated into everyday objects and many other sector applications.” The researchers are working with European collaborators to make the technology sustainable and useable for everyday objects. They are also working to integrate sustainable materials as fiber components, providing a new class of energy textile systems. Their flexible and functional smart fabric could eventually be made into batteries, supercapacitors, solar panels, and other devices. The research was funded in part by the European Commission and the Engineering and Physical Sciences Research Council (EPSRC), part of UK Research and Innovation (UKRI). More information: https://www.cam.ac.uk/research/news/scientists-develop-fully-woven-smart-display

Speaker: Jedrzej Kufel | Company: ARM | Date: 11-12 May 2021 | Full Presentation Conventional silicon technology has embedded at least one integrated circuit into every smart device on Earth. However, it faces key challenges to make everyday objects smarter. Cost is the most important factor but flexibility and conformability are highly desirable. Our approach is to develop integrated circuits using flexible electronic fabrication techniques, thus paving the way towards natively-flexible LSI and VLSI ICs. Jedrzej Kufel Staff Research Engineer @ Arm Bio Dr Jedrzej Kufel is a Staff Research Engineer. He joined Arm in 2014, working in the IoT product team before moving to Research in 2016. His current interests are in the area of low-power integrated circuit design using flexible/printed electronics, validation and test methodologies and circular economy. Jedrzej holds a MEng in Mechatronics and Robotic Systems from University of Liverpool and a PhD from University of Southampton. 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

- Can They Be Competitive On The Battery Market Within Automotive Applications? Speaker: Ines Miller | Company: P3 | Date: 9-10 Feb 2022 | Full Presentation Increasing battery demand and requirements towards high performance cells are pushing lithium-ion technology to its limits. Recent developments in solid-state technology have led to a high level of media attention, and both start-ups and large cell manufacturers are intensively working on the industrialization of their next-generation technology as major challenge. The competitiveness of currently leading players regarding technology, scalability and costs aspects will be evaluated and discussed in the presentation. 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/ Our next battery-related event will take place on 15-16 FEB 2023, covering 1) Solid-State Batteries: Innovations, Promising Start-Ups, & Future Roadmap 2) Battery Materials: Next-Generation & Beyond Lithium Ion The speakers include: General Motors, Graphenix Development, Brookhaven National Laboratory, Fraunhofer IKTS, RWTH Aachen University, Lawrence Livermore National Laboratories, Meta Materials Inc, Skeleton Technologies, Solid State Battery Inc, Argonne National Laboratories, OneD Battery Sciences, VTT, Leyden Jar Technologies B.V., b-Science, Rho Motion, Wevo-Chemie, LiNA Energy, CNM Technologies, Ionblox, Empa, Zinc8 Energy Solutions, Avicenne Energy, Echiontech, South8 Technologies, Basquevolt, NanoXplore, Chasm, Li Metal, Sila Nanotechnologies, Quantumscape (tentative), Fraunhofer ISI, etc https://www.techblick.com/

SmartNanotubes Technologies, a German startup that has developed the world’s first micro power multi-channel gas detector chip for the mass market, has raised € 2.4 million in its Series A funding round. Lead investors are Cottonwood Technology Fund and duotec GmbH. Game changer in the gas sensor market SmartNanotubes Technologies, based near Dresden, operates on the principle of an electronic nose similar to the array of receptors in the human nose. Current gas sensor arrays are expensive, large in size, and characterized by low sensitivity and high power consumption. The carbon nanotubes chips of SmartNanotubes, however, are highly sensitive, energy-efficient, compact, and low-cost. SmartNanotubes is a game-changer in the gas sensor market as its chips can measure multiple gases while most existing technologies can only detect one gas at a time. Product quality, safety, and security In a team of four people, Dr. Viktor Bezugly and Dr. Birte Sönnichsen co-founded SmartNanotubes in the summer of 2020 after a three-year know-how transfer project at LifeScience Inkubator (LSI). Bezugly started his research on carbon nanotubes at DresdenUniversity of Technology twelve years ago. “I’m delighted to make my research available to the public by setting up this company. As of now, our target markets include product quality in materials, food, and medical applications,’’ said Viktor Bezugly. “Other areas include safety and security in transport, consumer goods, and manufacturing through the early detection and identification of volatile organic compounds (VOCs) and hazardous gases. Moreover, SmartNanotubes can control air quality, for example in industrial environments such as cleanrooms.” Multiple product lines and markets In its previous seed round, SmartNanotubes received support from LSI Pre-Seed-FoTechnologiegründerfonds Sachsen (TGFS), TUDAG TU Dresden Aktiengesellschaft, and a private investor. The current investment round is led by Cottonwood Technology Fund and German corporate duotec GmbH and complemented by Mittelständische Beteiligungsgesellschaft Sachsen. “We first met SmartNanotubes two years ago at the High-Tech Venture Days in Dresden. At the same time, we received a recommendation from a large corporate about its outstanding technology,’’ said Alain le Loux, General Partner of Cottonwood Technology Fund. “SmartNanotubes is the perfect example of a deep tech company with disruptive innovation. It is truly rewarding to help them in the pre-customer and pre-revenue stage with launching their technology in the global market. In particular, because SmartNanotubes offers the possibility of technology-selling in multiple markets and product lines.’’ For duotec, the investment in SmartNanotubes is a continuation of their innovation strategy. “We are expanding our portfolio of expertise through innovative and disruptive technologies,” said Arthur Rönisch, Managing Director and CIO of duotec. “This novel sensor technology means we are ahead of the competition by more than just a nose, literally. Together with our customers, we will incorporate this know-how into products.” “We are very excited to have both Cottonwood and duotec on board as our newest investors,’’ said co-founder Dr. Birte Sönnichsen. “duotec is well known as a very professional electronics production partner. And Cottonwood brings us – besides their deep-tech startup experience – a global network of relevant corporates including Asia and the United States”. About SmartNanotubes Technologies SmartNanotubes Technologies GmbH has developed the first micropower multi-channel gas detector chip for the mass market. The sensor elements contain fine-tuned nanomaterials which make the chip highly sensitive, energy-efficient, compact, and low-cost. It can detect multiple gases and volatile organic compounds (VOCs). Use cases range from environmental and security applications, home and industrial safety to wearables and IoT lifestyle products. Furthermore, the multi-channel gas detector chip can easily be integrated into different appliances. For more information, please visit: Press Contact Dr. Viktor Bezugly E-mail: bezugly@smart-nanotubes.com Tel: +49 351 850 73 684 About duotec GmbH duotec is a globally operating electronics service provider. duotec has invested for years in innovative manufacturing technologies as well as in basic research and the development of state-of-the-art microelectronics. duotec uses its existing know-how to think out of the box with the aim of pushing innovations and always being a little ahead of the competition. This claim is expressed in the new slogan” Ahead of Innovation”. For more information, please visit: www.duotec.net Press Contact Arthur Rönisch, Managing Director and CIO E-Mail: arthur.roenisch@duotec.net Tel: +49 2353 1390 6160 About Cottonwood Technology Fund Cottonwood Technology Fund is an early-stage venture capital fund. Its investment focus is on hard science and deep tech, providing (pre-)seed and early-stage funding to IP-driven companies. Cottonwood makes impact investments in Key Enabling Technologies like Photonics, Micro- and Nanoelectronics, Advanced Materials, Nanotechnology, Medical Technology, Cleantech, Energy, Advanced Manufacturing, and Robotics. Its regional focus is Northwest Europe and Southwest USA. Current and prior investments include Sarcos Robotics (NASDAQ: STRC), Sencure, Skorpios Technologies, FibeRio (acquired by Clarcor), xF Technologies, Flexiramics, BayoTech, Respira Therapeutics (sold to Prana Bio), Infinitum Electric, TriLumina (acquired by Lumentum), sound energy, Exagen (NASDAQ: XGN), and OPNT. For more information, please visit: www.cottonwood.vc Press Contact Alain le Loux, General Partner E-Mail: alain@cottonwood.vc Tel: +31 53 82 00 798 Press release: https://smart-nanotubes.com/news/

Zurich, Switzerland - Jan. 20, 2022 - In its continuing efforts to discover and develop innovative technologies for the packaging industry, Amcor (NYSE: AMCR; ASX: AMC) announced today its strategic investment in PragmatIC Semiconductor, a world leader in ultra, low-cost electronics. Based in the United Kingdom, PragmatIC Semiconductor develops flexible, integrated circuits beyond the scope of conventional electronics. Their ConnectIC® family of radio frequency identification and near-field communications (RFID/NFC) integrated chips can be embedded into the packaging to store and relay information to devices such as smartphones. This technology will enable smart packaging applications across the entire product lifecycle – from manufacturing and supply chain management to consumer engagement and even material recovery. Frank Lehmann, Vice President of Open Innovation and Corporate Venturing at Amcor, said, “As the global diversified packaging leader, Amcor is well-positioned to tap into early-stage, cutting-edge innovation around sustainability and digitization. We are delighted to partner with PragmatIC Semiconductor to explore ways to leverage and integrate these flexible, integrated circuits into our portfolio of more sustainable packaging solutions.” Scott White, PragmatIC Semiconductor CEO, said, “We are pleased to partner with an industry leader like Amcor. This investment is a testament to the value Amcor continues to place on innovation and our collective vision on how packaging can be used to connect customers and consumers with the information they need.” Amcor’s USD$5 million investment was part of the Series C funding round of more than USD$90 million for PragmatIC Semiconductor. This investment follows the recent investment by Amcor Corporate Venturing in ePac in April of 2021. More information: https://assets.ctfassets.net/f7tuyt85vtoa/2EiZK1ojS8ZgYU0U4ezxR/0bc729974b7cb300ff4beaad3dfb6bc9/PR_Amcor_PragmatIC.pdf https://www.amcor.com/media/news/amcor-announces-strategic-investment-pragmatic-semiconductor

9 - 10 February 2022 | 14:00 - 20:00 CET | Virtual Event Platform TechBlick’s event on 9-10 February 2022 covers two major themes in the battery industry: (1) solid-state batteries and (2) frontier materials beyond standard Li-ion chemistry. In doing so, TechBlick brings together a handpicked world-class agenda consisting of end-users, manufacturers, promising start-ups, as well as renowned market analyst groups. This event provides the opportunity to learn about the latest technology trends, disruptive start-ups, scale-up and production strategies, green approaches, OEM requirements, and market analysis and forecasts. It is truly a unique agenda with unparalleled networking opportunities. Add to your Calendar iCalendar (majority of email clients) | Google Calendar | Microsoft Outlook Calendar Office 365 Calendar | Yahoo Calendar Leading Global Speakers Include: ... and many more ... Themes: Solid-StateStart-Ups Batteries | Next-Gen and Beyond Li-Ion | Promising Start Ups | Market Forecasts | Start-Up Landscape Analysis | Scale-Up Techniques and Successes | Roll-to-Roll | Emerging Solid-State Electrolyte Material Families | Pure and Composite Silicon Anodes | AI and Simulation in Material Discovery and Optimization | LiS | Graphene, CNTs, and VACNTs | Reactive Metals | Existing Emerging Novel Cathodes Materials for Li-ion and SSBs | Aqueous, Binder-Free and/or Green Solutions | 3D Batteries | Additively Manufactured Batteries | Dry Electrode Technology Networking in ‘In-Person Virtual’ Platform The video below shows you how ‘in-person virtual’ works, creating the buzz, energy, and engagement level of physical in-person events with great opportunities for serendipitous ‘coffee-break’ discussions and discovery. What is included in an Online Annual Pass? For 12 months, you can access ALL TechBlick online events, benefit from the library of past content, join past and future industry-led masterclasses, and participate in networking activities. You will also receive a 50% discount on our in-person physical events. The Annual Pass is 600 € per year. However, until 4 February 2022, you can save 100 €, making it 500 € per year, equivalent to some 42 € per month. To benefit from the discount, use the following code at registration: Save100Euros ALL LIVE (online) and on-demand conferences for 12 months Access to the community-centric platform (see the demo here) A growing library of over 300 past state-of-the-art presentations from past events All online INTERACTIVE ‘In-Person Virtual’ networking activities Join virtual exhibition suppressing in-person physical interactions (see the demo here) The growing portfolio of industry-led masterclasses 50% discount on the in-person physical event on Future of Electronics RESHAPED

Breakthrough regulates household temperature without consuming natural gas or electricity Scientists have developed an all-season smart-roof coating that keeps homes warm during the winter and cools during the summer without consuming natural gas or electricity. Research findings reported in the journal Science point to a groundbreaking technology that outperforms commercial cool-roof systems in energy savings. “Our all-season roof coating automatically switches from keeping you cool to warm, depending on outdoor air temperature. This is energy-free, emission-free air conditioning and heating, all in one device,” said Junqiao Wu, a faculty scientist in Berkeley Lab’s Materials Sciences Division and a UC Berkeley professor of materials science and engineering who led the study. Today’s cool roof systems, such as reflective coatings, membranes, shingles, or tiles, have light-colored or darker “cool-colored” surfaces that cool homes by reflecting sunlight. These systems also emit some of the absorbed solar heat as thermal-infrared radiation; in this natural process known as radiative cooling, thermal-infrared light is radiated away from the surface. The problem with many cool-roof systems currently on the market is that they continue to radiate heat in the winter, which drives up heating costs, Wu explained. “Our new material – called a temperature-adaptive radiative coating or TARC – can enable energy savings by automatically turning off the radiative cooling in the winter, overcoming the problem of overcooling,” he said. A roof for all seasons Metals are typically good conductors of electricity and heat. In 2017, Wu and his research team discovered that electrons in vanadium dioxide behave like metal to electricity but an insulator to heat – in other words, they conduct electricity well without conducting much heat. “This behavior contrasts with most other metals where electrons conduct heat and electricity proportionally,” Wu explained. Vanadium dioxide below about 67 degrees Celsius (153 degrees Fahrenheit) is also transparent to (and hence not absorptive of) thermal-infrared light. But once vanadium dioxide reaches 67 degrees Celsius, it switches to a metal state, becoming absorptive of thermal-infrared light. This ability to switch from one phase to another – in this case, from an insulator to metal – is characteristic of what’s known as a phase-change material. To see how vanadium dioxide would perform in a roof system, Wu and his team engineered a 2-centimeter-by-2-centimeter TARC thin-film device. TARC “looks like Scotch tape, and can be affixed to a solid surface like a rooftop,” Wu said. In a key experiment, co-lead author Kechao Tang set up a rooftop experiment at Wu’s East Bay home last summer to demonstrate the technology’s viability in a real-world environment. A wireless measurement device set up on Wu’s balcony continuously recorded responses to changes in direct sunlight and outdoor temperature from a TARC sample, a commercial dark roof sample, and a commercial white roof sample over multiple days. How TARC outperforms in energy savings The researchers then used data from the experiment to simulate how TARC would perform year-round in cities representing 15 different climate zones across the continental U.S. Wu enlisted Ronnen Levinson, a co-author on the study who is a staff scientist and leader of the Heat Island Group in Berkeley Lab’s Energy Technologies Area, to help them refine their model of roof surface temperature. Levinson developed a method to estimate TARC energy savings from a set of more than 100,000 building energy simulations that the Heat Island Group previously performed to evaluate the benefits of cool roofs and cool walls across the United States. Finnegan Reichertz, a 12th-grade student at the East Bay Innovation Academy in Oakland who worked remotely as a summer intern for Wu last year, helped to simulate how TARC and the other roof materials would perform at specific times and on specific days throughout the year for each of the 15 cities or climate zones the researchers studied for the paper. The researchers found that TARC outperforms existing roof coatings for energy saving in 12 of the 15 climate zones, particularly in regions with wide temperature variations between day and night, such as the San Francisco Bay Area, or between winter and summer, such as New York City. “With TARC installed, the average household in the U.S. could save up to 10% electricity,” said Tang, who was a postdoctoral researcher in the Wu lab at the time of the study. He is now an assistant professor at Peking University in Beijing, China. Standard cool roofs have high solar reflectance and high thermal emittance (the ability to release heat by emitting thermal-infrared radiation) even in cool weather. According to the researchers’ measurements, TARC reflects around 75% of sunlight year-round, but its thermal emittance is high (about 90%) when the ambient temperature is warm (above 25 degrees Celsius or 77 degrees Fahrenheit), promoting heat loss to the sky. In cooler weather, TARC’s thermal emittance automatically switches to low, helping to retain heat from solar absorption and indoor heating, Levinson said. Findings from infrared spectroscopy experiments using advanced tools at Berkeley Lab’s Molecular Foundry validated the simulations. “Simple physics predicted TARC would work, but we were surprised it would work so well,” said Wu. “We originally thought the switch from warming to cooling wouldn’t be so dramatic. Our simulations, outdoor experiments, and lab experiments proved otherwise – it’s really exciting.” The researchers plan to develop TARC prototypes on a larger scale to further test its performance as a practical roof coating. Wu said that TARC may also have the potential as a thermally protective coating to prolong battery life in smartphones and laptops, and shield satellites and cars from extremely high or low temperatures. It could also be used to make temperature-regulating fabric for tents, greenhouse coverings, and even hats and jackets. Co-lead authors of the study were Kaichen Dong and Jiachen Li. The Molecular Foundry is a nanoscience user facility at Berkeley Lab. This work was primarily supported by the DOE Office of Science and a Bakar Fellowship. The technology is available for licensing and collaboration. If interested, please contact Berkeley Lab’s Intellectual Property Office, ipo@lbl.gov. More information: https://newscenter.lbl.gov/2021/12/16/roof-year-round-energy-savings/

Wireless, fully implantable device gives temporary pacing without requiring removal. Researchers at Northwestern and George Washington universities (GW) have developed the first-ever transient pacemaker — a wireless, battery-free, fully implantable pacing device that disappears after it’s no longer needed. The thin, flexible, lightweight device could be used in patients who need temporary pacing after cardiac surgery or while waiting for a permanent pacemaker. All components of the pacemaker are biocompatible and naturally absorb into the body’s biofluids over the course of five to seven weeks, without needing surgical extraction. The device wirelessly harvests energy from an external, remote antenna using near-field communication protocols — the same technology used in smartphones for electronic payments and in RFID tags. This eliminates the need for bulky batteries and rigid hardware, including wires (or leads). Not only can leads introduce infections, but they also can become enveloped in scar tissue, causing further damage when removed. The study was published in the journal Nature Biotechnology. The paper demonstrates the device’s efficacy across a series of large and small animal models. “Hardware placed in or near the heart creates risks for infection and other complications,” said Northwestern’s John A. Rogers, who led the device’s development. “Our wireless, transient pacemakers overcome key disadvantages of traditional temporary devices by eliminating the need for percutaneous leads for surgical extraction procedures — thereby offering the potential for reduced costs and improved outcomes in patient care. This unusual type of device could represent the future of temporary pacing technology.” “Sometimes patients only need pacemakers temporarily, perhaps after an open heart surgery, heart attack, or drug overdose,” said Dr. Rishi Arora, a cardiologist at Northwestern Medicine who co-led the study. “After the patient’s heart is stabilized, we can remove the pacemaker. The current standard of care involves inserting a wire, which stays in place for three to seven days. These have potential to become infected or dislodged.” “The transient electronics platform opens an entirely new chapter in medicine and biomedical research,” said GW’s Igor Efimov, who co-led the study with Rogers and Arora. “The bioresorbable materials at the foundation of this technology make it possible to create a whole host of diagnostic and therapeutic transient devices for monitoring progression of diseases and therapies, delivering electrical, pharmacological, cell therapies, gene reprogramming and more.” Rogers is the Louis Simpson and Kimberly Querrey Professor of Materials Science and Engineering, Biomedical Engineering and Neurological Surgery in the McCormick School of Engineering and Feinberg School of Medicine and the director of the Querrey Simpson Institute for Bioelectronics. Arora is a professor of medicine at Feinberg and co-director of the Center for Arrhythmia Research. Efimov is the Alisann and Terry Collins Professor of Biomedical Engineering at GW. Ditching restrictive, risky leads Currently, to set up temporary pacing after open-heart surgery, surgeons must sew on temporary pacemaker electrodes on the heart muscle during surgery. These have leads that exit the front of a patient’s chest, connecting to an external pacing box that delivers a current to control the heart’s rhythm. When the temporary pacemaker is no longer needed, physicians remove the pacemaker electrodes. Although uncommon, potential complications of implanted temporary pacemakers include infection, dislodgement, torn or damaged tissues, bleeding, and blood clots. With Northwestern and GW’s transient pacemaker, surgeons and patients can sidestep this potentially risky procedure. The fully implantable device is light and thin — 250 microns thick and weighing less than half a gram. Soft and flexible, it encapsulates electrodes that softly laminate onto the heart’s surface to deliver an electrical pulse. “Instead of using wires that can get infected and dislodged, we can implant this leadless biocompatible pacemaker,” Arora said. “The circuitry is implanted directly on the surface of the heart, and we can activate it remotely. Over a period of weeks, this new type of pacemaker ‘dissolves’ or degrades on its own, thereby avoiding the need for physical removal of the pacemaker electrodes. This is potentially a major victory for post-operative patients. “With further modifications, it eventually may be possible to implant such bioresorbable pacemakers through a vein in the leg or arm,” he added. “In this instance, it also may be possible to provide temporary pacing to patients who have suffered a heart attack or to patients undergoing catheter-based procedures, such as transcatheter aortic valve replacement.” Prioritizing patient comfort Northwestern Medicine cardiac surgeon Dr. Duc Thinh Pham, who was not involved with the research, imagines a transient pacemaker undoubtedly would make his patients more comfortable. With current pacemakers, patients often feel discomfort for days after the leads are inserted. Then, they must limit their movements and activities in order to prevent the leads from dislodging. “This transient pacemaker is brilliant,” said Pham, who has performed more than 2,000 cardiac surgeries throughout his career. “In addition to addressing the primary issue of occasional post-cardiac surgery patients needing temporary pacing due to blockages or arrhythmias, the device addresses the secondary issue of patient comfort, ability to move freely and rehabilitate. If successful, this device will greatly improve a patient’s postoperative course.” Disappearing act This is the second example of bioresorbable electronic medicine from the Rogers lab, which has been studying transient electronics for over a decade. In 2018, Rogers and colleagues demonstrated the world’s first bioresorbable electronic device — a biodegradable implant that speeds nerve regeneration. The team’s bioresorbable devices are completely harmless — similar to absorbable stitches. After fully degrading, the devices completely disappear through the body’s natural biological processes. “There is clearly a need for better temporary cardiac pacemakers,” said Dr. Bradley Knight, the Chester C. and Deborah M. Cooley Distinguished Professor of Cardiology at Feinberg and coauthor of the study. “When I first learned about the bioresorbable nerve stimulator, I contacted Professor Rogers to explore the possibility of using this technology to pace the heart. He had already started working with Dr. Efimov to develop a small version of a bioresorbable pacemaker as a proof of concept. We then worked with both teams to develop a larger version of a bioresorbable, leadless, cardiac pacemaker that could be effective on a human scale. It’s a great example of what we can create at Northwestern by bridging the expertise in engineering and medicine.” Depending on the patient, a temporary pacemaker might be needed anywhere from a couple of days to several weeks. By varying the composition and thickness of the materials in the device, Rogers’ team can control the precise number of days it remains functional before dissolving. “We build these devices out of different types of safe, bioresorbable materials and in optimized architectures to ensure stable operation over a time period somewhat longer than is clinically necessary,” Rogers said. “We can tailor the devices to address a broad spectrum of relevant lifetimes. Transient technologies, in general, could someday provide therapy or treatment for a wide variety of medical conditions — serving, in a sense, as an engineering form of medicine.” The paper, “Fully bioresorbable, leadless, battery-free cardiac pacemaker,” was supported by the Leducq Foundation (RHYTHM award), National Institutes of Health (award numbers R01-HL141470, R01-HL140061, and R01-HL125881), the American Heart Association (award number 19PRE34380781, AF SFRN), the National Science Foundation (award number 1842165) and the Ford Foundation. The paper’s co-first authors are Yeon Sik Choi, Rose Yin, Jahyun Koo, and Anna Pfenniger. More information: https://news.northwestern.edu/stories/2021/06/first-ever-transient-pacemaker-harmlessly-dissolves-in-body/

pH sensor S-301 PET 190 μm Foil sensor for pH monitoring pH 4.5 – pH 9 The S-301 is a foil sensor with electrodes for electrochemical pH determination of samples. The accensors pH-sensor consists of two electrodes (a pH-sensitive and a non-sensitive Ag/AgCl reference electrode) on a transparent PET foil. The readings are taken by measuring the open circuit potential/voltage between both electrodes. Potential (E) and pH have a linear relationship (between the operating range of pH 4.5 to pH 9) so the pH of an unknown analyte solution can be calculated using the pre-determined slope and an offset E value (E0 determined by measuring the potential in a calibration buffer of known pH). The reference electrode and overall sensor can be used in analytes with different chloride concentrations thanks to a solid-state electrolyte layer. Once used, the sensor must be kept hydrated for further application and not allowed to dry out. The foil carrier is made of transparent PET material and the sensor is flexible, although care should be taken do not to bend the electrode spots. A connection between sensor and measurement electronics can be established via accensors connect or ZiF-connector. Contact pads are covered with oxidation protection. The data given refers to the use of the sensor in combination with the ACO accensors D-300 measurement device and our accensors iOS application. The measuring output will display the measured potential (in mV) or if the sensor is calibrated (one point software calibration at 21 oC or two-point at other temperature) output can be given as pH. Note that this sensor is somewhat light-sensitive, and the long-term stability (during use) will be reduced when used in brightly lit conditions. pH sensor S-302 PET 190 μm Foil sensor for pH monitoring pH 5.5 – pH 10 The S-302 is a foil sensor with electrodes for electrochemical determination of pH of samples. The accensors pH-sensor consists of two electrodes (a pH-sensitive and a non-sensitive Ag/AgCl reference electrode) on a transparent PET foil. The readings are taken by measuring the open circuit potential/voltage between both electrodes. Potential (E) and pH have a linear relationship (between the operating range of pH 5.5 to pH 10) so the pH of an unknown analyte solution can be calculated using the pre-determined slope and an offset E value (E0 determined by measuring the potential in a calibration buffer of known pH). The reference electrode and overall sensor can be used in analytes with different chloride concentrations thanks to a solid-state electrolyte layer. Once used, the sensor must be kept hydrated for further application and not allowed to dry out. The foil carrier is made of transparent PET material and the sensor is flexible, although care should be taken not to bend the electrode spots. A connection between sensor and measurement electronics can be established via accensors connect or ZiF-connector. Contact pads are covered with oxidation protection. The data given refers to the use of the sensor in combination with the ACO accensors D-300 measurement device and our accensors iOS application. The measuring output will display the measured potential (in mV) or if the sensor is calibrated (one point software calibration at 21 °C or two-point at other temperature) output can be given as pH. All mechanical dimensions are valid at 25 °C ambient temperature, if not differently indicated. All data except the mechanical dimensions only have information purposes and are not to be understood as assured characteristics. Technical changes without previous announcement as well as mistakes reserved. Load with extreme values during a longer period can affect the reliability. Typing errors and mistakes reserved. Product specifications are subject to change without notice. More information: https://accensors.com/ph-sensor-s301-ph-sensor-s302/

FaceBit can monitor the wearer’s health, sense heartbeat through the face. Northwestern University engineers have developed a new smart sensor platform for face masks that they are calling a “Fitbit for the face.” Dubbed “FaceBit,” the lightweight, quarter-sized sensor uses a tiny magnet to attach to any N95, cloth, or surgical face mask. Not only can it sense the user’s real-time respiration rate, heart rate, and mask wear time, it also may be able to replace cumbersome tests by measuring mask fit. All this information is then wirelessly transmitted to a smartphone app, which contains a dashboard for real-time health monitoring. The app can immediately alert the user when issues — such as elevated heart rate or a leak in the mask — unexpectedly arise. The physiological data also could be used to predict fatigue, physical health status, and emotional state. Although a tiny battery powers the device, FaceBit is designed to harvest energy from any variety of ambient sources — including the force of the user’s breathing, motion, and heat from a user’s breath as well as from the sun. This extends the sensor’s battery life, lengthening the time between charges. “We wanted to design an intelligent face mask for health care professionals that do not need to be inconveniently plugged in during the middle of a shift,” said Northwestern’s Josiah Hester, who led the device development. “We augmented the battery’s energy with energy harvesting from various sources, which means that you can wear the mask for a week or two without having to charge or replace the battery.” The research was published last week in the Proceedings of the ACM on Interactive, Mobile, Wearable and Ubiquitous Technologies. In the study, researchers found FaceBit’s accuracy was similar to clinical-grade devices, and the battery lasted longer than 11 days between charges. More information is available at facebit health. Hester is an assistant professor of computer science, computer engineering, and electrical engineering and the Breed Junior Professor of Design at Northwestern’s McCormick School of Engineering. Approximating the fit test Before designing FaceBit, Hester and his collaborators first interviewed doctors, nurses, and medical assistants to better understand their needs for smart face masks. In a series of surveys, all clinicians indicated that the quality of mask fit was most important — especially when working directly with patients with viral infections. To ensure their N95 masks are properly sealed to their faces, health care workers periodically undergo a 20-minute “fit test.” During this process, health care workers first put on an N95 respirator followed by a clear hood over their entire head. Another worker then pumps either sweet or bitter aerosol mists into the hood. The concentration of the aerosol is gradually increased inside the hood until it can be detected by the person wearing the respirator. If the wearer tastes bitter or sweet before a certain number of aerosol pumps, then the mask is not properly sealed. Although Hester’s FaceBit cannot yet replace this cumbersome process — which is a long-standing challenge in the medical industry — it can ensure the mask retains proper fit between testing events. If the mask becomes loose throughout the day or if the user bumps the mask during an activity, for example, FaceBit can alert the wearer. “If you wear a mask for 12 hours or longer, sometimes your face can become numb,” Hester said. “You might not even realize that your mask is loose because you cannot feel it or you are too burnt out to notice. We can approximate the fit-testing process by measuring mask resistance. If we see a sudden dip in resistance, that indicates a leak has formed, and we can alert the wearer.” Face-centric bio-sensing But the FaceBit can assess more than mask fit — it also can monitor the person wearing the mask in real-time. By gathering various physiological signals — such as heart and respiratory rates — FaceBit can help wearers better understand their own bodies in order to make beneficial health decisions. All health information, including mask, fit and wear time, are displayed on the accompanying smartphone app. According to Hester, every time a person’s heart beats, their head moves an imperceptibly tiny amount. FaceBit can sense that subtle motion — and differentiate it from other motions — in order to calculate heart rate. “Your heart is pushing a lot of blood through the body, and the ballistic force is quite strong,” Hester said. “We were able to sense that force as the blood travels up a major artery to the face.” Because stressful events can elicit physiological responses, including rapid breathing, FaceBit can use that information to alert the user to take a break, go for a walk or take some deep breaths to calm down. Hospital systems also could use this data to optimize shift and break schedules for their workers. And because heart rate and respiration rate are so tightly entangled with each other, having the ability to effortlessly monitor both could open new research possibilities. Battery-free future An expert in sustainable, battery-free technology, Hester hopes his team or others eventually will be able to make FaceBit completely battery free. Now, the wearer’s breathing and movements or the sun can extend the battery-freethe battery’s life. But, in the future, harvested thermal and kinetic energy could solely power the device. Although his team evaluated the device on volunteers in real-world scenarios, Hester said FaceBit still needs to undergo clinical trials and validation. The team released the project as open source and open hardware so others can build and validate the device. “FaceBit provides the first step toward practical on-face sensing and inference, and provides a sustainable, convenient, comfortable option for general health monitoring for COVID-19 frontline workers and beyond,” Hester said. “I’m really excited to hand this off to the research community to see what they can do with it.” The project, “FaceBit: Smart Face Masks Platform,” was supported by the National Science Foundation’s Grants for Rapid Response Research for addressing the COVID-19 pandemic (award number CNS-2032408). FaceBit was a collaboration with Nabil Alshurafa, assistant professor of preventative medicine in Northwestern University Feinberg School of Medicine and of computer science in McCormick. More information: https://news.northwestern.edu/stories/2022/01/fitbit-for-the-face-can-turn-any-face-mask-into-smart-monitoring-device/