National Nanomanufacturing Network

'Bulletproof' battery: Kevlar membrane for safer, thinner lithium rechargeables

National Nanomanufacturing Network - January 29, 2015 - 9:19am
New battery technology from the University of Michigan should be able to prevent the kind of fires that grounded Boeing 787 Dreamliners in 2013. The innovation is an advanced barrier between the electrodes in a lithium-ion battery. Made with nanofibers extracted from Kevlar, the tough material in bulletproof vests, the barrier stifles the growth of metal tendrils that can become unwanted pathways for electrical current. A U-M team of researchers also founded Ann Arbor-based Elegus Technologies to bring this research from the lab to market. Mass production is expected to begin in the fourth quarter 2016. "Unlike other ultra strong materials such as carbon nanotubes, Kevlar is an insulator," said Nicholas Kotov, the Joseph B. and Florence V. Cejka Professor of Engineering. "This property is perfect for separators that need to prevent shorting between two electrodes."Lithium-ion batteries work by shuttling lithium ions from one electrode to the other. This creates a charge imbalance, and since electrons can't go through the membrane between the electrodes, they go through a circuit instead and do something useful on the way. But if the holes in the membrane are too big, the lithium atoms can build themselves into fern-like structures, called dendrites, which eventually poke through the membrane. If they reach the other electrode, the electrons have a path within the battery, shorting out the circuit. This is how the battery fires on the Boeing 787 are thought to have started. "The fern shape is particularly difficult to stop because of its nanoscale tip," said Siu On Tung, a graduate student in Kotov's lab, as well as chief technology officer at Elegus. "It was very important that the fibers formed smaller pores than the tip size." While the widths of pores in other membranes are a few hundred nanometers, or a few hundred-thousandths of a centimeter, the pores in the membrane developed at U-M are 15-to-20 nanometers across. They are large enough to let individual lithium ions pass, but small enough to block the 20-to-50-nanometer tips of the fern-structures. The researchers made the membrane by layering the fibers on top of each other in thin sheets. This method keeps the chain-like molecules in the plastic stretched out, which is important for good lithium-ion conductivity between the electrodes, Tung said. "The special feature of this material is we can make it very thin, so we can get more energy into the same battery cell size, or we can shrink the cell size," said Dan VanderLey, an engineer who helped found Elegus through U-M's Master of Entrepreneurship program. "We've seen a lot of interest from people looking to make thinner products." Thirty companies have requested samples of the material. Kevlar's heat resistance could also lead to safer batteries as the membrane stands a better chance of surviving a fire than most membranes currently in use. While the team is satisfied with the membrane's ability to block the lithium dendrites, they are currently looking for ways to improve the flow of loose lithium ions so that batteries can charge and release their energy more quickly. The study, "A dendrite-suppressing solid ion conductor from aramid nanofibers," (http://www.nature.com/ncomms/2015/150127/ncomms7152/full/ncomms7152.html) appeared online Jan. 27 in Nature Communications. Source: University of Michigan (http://ns.umich.edu/new/multimedia/slideshows/22645-bulletproof-battery-kevlar-membrane-for-safer-thinner-lithium-rechargeables)

Fully transparent, rollable electronics built with a graphene/carbon nanotube backbone

National Nanomanufacturing Network - January 29, 2015 - 9:00am
The coming age of wearable, highly flexible and transparent electronic devices will rely on essentially invisible electronic and optoelectronic circuits. In order to have close to invisible circuitry, one must have optically transparent thin-film transistors (TFTs). In order to have flexibility, one needs bendable substrates. Both flexible electronics and transparent electronics have been demonstrated before, but never rollable electronics that are also fully transparent at the same time. This has now been achieved by a team of researchers in Korea, who have successfully built rollable and transparent electronic devices that are not only lightweight, but also don't break easily. To manufacture flexible electronics, one needs a starting material – the substrate – on which to build-up the device. In order for the final product to be flexible, the substrate of course also has to be flexible. In fact, it is the substrate that determines, to a large extent, the overall flexibility of the final product. So if the substrate is flexible to an extent of being rollable – which can be achieved making it very thin – the final product will also, to some extent, be rollable. Of course, the semiconductors, dielectrics, and metals making up the electronic device, should also be similarly flexible (or soft), otherwise faults will occur. Plastics are the obvious choice for flexible substrates as the substrates are also required to be insulating (nonconductive) in most applications. Other obvious advantages of plastics are that they are lightweight and non-breakable. A team led by Professor Jin Jang, Director of the Department of Information Display (http://display.khu.ac.kr/) at Kyung Hee University, has achieved this by overcoming two major challenges associated with the manufacture of flexible electronics: The temperature restriction of plastic substrates (<100°C) and the difficulty of handling flexible electronics during the fabrication process. They reported their findings in ACS Applied Materials Interfaces ("Fully Transparent and Rollable Electronics" (http://dx.doi.org/doi:10.1021/am506937s)). "To overcome the temperature restriction we chose our plastic substrate to be polyimide (PI), which is a polymer of imide monomers," Jang explains to Nanowerk. "PI has high chemical and heat resistance and when it is colorless, which is the case of this research, it withstands processing temperatures around 300°C." The researchers also chose an amorphous oxide semiconductor – amorphous-indium-gallium-zinc-oxide (a-IGZO) – which assures good device performance even when sputter-deposited at low temperatures. For consistency, they also chose a zinc-based metal, indium-zinc-oxide (IZO), for the metal electrodes – i.e. the gate, source, and drain electrodes of the field-effect transistors making up the electronic devices. "Both the a-IGZO and IZO have large band-gaps, and therefore, are transparent to visible light," says Jang. "As the dielectrics are also transparent and the substrate (PI) is colorless, the final product is see-through with a transmittance of 70% for the full circuit device. The colorless PI (CPI) is 15 µm thick and the thickness of the electronic devices is ∼1 µm, resulting in a total thickness of the fabricated thin-film transistor of only ∼16 µm. Hence, the electronic devices are rollable." In order to deal with the second major challenge – the difficulty of handling flexible electronics during the fabrication process – the researchers used a carrier glass substrate on which the CPI is first spin-coated from solution, and then detached from after device fabrication. Being around 0.7 mm in thickness, the carrier glass is rigid enough to provide mechanical support for the CPI, without which accurate layer registration is impossible during photolithography. This is because standalone plastics substrates can warp, shrink, or bulge at high temperatures. "A rigid carrier substrate is, therefore, a necessity when vacuum processes and photolithography are involved," Jang notes. "However, the way the flexible substrate is attached to the rigid carrier substrate is important as it has to be detached from the carrier substrate after device fabrication. The use of adhesive materials/glues to attach flexible substrates to carrier substrates is not recommended as most adhesives cannot withstand high processing temperatures." An alternative method is to spin-coat the flexible substrate from solution onto the carrier substrate. Although this method avoids the use of adhesive materials, it is very difficult to detach the flexible substrate from the carrier substrate afterwards because bonds between the two have a tendency of strengthening during the fabrication process. "The current solution is to deposit a thin layer such as amorphous-silicon between the flexible substrate and the carrier substrate, which can be evaporated by a laser to release the flexible substrate from the carrier substrate after device fabrication," says Jang. "Given the high cost of installing laser equipment, the complexity of the laser detachment process, and the limitations of the laser beam size, we felt their was a need for a better method." In their research, Jang's team do not use adhesive material or lasers. Neither do they deposit a layer of amorphous-silicon between the carrier glass and the CPI. Instead, they spin coat a mixture of carbon nanotubes (CNT) and graphene oxide (GO) to a thickness of 1 nm from solution onto of the carrier glass before spin coating the CPI. "As the CNT/GO layer has a flake like structure with CNT links, it decreases the area where the CPI contacts the glass, thereby reducing its adhesion to glass," explains Jang. "Inserting the CNT/GO layer also doesn't cost much because only a few drops are required to achieve a thickness around 1 nm." After fabrication, only a small amount of mechanical force is required to detach the CPI from the glass. According to the scientists, the beauty of having the CNT/GO layer is that it bonds stronger with the CPI compared to the glass, such that it remains embedded to the backside of the CPI after detachment – providing mechanical support to the flexible electronics and making the rollable electronics wrinkle-free. Electronic devices built on plastic substrates are prone to electrostatic discharge (ESD) damage because plastics are usually associated with the generation of electrostatic charge. By contrast, the CPI in this present work is ESD-free because localized ESD can be released via the conductive CNT. In their experiments, the team rolled the TFT devices 100 times on a cylinder with radius of 4 mm, without significantly degrading their performance. Integrated circuits also operated without degradation, while being bent to a radius of 2 mm, making these devices suitable for transparent and rollable displays. Source: Nanowerk (http://www.nanowerk.com/spotlight/spotid=38815.php)

Nanowire clothing could keep people warm — without heating everything else

National Nanomanufacturing Network - January 29, 2015 - 8:49am
To stay warm when temperatures drop outside, we heat our indoor spaces — even when no one is in them. But scientists have now developed a novel nanowire coating for clothes that can both generate heat and trap the heat from our bodies better than regular clothes. They report on their technology, which could help us reduce our reliance on conventional energy sources, in the ACS journal Nano Letters ("Personal Thermal Management by Metallic Nanowire-Coated Textile" (http://dx.doi.org/doi:10.1021/nl5036572)). Yi Cui and colleagues note that nearly half of global energy consumption goes toward heating buildings and homes. But this comfort comes with a considerable environmental cost – it's responsible for up to a third of the world's total greenhouse gas emissions. Scientists and policymakers have tried to reduce the impact of indoor heating by improving insulation and construction materials to keep fuel-generated warmth inside. Cui's team wanted to take a different approach and focus on people rather than spaces. The researchers developed lightweight, breathable mesh materials that are flexible enough to coat normal clothes. When compared to regular clothing material, the special nanowire cloth trapped body heat far more effectively. Because the coatings are made out of conductive materials, they can also be actively warmed with an electricity source to further crank up the heat. The researchers calculated that their thermal textiles could save about 1,000 kilowatt hours per person every year — that's about how much electricity an average U.S. home consumes in one month. Source: American Chemical Society (http://www.acs.org/content/acs/en/pressroom/presspacs/2015/acs-presspac-january-28-2015/nanowire-clothing-could-keep-people-warm-without-heating-everything-else.html)

Wearable Sensor Smooths Path to Long-Term EKG, EMG Monitoring

National Nanomanufacturing Network - January 22, 2015 - 6:26am
Researchers from North Carolina State University have developed a new, wearable sensor that uses silver nanowires to monitor electrophysiological signals, such as electrocardiography (EKG) or electromyography (EMG). The new sensor is as accurate as the “wet electrode” sensors used in hospitals, but can be used for long-term monitoring and is more accurate than existing sensors when a patient is moving. Long-term monitoring of electrophysiological signals can be used to track patient health or assist in medical research, and may also be used in the development of new powered prosthetics that respond to a patient’s muscular signals. Electrophysiological sensors used in hospitals, such as EKGs, use wet electrodes that rely on an electrolytic gel between the sensor and the patient’s skin to improve the sensor’s ability to pick up the body’s electrical signals. However, this technology poses problems for long-term monitoring, because the gel dries up – irritating the patient’s skin and making the sensor less accurate. The new nanowire sensor is comparable to the wet sensors in terms of signal quality, but is a “dry” electrode – it doesn’t use a gel layer, so doesn’t pose the same problems that wet sensors do. “People have developed other dry electrodes in the past few years, and some have demonstrated the potential to rival the wet electrodes, but our new electrode has better signal quality than most – if not all – of the existing dry electrodes. It is more accurate,” says Dr. Yong Zhu, an associate professor of mechanical and aerospace engineering at NC State and senior author of a paper describing the work. “In addition, our electrode is mechanically robust, because the nanowires are inlaid in the polymer.” The sensors stem from Zhu’s earlier work to create highly conductive and elastic conductors (https://news.ncsu.edu/2012/07/wms-zhu-silver-stretch/) made from silver nanowires, and consist of one layer of nanowires in a stretchable polymer. The new sensor is also more accurate than existing technologies at monitoring electrophysiological signals when a patient is in motion. “The silver nanowire sensors conform to a patient’s skin, creating close contact,” Zhu says. “And, because the nanowires are so flexible, the sensor maintains that close contact even when the patient moves. The nanowires are also highly conductive, which is key to the high signal quality.” The new sensors are also compatible with standard EKG- and EMG-reading devices. “I think these sensors are essentially ready for use,” Zhu says “The raw materials of the sensor are comparable in cost to existing wet sensors, but we are still exploring ways of improving the manufacturing process to reduce the overall cost.” An uncorrected proof of the paper, “Wearable Silver Nanowire Dry Electrodes for Electrophysiological Sensing (http://pubs.rsc.org/en/content/articlelanding/2015/ra/c4ra15101a#%21divAbstract),” was published online Jan. 14 in RSC Advances, immediately after acceptance. Lead author of the paper is Amanda Myers, a Ph.D. student at NC State. The paper was co-authored by Dr. Helen Huang, an associate professor in the joint biomedical engineering program at NC State and the University of North Carolina at Chapel Hill.Source: North Carolina State University

NanoSphere Health Sciences Announces Patent-Pending Status for Nanoparticle Encapsulation of NSAIDs

National Nanomanufacturing Network - January 16, 2015 - 3:19am
NanoSphere Health Sciences, LLC, innovative developers of the industry-first, patent-pending NanoSphere™ delivery system, announced today that the U.S. Patent and Trademark office issued "Patent Pending" status for its new NSAID NanoSphere technology platform. NanoSphere Health's NSAIDs are the first to encapsulate prescription and over-the-counter (OTC) NSAIDs (non-steroidal anti-inflammatory drugs such as Ibuprofen, Aspirin, Naproxen, etc.) as a method to treat and prevent inflammatory disorders and global inflammation and pain. The use of the NanoSphere delivery technology eliminates and alleviates many of the severe side effects NSAIDs can have, such as stomach irritation, stomach bleeding and GI bleeding, among others. At the same time, it increases the therapeutic activity of NSAIDs for safe, long-term and more effective therapy. NanoSphere NSAIDs are uniquely designed to be administered intraorally, intranasally and transdermally. The convenient liquid nanogels bypass the GI tract avoiding gastrointestinal irritation. When taken perorally, NanoSphere NSAIDs' structure of purified essential phospholipids maintains the protective GI tract mucosa barrier from damage by NSAIDs. The NanoSphere NSAIDs are then efficiently transported into the circulatory system for greater therapeutic activity in safely treating inflammatory conditions and relieving pain. "We are excited to announce that NanoSphere's NSAID technology platform has achieved a 'Patent Pending' status, protecting the intellectual property of our NanoSphere delivery system within NSAIDs," said Dr. Richard Kaufman, Chief Science Officer at NanoSphere Health Sciences. "Our disruptive NanoSphere delivery biotechnology introduces a significant advancement in the therapeutic potential and safety of OTC and prescription NSAIDs along with a tremendous growth potential." NSAIDs cause a range of gastrointestinal problems from mild upset stomach to serious conditions such as stomach bleeding, ulcers and kidney damage, factors which often limit their use. Among patients using NSAIDs, 30-40% have some degree of GI intolerance. NSAIDs physically damage the protective GI mucosa surface and promote bleeding. Furthermore, NSAIDs are fat-soluble drugs with low solubility and dissolution in water. This makes OTC and prescription NSAID pills hard to absorb and contributes to their causing GI problems. "The problems with current NSAID therapy are glaringly apparent," says Terry Grossman M.D., Medical Director at NanoSphere Health Sciences. "NSAIDs have low bioavailability and limited delivery into inflamed areas. They produce adverse effects, compounded with the fact that nearly half the population has difficulties swallowing currently sold NSAID pills and capsules." The company's patent-pending phospholipid nanoparticle encapsulation of NSAIDs technology provides the following potential benefits: Higher Concentration of NSAIDs Increased Bioavailability of NSAIDs (2-fold to 10-fold) Decreased Dosage of NSAIDS (2-fold to 10-fold) Enables Safe, Long-Term Use and More Efficacious NSAID Therapy and Treatment Reduced Risk of Gastrointestinal Problems Transport into and Targeting of Specific Body Sites Delivery into the Central Nervous System Enhanced Therapeutic Value Ideal for Long-Term and Daily Use NanoSphere Health expects availability of commercial licensing by the second quarter of 2015, after clinical trials have been completed. About NanoSphere Health Sciences, LLC With its headquarters in Denver, Colorado, NanoSphere Health Sciences is a biotechnology firm specializing in the creation of NanoSphere delivery systems for the supplement, nutraceutical, OTC and pharmaceutical industries. For more information, visit www.nanospherehealth.com (http://www.nanospherehealth.com) Source: NanoSphere Health Sciences

TechConnect World/Nanotech 2015 - Technical Call for Papers

National Nanomanufacturing Network - January 13, 2015 - 4:17am
TechConnect World/Nanotech 2015 - Conference and ExpoJune14-17, 2015Washington, DC Final Call for Abstracts Innovations - Friday Jan. 16 Nanotech 2015/TechConnect World Innovation Conference June 14-17, 2015 - Washington DCFor an InterNano supporting partnership 10% discount on registration (http://www.techconnectworld.com/World2015/register.html) enter our code: INANO10 Abstract submission will close on Friday, January 16, for the TechConnect World Innovation Conference, June 14-17, Gaylord Convention Center, Washington DC, USA. On behalf of our symposium organizers we warmly invite you to submit your research abstract and participate in this exciting international event. How to Participate: Submit Your Abstract - due January 16th Submit your technical research and development innovations for review and consideration for podium or poster presentation. Submit Your Innovation - due January 30th We are looking for breakthrough technologies that are ready for licensing, corporate partnering, or investment opportunities. Innovators and Prospectors Include: All U.S. Funding AgenciesAll U.S. National Labs Top-tier Academic Innovators State Country Innovation Delegations • Global Corporate Innovation Prospectors For further information, please visit: http://www.techconnectworld.com/World2015/ (http://www.techconnectworld.com/World2015/)Authors of research submissions, upon acceptance, registration (http://www.techconnectworld.com/World2015/register.html) enter our code: INANO10 About the event: The world’s largest nanotechnology event, Nanotech 2015, delivers application-focused research from the top international academic, government and private industry labs. Thousands of leading researchers, scientists, engineers and technology developers participate in Nanotech to identify new technology trends, development tools, product opportunities, R D collaborations, and commercialization partners. Join the global community that has been working together for over 17 years to integrate nanotechnology into industry with a focus on scale, safety and cost-effectiveness.The joint TechConnect World and the National Innovation Summit is uniquely designed to accelerate the commercialization of innovations, out of the lab and into industry. TechConnect World is divided into a Technical Research Program and an Innovation Partnering Program, gathering the world's leading market-focused research and commercially-viable innovations into the largest global technology accelerator program.

"Global Leadership and Service Award" of the International Union of Materials ...

National Nanomanufacturing Network - January 9, 2015 - 4:32am
The IUMRS Global Leadership and Service Award for 2015 will be awarded to Dr. Mihail Roco, Mr. Christos Tokamanis, and Dr. Paul Siffert at a ceremony to be held at the European Parliament on Monday, 23rd February 2015 For 2015, the Award honors very distinguished individuals who have demonstrated outstanding leadership through services having measurable impact in the fields of Nanotechnology and materials for the global community: Professor Doctor Mihail Roco, the founding Chair of the National Science and Technology Council's subcommittee on Nanoscale Science, Engineering and Technology of USA National Science Foundation, for his extra-ordinary services in the area of Nanotechnology with significant impact in the USA and around the world. Mr. Christos Tokamanis, head of Unit "Advanced Materials and Nano Technologies" - Directorate "Key Enabling Technologies, Research Innovation", European Commission, for the outstanding services to the European Union community in supporting an effective and efficient nanotechnology policy integrating the needs of innovation with societal impact and responsible governance. Professor Doctor Paul Siffert, founder and First President of the "European Materials Research, Society" (E-MRS); General Secretary of the "European Materials Forum" (EMF) and of the "European Materials Research Society" (E-MRS), Czochralski Gold Medal, and for 30 years of dedicated services to European and Global Materials Community. The IUMRS has a mission of supporting excellence in materials research and education, and development of future leaders to work together for a world that has critical needs in order to sustain itself. Accordingly, to promote this mission, IUMRS announced the Global Leadership and Service Award. This Award will be given to individuals who have demonstrated outstanding leadership through service having measurable impact to the global community, relating to materials research and education. Source: IUMRS (http://www.iumrshq.org/attachments/197_Poster_Global_Awards_%281%29-final2-.pdf)

New webinar series focuses on the experiences of nanotechnology businesses

National Nanomanufacturing Network - January 9, 2015 - 4:10am
Webinar 1: Roadblocks to Success in Nanotechnology Commercialization – What Keeps the Small and Medium Enterprise Community Up at Night? What: The NNCO will hold a series of webinars focusing on the experiences, successes, and challenges for small- and medium-sized businesses working in nanotechnology and on issues of interest to the business community. The first webinar is “Roadblocks to Success in Nanotechnology Commercialization – What Keeps the Small and Medium Enterprise Community Up at Night?” When: The first webinar will be held Thursday, January 15, 2015, from 12:00 p.m. to 1:00 p.m. EST. This webinar will be a round-table discussion with small and medium-sized businesses involved in nanotechnology commercialization focused on understanding common problems that they face and identifying those problems that the NNCO and NSET can assist in overcoming. Who: Craig Bandes, Pixelligent LLC Doyle Edwards, Brewer Science Inc. Scott Rickert, PEN Inc. How: Questions of interest to the small- and medium-sized business community may be submitted to webinar@nnco.nano.gov (mailto:webinar@nnco.nano.gov) beginning one week prior to the event through the close of the webinar. During the question-and-answer segment of the webinars, submitted questions will be considered in the order received and may be posted on the NNI Web site (www.nano.gov (http://www.nano.gov/)). A moderator will identify relevant questions and pose them to the panelists. Due to time constraints, not all questions may be addressed during the webinar. The moderator reserves the right to group similar questions and to skip questions, as appropriate. Registration: Click here to register for this free, online event. (https://events-na12.adobeconnect.com/content/connect/c1/1305935587/en/events/event/shared/default_template/event_registration.html?sco-id=1309829163 _charset_=utf-8) Registration for the webinar is required and is on a first-come, first-served basis and will be capped at 200 participants. Source: NNCO (http://www.nano.gov/SMEwebinars2015)