Feed aggregator

Nanosensor Arrays Enable Highly Sensitive Chemical Fingerprinting for Explosive Detection

National Nanomanufacturing Network - July 31, 2014 - 3:30am
Reliable detection of trace amounts of hazardous chemicals, in particular explosives, remains a pervasive problem due to the broad variety of associated chemical compounds that must be monitored in an open environment. In combination with the inherently low vapor pressures of most explosive compounds, the challenges of detecting potential threats require sensing techniques having ultra-high sensitivity, high selectivity, and rapid response. While such performance is available using sophisticated and expensive equipment, the need exists for portable, low cost systems that can discriminate a broad range of chemical species with high sensitivity and low probability of false responses. A broad range of nanomaterials have proven effective for chem/bio detection due to their high surface to volume ratio, thereby providing high sensitivity. Effective probability of detection has been demonstrated for certain trace chemical analysis by chemically functionalizing the nanomaterial surface such that the analyte of interest has an increased affinity to bind with the nanomaterial surface, which changes the electrical properties of the sensor. While this has enabled a pathway for highly sensitive, low cost sensor platforms, chemical selectivity for detection in open environments remains a challenge. For this, the concept of a chemical nose is required that can accurately discriminate trace chemicals in air. Approaches to chemical nose sensing typically include arrays of nanosensors with different elements of the array having variable properties for binding different chemical species by varying the chemical functionality added to the individual sensors in the array. Subsequent statistical analysis of the sensor array when exposed to various compounds can then provide a specific signature associated with each compound. Establishing a library of signatures makes this approach extendable for identification of a broad range of chemical unknowns. Recently, Lichtenstein, et. al. reported on the demonstration of a chemically modified nanosensor array platform for ultrasensitive detection of explosives (http://www.nature.com/ncomms/2014/140624/ncomms5195/full/ncomms5195.html) . The reported platform consisted of 144 nanosensors arranged into 8 subarrays of 18 nanosensors. Each nanosensor element consisted of a silicon nanowire Field Effect Transistor (FET) device, with each subarray chemically modified with different small molecule receptors for ultrasensitive discrimination of chemical species. Each subarray is fed by a microfluidic channel which controls the flow and interaction of the analyte with the modified sensor array. Detection occurs by first sampling the air for 5 seconds, which is pre-concentrated by flowing through a microporous filter (50-100 l/min), then flushing the adsorbed analyte from the filter membrane using a commercially available explosive standard solution, which subsequently carries the analyte to the nanosensor subarrays. Characterization of the chemical nose platform for a range of explosive compounds demonstrated unprecedented sensitivity in the parts per quadrillion (10-15) range. More importantly, the implementation of real time mathematical analysis, kinetically and thermodynamically, of the nanosensor array elements enables discrimination and identification of numerous explosive materials with standoff distance up to several meters, including non-nitrogen containing compounds. This demonstration provides a prominent example of a nano-enabled system with unprecedented performance solving a critical problem. Further development and application of surface modification chemistries and regeneration of nanosensor surfaces will impact a much broader range of applications in chemical identification and healthcare assessment. References: Lichtenstein A, Havivi E, Shacham R, Hahamy E, Leibovich R, Pevzner A, Krivitsky V, Davivi G, Presman I, Elnathan R, Engel Y, Flaxer E, Patolsky F. Supersensitive fingerprinting of explosives by chemically modified nanosensors arrays. Nat. Commun. 5(4195). doi: 10.1038/ncomms5195 (http://www.nature.com/ncomms/2014/140624/ncomms5195/full/ncomms5195.html) Image reprinted with permission from Nature Publishing Group.

Watching Schrödinger's cat die (or come to life): Steering quantum evolution & using probes to conduct continuous error correction in quantum computers

Nanotech-Now - July 30, 2014 - 6:06pm
One of the famous examples of the weirdness of quantum mechanics is the paradox of Schrödinger's cat. If you put a cat inside an opaque box and make his life dependent on a random event, when does...
Categories: Nanotechnology News

From Narrow to Broad

Nanotech-Now - July 30, 2014 - 6:06pm
Electromagnetic absorbers based on plasmonic and metamaterial structures are of great interest for many areas as narrowband absorbers. A variety of approaches have been proposed to achieve broadband a...
Categories: Nanotechnology News

FLAG-ERA and TNT2014 join efforts: Graphene Networking at its higher level in Barcelona: Encourage the participation in a joint transnational call

Nanotech-Now - July 30, 2014 - 6:06pm
On the occasion of the TNT2014 International Conference, a Graphene Networking Event organized by FLAG-ERA will take place in Barcelona, the 27th of October.
Categories: Nanotechnology News

New Objective Focusing Nanopositioner from nPoint

Nanotech-Now - July 30, 2014 - 6:06pm
The nPFocus1000 is the latest addition to nPoint's nanopositioning lineup. This new piezo stage is designed to position an objective lens over 1000 µm with speed and accuracy.
Categories: Nanotechnology News

University of Manchester selects Anasys AFM-IR for coatings and corrosion research

Nanotech-Now - July 30, 2014 - 6:06pm
Anasys Instruments reports on the recent installation of an AFM-IR system at the Corrosion & Protection Centre, part of the School of Materials at the University of Manchester for use by the group of...
Categories: Nanotechnology News

Nature inspires a greener way to make colorful plastics

Nanotech-Now - July 30, 2014 - 6:06pm
Long before humans figured out how to create colors, nature had already perfected the process — think stunning, bright butterfly wings of many different hues, for example. Now scientists are tapping i...
Categories: Nanotechnology News

Analytical solutions from Malvern Instruments support University of Wisconsin-Milwaukee researchers in understanding environmental effects of nanomaterials

Nanotech-Now - July 30, 2014 - 6:06pm
Researchers at The School of Freshwater Science, University of Wisconsin-Milwaukee, USA, are using NanoSight Nanoparticle Tracking Analysis (NTA) from Malvern Instruments to investigate the effects of...
Categories: Nanotechnology News

FEI Unveils New Solutions for Faster Time-to-Analysis in Metals Research

Nanotech-Now - July 30, 2014 - 6:06pm
New Helios DualBeam uses a plasma focused ion beam for high-throughput milling, while the new Teneo scanning electron microscope provides high-resolution, high-contrast images and fast, precise analyt...
Categories: Nanotechnology News

Terabyte Photonic Dataset Sale

Nanotech-Now - July 30, 2014 - 6:06pm
A whole terabyte dataset of various photonic crystal style geometric structures is open for view and purchase.
Categories: Nanotechnology News

SouthWest NanoTechnologies Names NanoSperse as A SWeNT Certified Compounder

Nanotech-Now - July 30, 2014 - 6:06pm
SouthWest NanoTechnologies (SWeNT) announced today that it has named NanoSperse, Inc. in Kettering, Ohio, as a "SWeNT Certified Compounder" for its line of SMWTM Specialty Multi-Wall Carbon Nanotubes...
Categories: Nanotechnology News

Graphene Networking Event

InterNano - Upcoming Events - July 30, 2014 - 11:51am
October 27, 2014 - On the occasion of the TNT2014 International Conference, a Graphene Networking Event organized by FLAG-ERA will take place in Barcelona, the 27th of October.FLAG-ERA is a FP7 ERA-NET that gathers most regional and national funding organisations (NRFOs) in Europe with the goal of supporting the Future and Emerging Technologies (FET) Flagship concept and more specifically, the FET Flagship initiatives Graphene and Human Brain Project (HBP).FLAG-ERA will launch a joint transnational call (JTC) enabling researchers from different countries to propose joint contributions to the Flagships. In order to encourage and facilitate the participation in the JTC, FLAG-ERA organises networking events for stakeholders from basic and applied research and innovation.The FLAG-ERA Graphene Networking Event intents to bring together stakeholders in the area of graphene, taking advantage of the presence of a considerable group of researchers, industry and the Graphene Flagship itself in the TNT conference.

Graphene one-day Symposium

InterNano - Upcoming Events - July 30, 2014 - 11:50am
October 28, 2014 - On the occasion of TNT2014, the 15th edition of the Trends in Nanotechnology International Conference (TNT 2014), a Graphene one-day Symposium will be organized in Barcelona (Spain) at Auditorium - ONCE Catalunya. This one-day event will be organized in collaboration with ICN2 (Spain) and will take place on October 28. The Graphene Day entails a plenary session during the morning and the afternoon session will be divided in track A (Graphene science driven) and track B (Graphene driven applications).

Magnetite self-assembly: competition yields surprises

Nanotechweb - July 30, 2014 - 10:46am
Nanocrystals of magnetite self-assemble in the presence of competing van der Waals and magnetic forces into previously unseen helical structures.
Categories: Nanotechnology News

Lasing plasmon nanocavity detects deadly explosives

Nanotechweb - July 30, 2014 - 8:08am
New device might be used in applications such as security screening at airports and in biosensing.
Categories: Nanotechnology News

JSNN nanomanufacturing group adds members

National Nanomanufacturing Network - July 30, 2014 - 3:41am
An organization established by the Joint School of Nanoscience and Nanoengineering (http://jsnn.ncat.uncg.edu/) and Gateway University Research Park (http://www.gatewayurp.com/) in Greensboro to build partnerships between academic researchers and industry has grown to 25 members in its first year, according to an update from the JSNN. The Nanomanufacturing Innovation Consortium was formed (http://www.bizjournals.com/triad/print-edition/2013/07/26/triad-companies-jsnn-join-forces-with.html?page=2) in July 2013 with an initial group of members that included RF Micro Devices (http://www.rfmd.com/), Syngenta (http://www.syngenta-us.com/home.aspx) and VF Jeanswear among others. Members pay a fee to join the NIC and in return gain access to the JSNN’s cutting-edge equipment as well as access to ideas and expertise from the school’s scientists. Other companies have joined since including (http://www.bizjournals.com/triad/blog/2013/12/itgs-cone-denim-burlington.html) International Textile Group’s (http://www.itg-global.com/) Cone Denim and Burlington divisions, Callaway Carbons, Horiba and AxNano. The 25th member of the group and the most recent to join is Luna Innovations (NASDAQ: LUNA), a Roanoke company that makes fiber optic tools for the telecommunications, aerospace, automotive, energy and defense industries. Cone Denim’s Tom Tantillo (http://www.bizjournals.com/triad/search/results?q=Tom%20Tantillo) said his company is already seeing benefits from its first few months as part of the NIC. “This is proving to be an invaluable resource to our organic growth as well as our market competitiveness,” he said. “Having access to the robust tool set and knowledge base at the JSNN gives us an unprecedented competitive edge in certifying that the technical metrics of a newly engineered product will meet consumer performance expectations.” “The development of strong industry relationships is critical to the success of the Joint School of Nanoscience and Nanoengineering,” said James Ryan (http://www.bizjournals.com/triad/search/results?q=James%20Ryan), founding dean of the school, which is a partnership of N.C. A T State University (http://www.ncat.edu/) and UNC-Greensboro (http://www.uncg.edu/). “JSNN continues to benefit from the leadership and vision of member companies, and we look forward to growing the NIC and continuing collaborations with our partners.”Source: Triad Business Journal

Researchers achieve 'holy grail' of battery design: A stable lithium anode

National Nanomanufacturing Network - July 30, 2014 - 3:31am
The development could lead to smaller, cheaper and more efficient rechargeable batteries. Engineers across the globe have been racing to design smaller, cheaper and more efficient rechargeable batteries to meet the power storage needs of everything from handheld gadgets to electric cars. In a paper (http://www.nature.com/nnano/journal/vaop/ncurrent/full/nnano.2014.152.html) published today in the journal Nature Nanotechnology, researchers at Stanford University report that they have taken a big step toward accomplishing what battery designers have been trying to do for decades – design a pure lithium anode. All batteries have three basic components: an electrolyte to provide electrons, an anode to discharge those electrons and a cathode to receive them. Today, we say we have lithium batteries, but that is only partly true. What we have are lithium ion batteries. The lithium is in the electrolyte but not in the anode. An anode of pure lithium would be a huge boost to battery efficiency. “Of all the materials that one might use in an anode, lithium has the greatest potential. Some call it the Holy Grail,” said Yi Cui (http://profiles.stanford.edu/yi-cui), a professor of Materials Science and Engineering (http://mse.stanford.edu/) and leader of the research team. “It is very lightweight, and it has the highest energy density. You get more power per volume and weight, leading to lighter, smaller batteries with more power.” But engineers have long tried and failed to reach this Holy Grail. “Lithium has major challenges that have made its use in anodes difficult. Many engineers had given up the search, but we found a way to protect the lithium from the problems that have plagued it for so long,” said Guangyuan Zheng, a doctoral candidate in Cui’s lab and first author of the paper. In addition to Cui and Zheng, the research team includes Steven Chu (http://physics.stanford.edu/people/faculty/steven-chu), the former U.S. Secretary of Energy and Nobel Laureate who recently resumed his professorship at Stanford. “In practical terms, if we can triple the energy density and simultaneously decrease the cost four-fold, that would be very exciting. We would have a cell phone with triple the battery life and an electric vehicle with a 300 mile range that cost $25,000 – and with better performance than an internal combustion engine car getting 40 mpg,” Chu said. The engineering challenge In the paper, the authors explain how they are overcoming the problems posed by lithium. Most lithium ion batteries, like those you might find in your smart phone or hybrid car, work similarly. The key components include an anode, the negative pole from which electrons flow out and into a power-hungry device, and the cathode, where the electrons re-enter the battery once they have traveled through the circuit. Separating them is an electrolyte, a solid or liquid loaded with positively charged lithium ions that travel between the anode and cathode. During charging, the positively charged lithium ions in the electrolyte are attracted to the negatively charged anode, and the lithium accumulates on the anode. Today, the anode in a lithium ion battery is actually made of graphite or silicon.Engineers would like to use lithium for the anode, but so far they have been unable to do so. That’s because the lithium ions expand as they gather on the anode during charging. All anode materials, including graphite and silicon, expand somewhat during charging, but not like lithium. Researchers say that lithium’s expansion during charging is “virtually infinite” relative to the other materials. Its expansion is also uneven, causing pits and cracks to form in the outer surface, like paint on the exterior of a balloon that is being inflated. The resulting fissures on the surface of the anode allow the precious lithium ions to escape, forming hair-like or mossy growths, called dendrites. Dendrites, in turn, short circuit the battery and shorten its life. Preventing this buildup is the first challenge of using lithium for the battery’s anode. The second engineering challenge involves finding a way to deal with the fact that lithium anodes are highly chemically reactive with the electrolyte. It uses up the electrolyte and reduces battery life. An additional problem is that the anode and electrolyte produce heat when they come into contact. Lithium batteries, including those in use today, can overheat to the point of fire, or even explosion. They are, therefore, a serious safety concern. The recent battery fires in Tesla cars and on Boeing’s Dreamliner are prominent examples of the challenges of lithium ion batteries. Building the nanospheres To solve these problems the Stanford researchers built a protective layer of interconnected carbon domes on top of their lithium anode. This layer is what the team has called nanospheres. The Stanford team’s nanosphere layer resembles a honeycomb: it creates a flexible, uniform and non-reactive film that protects the unstable lithium from the drawbacks that have made it such a challenge. The carbon nanosphere wall is just 20 nanometers thick. It would take about 5,000 layers stacked one atop another to equal the width of single human hair. “The ideal protective layer for a lithium metal anode needs to be chemically stable to protect against the chemical reactions with the electrolyte and mechanically strong to withstand the expansion of the lithium during charge,” said Cui, who is a member of the Stanford Institute for Materials and Energy Sciences at SLAC National Accelerator Laboratory. The Stanford nanosphere layer is just that. It is made of amorphous carbon, which is chemically stable, yet strong and flexible so as to move freely up and down with the lithium as it expands and contracts during the battery’s normal charge-discharge cycle. Ideal within reach In technical terms, the nanospheres improve the coulombic efficiency of the battery – a ratio of the amount of lithium that can be extracted from the anode when the battery is in use compared with the amount put in during charging. A single round of this give-and-take process is called a cycle. Generally, to be commercially viable, a battery must have a coulombic efficiency of 99.9 percent or more, ideally over as many cycles as possible. Previous anodes of unprotected lithium metal achieved approximately 96 percent efficiency, which dropped to less than 50 percent in just 100 cycles—not nearly good enough. The Stanford team’s new lithium metal anode achieves 99 percent efficiency even at 150 cycles. “The difference between 99 percent and 96 percent, in battery terms, is huge. So, while we’re not quite to that 99.9 percent threshold, where we need to be, we’re close. And this is a significant improvement over any previous design,” Cui said. “With some additional engineering and new electrolytes, we believe we can realize a practical and stable lithium metal anode that could power the next generation of rechargeable batteries.”Source: Stanford School of Engineering (https://engineering.stanford.edu/news/stanford-team-achieves-holy-grail-battery-design-stable-lithium-anode)Image reprinted with permission from Interconnected hollow carbon nanospheres for stable lithium metal anodes ; Guangyuan Zheng, Seok Woo Lee, Zheng Liang, Hyun-Wook Lee, Kai Yan, Hongbin Yao; Nature Nanotechnology 2014.

Seeing is bead-lieving: Rice University scientists create model 'bead-spring' chains with tunable properties

Nanotech-Now - July 29, 2014 - 7:45am
Rice University researchers are using magnetic beads and DNA "springs" to create chains of varying flexibility that can be used as microscale models for polymer macromolecules.
Categories: Nanotechnology News

Measuring the Smallest Magnets

Nanotech-Now - July 29, 2014 - 7:45am
Imagine trying to measure a tennis ball that bounces wildly, every time to a distance a million times its own size. The bouncing obviously creates enormous "background noise" that interferes with the...
Categories: Nanotechnology News

WITec to host the 11th Confocal Raman Imaging Symposium from September 29th - October 1st in Ulm, Germany

Nanotech-Now - July 29, 2014 - 7:45am
The 11th confocal Raman Imaging Symposium will be held from September 29th - October 1st in Ulm, Germany. The well-established, annual symposium will cover various aspects of modern Raman microscopy a...
Categories: Nanotechnology News