InterNano Nanomanufacturing Repository
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Non-Euclidean Geometry of Twisted Filament Bundle Packing
No full textDensely packed and twisted assemblies of filaments are crucial structural motifs in macroscopic materials (cables, ropes, and textiles) as well as synthetic and biological nanomaterials (fibrous proteins). We study the unique and nontrivial packing geometry of this universal material design from two perspectives. First, we show that the problem of twisted bundle packing can be mapped exactly onto the problem of disc packing on a curved surface, the geometry of which has a positive, spherical curvature close to the center of rotation and approaches the intrinsically flat geometry of a cylinder far from the bundle center. From this mapping, we find the packing of any twisted bundle is geometrically frustrated, as it makes the sixfold geometry of filament close packing impossible at the core of the fiber. This geometrical equivalence leads to a spectrum of close-packed fiber geometries, whose low symmetry (five-, four-, three-, and twofold) reflect non-Euclidean packing constraints at the bundle core. Second, we explore the ground-state structure of twisted filament assemblies formed under the influence of adhesive interactions by a computational model. Here, we find that the underlying non-Euclidean geometry of twisted fiber packing disrupts the regular lattice packing of filaments above a critical radius, proportional to the helical pitch. Above this critical radius, the ground-state packing includes the presence of between one and six excess fivefold disclinations in the cross-sectional order
Graphene-Supported Pt, Ir and Pt-Ir Nanoparticles as Electrocatalysts for the Oxidation of Ammonia
No full textCharge Carrier Transport and Digital Data Transmission Performance In Sub-20 nm Diameter Indium Antimonide Nanowires
No full textFastTrack: Toward Nanoscale Fault Masking With High Performance
No full textHigh defect rates are associated with novel nanodevice-based systems owing to unconventional and self-assembly-based manufacturing processes. Furthermore, in emerging nanosystems, fault mechanisms and distributions may be very different from CMOS due to unique physical layer aspects, and emerging circuits and logic styles. Development of analytical fault models for nanosystems is necessary to explore the design of novel fault tolerance schemes that could be more effective than conventional schemes. In this paper, we first develop a detailed analytical fault model for the nanoscale application specific integrated circuits (NASIC) computing fabric and show that the probability of 0-to-1 faults is much higher than of 1-to-0 faults. We then show that in fabrics with unequal fault probabilities, using biased voting schemes, as opposed to conventional majority voting, could provide better yield. However, due to the high defect rates, voting will need to be combined with more fine-grained structural redundancy for acceptable yield. This entails degradation in performance (operating frequency) due to an increase in circuit fan-in and fan-out. We, therefore, introduce a new class of redundancy schemes called FastTrack that combine nonuniform structural redundancy with uniquely biased nanoscale voters to achieve greater yield without a commensurate loss in performance. A variety of such techniques are employed on a wire streaming processor (WISP-0) implemented on the NASIC fabric. We show that FastTrack schemes can provide 23% higher effective yield than conventional redundancy schemes even at 10% defect rates along with 79% lesser performance degradation
Triisopropylsilylethynyl-functionalized dibenzo[def,mno]chrysene: a solution-processed small molecule for bulk heterojunction solar cells
No full textThis communication reports the synthesis of a new polycyclic aromatic hydrocarbon and its unique packing motif. This molecule is shown to be an efficient electron donor in organic bulk heterojunction solar cells, exhibiting a power conversion efficiency of [similar]2.0%
Roll-to-Roll Nanoimprint Test Bed
No full textThe CHM has initiated a new roll-to-roll system-level test bed program to facilitate the development of a manufacturing platform for fabrication of low-cost, large-area nano-materials and devices using roll-to-roll processing technology. This rollto-roll process test bed was developed to address the challenge of fabricating nanostructured thin films on a high-speed, high-reliability platform. Moving forward, this test bed will enable low-cost commercialization of nanotechnology in applications ranging water purification & filtration, batteries and thin film organic-based photovoltaics. The center accepted delivery of the first custom roll-to-roll nanoimprint lithography (R2RNIL) tool in June 2011. Center researchers are now routinely printing sub-200 nm features in a continuous web process. Center researchers are currently developing new materials and processes to enable printing of features to the ten’s of nanometers. Understanding flow and rheological properties is critical to the mission. Real-time inspection and metrology capabilities are being developed for the new tools
Case Studies in Nanomanufacturing Commercialization Through Effective Partnerships and Technology Transfer: Rolith Corporation
No full textWith the increased emphasis towards nanomanufacturing and commercialization of nanotechnology-enabled products, one key challenge is enhancing the innovation cycle. Through the innovation cycle, fundamental discoveries in the nanosciences are translated to applications and product scale-up. As many start-up or small company innovators are resource limited, the strategy of establishing strong partnerships with academic institutions and researchers provides a very effective path to extended R&D activities. Such partnerships typically lead to intellectual property, licensing, and technology transfer that enhance the cultures of academic researchers and small businesses alike, both in providing new perspectives for each into the innovation cycle, as well as accelerating the time and path to commercialization. A recent prime example of this scenario combines innovations emerging from collaborations between an academic institution and a small business start-up.
Also included: The View From the Nano Trenches, Santa, Bring Me Nanotech, and Nanotechnology in the Cement Industry - A Patent Analysi
