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Articles 1 - 11 of 11

Full-Text Articles in Nanoscience and Nanotechnology

Replica Molding-Based Nanopatterning Of Tribocharge On Elastomer With Application To Electrohydrodynamic Nanolithography, Qiang Li, Akshit Peer, In-Ho Cho, Rana Biswas, Jaeyoun Kim Mar 2018

Replica Molding-Based Nanopatterning Of Tribocharge On Elastomer With Application To Electrohydrodynamic Nanolithography, Qiang Li, Akshit Peer, In-Ho Cho, Rana Biswas, Jaeyoun Kim

Ames Laboratory Accepted Manuscripts

Replica molding often induces tribocharge on elastomers. To date, this phenomenon has been studied only on untextured elastomer surfaces even though replica molding is an effective method for their nanotexturing. Here we show that on elastomer surfaces nanotextured through replica molding the induced tribocharge also becomes patterned at nanoscale in close correlation with the nanotexture. By applying Kelvin probe microscopy, electrohydrodynamic lithography, and electrostatic analysis to our model nanostructure, poly(dimethylsiloxane) nanocup arrays replicated from a polycarbonate nanocone array, we reveal that the induced tribocharge is highly localized within the nanocup, especially around its rim. Through finite element analysis, we ...


An Experimental Study On Static And Dynamic Strain Sensitivity Of Smart Concrete Sensors Doped With Carbon Nanotubes For Shm Of Large Structures, Andrea Meoni, Antonella D'Alessandro, Austin Downey, Enrique García-Macías, Marco Rallini, A. Luigi Materazzi, Luigi Torre, Simon Laflamme, Rafael Castro-Triguero, Filippo Ubertini Jan 2018

An Experimental Study On Static And Dynamic Strain Sensitivity Of Smart Concrete Sensors Doped With Carbon Nanotubes For Shm Of Large Structures, Andrea Meoni, Antonella D'Alessandro, Austin Downey, Enrique García-Macías, Marco Rallini, A. Luigi Materazzi, Luigi Torre, Simon Laflamme, Rafael Castro-Triguero, Filippo Ubertini

Civil, Construction and Environmental Engineering Publications

The availability of new self-sensing cement-based strain sensors allows the development of dense sensor networks for Structural Health Monitoring (SHM) of reinforced concrete structures. These sensors are fabricated by doping cement-matrix materials with conductive fillers, such as Multi Walled Carbon Nanotubes (MWCNTs), and can be embedded into structural elements made of reinforced concrete prior to casting. The strain sensing principle is based on the multifunctional composites outputting a measurable change in their electrical properties when subjected to a deformation. Previous work by the authors was devoted to material fabrication, modeling and applications in SHM. In this paper, we investigate the ...


Damage Detection, Localization And Quantification In Conductive Smart Concrete Structures Using A Resistor Mesh Model, Austin Downey, Antonella D’Alessandro, Micah Baquera, Enrique García-Macías, Daniel Rolfes, Filippo Ubertini, Simon Laflamme, Rafael Castro-Triguero Oct 2017

Damage Detection, Localization And Quantification In Conductive Smart Concrete Structures Using A Resistor Mesh Model, Austin Downey, Antonella D’Alessandro, Micah Baquera, Enrique García-Macías, Daniel Rolfes, Filippo Ubertini, Simon Laflamme, Rafael Castro-Triguero

Civil, Construction and Environmental Engineering Publications

Interest in self-sensing structural materials has grown in recent years due to their potential to enable continuous low-cost monitoring of next-generation smart-structures. The development of cement-based smart sensors appears particularly well suited for structural health monitoring due to their numerous possible field applications, ease of use, and long-term stability. Additionally, cement-based sensors offer a unique opportunity for monitoring of civil concrete structures because of their compatibility with new and existing infrastructure. In this paper, we propose the use of a computationally efficient resistor mesh model to detect, localize and quantify damage in structures constructed from conductive cement composites. The proposed ...


Static And Dynamic Strain Monitoring Of Reinforced Concrete Components Through Embedded Carbon Nanotube Cement-Based Sensors, Antonella D’Alessandro, Filippo Ubertini, Enrique García-Macías, Rafael Castro-Triguero, Austin Downey, Simon Laflamme, Andrea Meoni, Annibale Luigi Materazzi Aug 2017

Static And Dynamic Strain Monitoring Of Reinforced Concrete Components Through Embedded Carbon Nanotube Cement-Based Sensors, Antonella D’Alessandro, Filippo Ubertini, Enrique García-Macías, Rafael Castro-Triguero, Austin Downey, Simon Laflamme, Andrea Meoni, Annibale Luigi Materazzi

Civil, Construction and Environmental Engineering Publications

The paper presents a study on the use of cement-based sensors doped with carbon nanotubes as embedded smart sensors for static and dynamic strain monitoring of reinforced concrete (RC) elements. Such novel sensors can be used for the monitoring of civil infrastructures. Because they are fabricated from a structural material and are easy to utilize, these sensors can be integrated into structural elements for monitoring of different types of constructions during their service life. Despite the scientific attention that such sensors have received in recent years, further research is needed to understand (i) the repeatability and accuracy of sensors’ behavior ...


Novel Nanocomposite Clay Brick For Strain Sensing In Structural Masonry, F. Ubertini, A. D'Alessandro, A. L. Materazzi, Simon Laflamme, Austin Downey Jul 2017

Novel Nanocomposite Clay Brick For Strain Sensing In Structural Masonry, F. Ubertini, A. D'Alessandro, A. L. Materazzi, Simon Laflamme, Austin Downey

Civil, Construction and Environmental Engineering Conference Presentations and Proceedings

The monitoring of civil structures is critical in ensuring users' safety. Structural health monitoring (SHM) is the automation of this monitoring task. It is typically used to identify incipient damages through a spatio-temporal comparison in structural behaviors. Traditional sensors exhibit mechanical characteristics that are usually very different from those of the structures they monitor, which is a factor limiting their durability. Ideally, the material of a sensor would share the same mechanical characteristics as the material onto or into which it is installed. A solution is to fabricate multifunctional materials, capable of serving both structural and sensing functions, also known ...


Enhanced Lumped Circuit Model For Smart Nanocomposite Cement-Based Sensors Under Dynamic Compressive Loading Conditions, Enrique García-Macías, Austin Downey, Antonella D’Alessandro, Rafael Castro-Triguero, Simon Laflamme, Filippo Ubertini Jun 2017

Enhanced Lumped Circuit Model For Smart Nanocomposite Cement-Based Sensors Under Dynamic Compressive Loading Conditions, Enrique García-Macías, Austin Downey, Antonella D’Alessandro, Rafael Castro-Triguero, Simon Laflamme, Filippo Ubertini

Civil, Construction and Environmental Engineering Publications

Smart composite nanostructured materials represent one of the fastest-growing areas of interest among scientists in recent years and, in particular, carbon nanotube (CNT) cement-based composites are attracting more and more attention. These composites exhibit self-sensing capabilities providing measurable variations of their electrical properties under the application of mechanical deformations. Together with this exceptional property, the similarity and compatibility between these composites and structural concrete suggest the possibility of developing distributed embedded strain-sensing systems with substantial improvements in the cost-effectiveness in applications to large-scale concrete structures. In order to design and optimize CNT reinforced cement based dynamic sensors, it is fundamental ...


Continuous And Embedded Solutions For Shm Of Concrete Structures Using Changing Electrical Potential In Self-Sensing Cement-Based Composites, Austin Downey, Enrique Garcia-Macias, Antonella D'Alessandro, Simon Laflamme, Rafael Castro-Triguero, Filippo Ubertini Apr 2017

Continuous And Embedded Solutions For Shm Of Concrete Structures Using Changing Electrical Potential In Self-Sensing Cement-Based Composites, Austin Downey, Enrique Garcia-Macias, Antonella D'Alessandro, Simon Laflamme, Rafael Castro-Triguero, Filippo Ubertini

Civil, Construction and Environmental Engineering Conference Presentations and Proceedings

Interest in the concept of self-sensing structural materials has grown in recent years due to its potential to enable continuous low-cost monitoring of next-generation smart-structures. The development of cement-based smart sensors appears particularly well suited for monitoring applications due to their numerous possible field applications, their ease of use and long-term stability. Additionally, cement-based sensors offer a unique opportunity for structural health monitoring of civil structures because of their compatibility with new or existing infrastructure. Particularly, the addition of conductive carbon nanofillers into a cementitious matrix provides a self-sensing structural material with piezoresistive characteristics sensitive to deformations. The strain-sensing ability ...


Strain Sensitivity Of Carbon Nanotube Cement-Based Composites For Structural Health Monitoring, Antonella D'Alessandro, Filippo Ubertini, Simon Laflamme, Marco Rallini, Josè M. Kenny Apr 2016

Strain Sensitivity Of Carbon Nanotube Cement-Based Composites For Structural Health Monitoring, Antonella D'Alessandro, Filippo Ubertini, Simon Laflamme, Marco Rallini, Josè M. Kenny

Civil, Construction and Environmental Engineering Conference Presentations and Proceedings

Cement-based smart sensors appear particularly suitable for monitoring applications, due to their self-sensing abilities, their ease of use, and their numerous possible field applications. The addition of conductive carbon nanofillers into a cementitious matrix provides the material with piezoresistive characteristics and enhanced sensitivity to mechanical alterations. The strain-sensing ability is achieved by correlating the variation of external loads or deformations with the variation of specific electrical parameters, such as the electrical resistance. Among conductive nanofillers, carbon nanotubes (CNTs) have shown promise for the fabrication of self-monitoring composites. However, some issues related to the filler dispersion and the mix design of ...


Platinum Nanoparticle Decorated Sio2 Microfibers As Catalysts For Micro Unmanned Underwater Vehicle Propulsion, Bolin Chen, Nathaniel T. Garland, Jason Geder, Marius Pruessner, Eric Mootz, Allison Cargill, Anne Leners, Granit Vokshi, Jacob Davis, Wyatt Burns, Michael A. Daniele, Josh Kogot, Igor L. Medintz, Jonathan C. Claussen Jan 2016

Platinum Nanoparticle Decorated Sio2 Microfibers As Catalysts For Micro Unmanned Underwater Vehicle Propulsion, Bolin Chen, Nathaniel T. Garland, Jason Geder, Marius Pruessner, Eric Mootz, Allison Cargill, Anne Leners, Granit Vokshi, Jacob Davis, Wyatt Burns, Michael A. Daniele, Josh Kogot, Igor L. Medintz, Jonathan C. Claussen

Mechanical Engineering Publications

Micro unmanned underwater vehicles (UUVs) need to house propulsion mechanisms that are small in size but sufficiently powerful to deliver on-demand acceleration for tight radius turns, burst-driven docking maneuvers, and low-speed course corrections. Recently, small-scale hydrogen peroxide (H2O2) propulsion mechanisms have shown great promise in delivering pulsatile thrust for such acceleration needs. However, the need for robust, high surface area nanocatalysts that can be manufactured on a large scale for integration into micro UUV reaction chambers is still needed. In this report, a thermal/electrical insulator, silicon oxide (SiO2) microfibers, is used as a support for platinum nanoparticle (PtNP) catalysts ...


Enhanced Polymer Nanocomposites For Condition Assessment Of Wind Turbine Blades, Husaam S. Saleem, M. Thunga, M. Kollosche, Michael R. Kessler, Simon Laflamme Apr 2013

Enhanced Polymer Nanocomposites For Condition Assessment Of Wind Turbine Blades, Husaam S. Saleem, M. Thunga, M. Kollosche, Michael R. Kessler, Simon Laflamme

Civil, Construction and Environmental Engineering Conference Presentations and Proceedings

Damages in composite components of wind turbine blades and large-scale structures can lead to increase in maintenance and repair costs, inoperability, and structural failure. The vast majority of condition assessment of composite structures is conducted by visual inspection and non-destructive evaluation (NDE) techniques. NDE techniques are temporally limited, and may be further impeded by the anisotropy of the composite materials, conductivity of the fibers, and the insulating properties of the matrix. In previous work, the authors have proposed a novel soft elastomeric capacitor (SEC) sensor for monitoring of large surfaces, applicable to composite materials. This soft capacitor is fabricated using ...


Study Of A Nanoscale Water Cluster By Atomic Force Microscopy, Manhee Lee, Baekman Sung, Nicole N. Hashemi, Wonho Jhe Jan 2009

Study Of A Nanoscale Water Cluster By Atomic Force Microscopy, Manhee Lee, Baekman Sung, Nicole N. Hashemi, Wonho Jhe

Nastaran Hashemi

We present a novel method for investigating a nanometric cluster of water molecules, which includes the formation and manipulation of nanometric water, and the measurement of its mechanical properties. The atomic force microscope based on the quartz tuning-fork sensor is employed to form and manipulate the nanometric water, and the theoretical tool of amplitude-modulation atomic force microscopy is used to obtain the elasticity, viscosity and dissipation energy of it. With high vertical resolution less than [similar]0.1 nm and high force sensitivity of [similar]0.01 N m−1, this tool facilitates the stable formation and manipulation of a ...