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Full-Text Articles in Nanoscience and Nanotechnology

Cementitious Sensors Exhibiting Stopbands In Acoustic Transmission Spectra, Shreya Vemuganti Nov 2018

Cementitious Sensors Exhibiting Stopbands In Acoustic Transmission Spectra, Shreya Vemuganti

Shared Knowledge Conference

Ultrasonic monitoring in cementitious materials is challenging due to the high degree of attenuation. In wellbore environments, monitoring becomes more challenging due to inaccessibility. Meta materials, also known as acoustic bandgap materials, exhibit an interesting feature of forbidding the propagation of elastic/sound waves and isolate vibration in a certain frequency band. Traditionally, acoustic bandgap materials are developed with inclusions such as tin, aluminum, gold, steel in a polymer matrix. In this study, we present the development of three-dimensional cementitious sensors capable of exhibiting stopbands in the acoustic transmission spectra using carbon nanotubes. Relatively wide stopbands were engineered using Floquet-Bloch ...


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 ...


Novel Nanocomposite Clay Brick For Strain Sensing In Structural Masonry, F. Ubertini, A. D'Alessandro, A. L. Materazzi, Simon Laflamme, Austin Downey Feb 2018

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

Simon Laflamme

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 ...


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 Feb 2018

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

Simon Laflamme

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 ...


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 ...