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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 29 for “"piezoresistivity"”.
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Piezoresistivity Characterization of Polymer Bonded Energetic Nanocomposites under Cyclic Load Cases for Structural Health Monitoring Applications
The strain and damage sensing abilities of randomly oriented multi-walled carbon nanotubes (MWCNTs) dispersed in the polymer binder of energetic composites were experimentally investigated. Ammonium perchlorate (AP) crystals served as the inert energetic and atomized aluminum as the metallic fuel, …
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Computational Micromechanics Analysis of Deformation and Damage Sensing in Carbon Nanotube Based Nanocomposites
… hopping pathways which leads to nanocomposite piezoresistivity is studied in detail along with its evolution under applied deformations. The nanoscale piezoresistive response is used to evaluate macroscale nanocomposite response by using analytical micromechanics methods. The effective …
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Biofidelic Piezoresistive Sandwich Composites
… filler to impart electrical conductivity and piezoresistivity to silicone biofidelic materials. A sandwich structure of silicone and CNT sheet, comprising two dielectric facesheets and a highly conductive core layer has added advantages of raising the dielectric permittivity and suppressing …
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Multiscale Modeling of CNT-Polymer Nanocomposites and Fuzzy Fiber Reinforced Polymer Composites for Strain and Damage Sensing
… may have a substantial influence on the overall piezoresistivity of the nanocomposites, i.e. the electrical tunneling effect and the inherent piezoresistivity of the CNT, are included in microscale RVEs in order to understand their influence on macroscale piezoresistive response in terms of both …
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The Piezoresistive Effect In Microflexures
… bending stresses. A linear model describing piezoresistivity exists for members in pure tension and compression. Extensions of this model to more complex loading conditions do not match experimental results. An accurate model of piezoresistivity in complex loading conditions would expand the …
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Development of a porous piezoresistive material and its applications to underwater pressure sensors and tactile sensors
… occurs during the electromechanical test, the piezoresistivity of this porous PDMS-carbon black composite is reversible and reproducible. Compared to its non-porous counterpart, this porous composite shows a six-times increase in piezoresistivity and a greatly reduced Young's Modulus. When …
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Topology Optimization of Multifunctional Nanocomposite Structures
… stiffness, electrical conductivity, and piezoresistivity. These local properties in turn drive global multifunctional performance objectives. A topology optimization algorithm determines the optimal distribution of CNTs within an epoxy matrix in an effort to design a set of structures …
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Coupled Electromechanical Peridynamics Modeling of Strain and Damage Sensing in Carbon Nanotube Reinforced Polymer Nanocomposites
… of CNT nanocomposites at multiple length scales. Piezoresistivity is the coupling between the electrical properties of a material and applied mechanical loads, more specifically the change in resistance in response to deformation. This can include both, a geometric effect due to change in …
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Flexible and foldable single-crystalline silicon electronics for various applications
… Next, we modeled strain sensors based on piezoresistivity that offer high sensitivity, lightweight construction, and mechanical flexibility so that they can be used in various applications, including structural health monitoring, tactile image detection, cardiovascular pressure …
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Graphite-enabled Cementitious Composites: A Smart and Resilient Solution for Future Infrastructure
… chemical, mechanical, electro-conductivity and piezoresistivity properties of the graphite-cement composites. Results showed an effective mixing with a uniform dispersion of the graphite with good hydration, adequate workability and enhanced strength of the composites with graphite …
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CHARACTERIZATION OF SENSING REPAIR MATERIALS
… MPa were modified to have sensing capabilities. Piezoresistivity was considered as the sensing property and materials were tested under various service conditions in terms of strength and sensitivity. In addition, real-time application of such smart materials for low stress disaster monitoring …
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Piezoresistive Sensing of Bistable Micro Mechansim State
… modeling techniques of MEMS devices which use piezoresistivity for position sensing. A fully compliant bistable micro mechanism was designed, fabricated, and tested to demonstrate the feasibility of this sensing technique. Testing results from two fabrication processes, Fairchild's SUMMiT IV …
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Integration of electronic and optical techniques in the design and fabrication of pressure sensors
… parts of the sensor. Physical principles of piezoresistivity and Fabry-Perot interferometry were applied in designing an integrated sensor and in determining analytic models for the respective electronic and optical outputs. Several test pressure sensors were produced and their performance …
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Numerical Modeling Analysis of Wafer Warpage and Carrier Mobility Change due to Tapered Through-Silicon-Via Geometry
… the carrier mobility in transistors. This piezoresistivity effect can cause serious reliability concerns. The size of keep-out zone (KOZ), which is identified as a threshold of 5% carrier mobility change, was also quantified for various transistor types in different channel directions.
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Piezoresistive Hybrid Nanocomposites for Strain and Damage Sensing: Experimental and Numerical Analysis
… of electrical percolation, conductivity, and piezoresistivity in hybrid nanocomposites, the author develops a two-dimensional (2D) and a three-dimensional (3D) computational Monte Carlo percolation network models for hybrid nanocomposites with CNT and GNP fillers.</p> <p>In the experimental …
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Towards structural health monitoring in carbon nanotube reinforced composites
… CNT network architecture beyond the inherent piezoresistivity of the CNT heavily influences the NDE capabilities of using CNTs as strain or damage sensors. Results also suggest that CNT network architecture must be further optimized to achieve reliable NDE and SHM, and may depend on the …
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Development and Characterization of Piezoresistive Nanocomposites for Sensing Applications
… improvement in both electrical conductivity and piezoresistivity is observed with the combination of CNTs and GNPs, indicating the formation of efficient hybrid conductive networks for strain and electrical transfer in the material. Different matrix materials have been compared to investigate the …
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Hypervelocity Impact Analysis of Hybrid Nanocomposite Sensors for Inflatable Space Structures
… to their excellent electrical properties and piezoresistivity. A new method was developed to cut graphite sheet (composed of GNPs) in laser marker and distribute it in patterns on carbon nanotube sheet (buckypaper) in epoxy matrix. Piezoresitivity tests were carried out and results were …
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Microfabrication of conductive polymer nanocomposite for sensor applications
… of mechanical flexibility and electrical piezoresistivity. To demonstrate feasibility for practical sensor applications, two sensor prototypes were constructed. The strain sensor, for example, showed significant resistive response while sample withheld large range tensile strain of over …
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Design of Piezoresistive MEMS Force and Displacement Sensors
… of choice in many MEMS fabrication processes. Piezoresistivity—the change of electrical resistance due to an applied strain—is a valuable material property of silicon due to its potential for high signal output and on-chip and feedback-control possibilities. However, successful design of …
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