Global ETD Search
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 18 of 18 for “"electromechanical response"”.
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Electromechanical response of textured ferroelectric PZT thin film stacks
… (PZT) offer several advantages to microelectromechanical systems (MEMS) due to their low power requirements, large displacements, high work and power densities, as well as high sensitivity in a wide dynamic range. The performance of PZT-based MEMS can be further improved by increasing …
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Soft nanocomposites with enhanced electromechanical response for dielectric elastomer actuators
Electromechanical transducers based on elastomer capacitors are presently considered for many soft actuation applications, due to their large reversible deformation in response to electric field induced electrostatic pressure. The high operating voltage of such devices is currently a large …
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Effects of stress on material properties, intrinsic and extrinsic behavior, and electromechanical response of stress-biased actuators
… into the fundamental effects of stress on the electromechanical behavior of these devices...This investigation resulted in a greater understanding of the general behavior of ferroelectric materials under the unique mechanical boundary conditions associated with these devices, and the balance …
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High-strain actuation of lead-free perovskites : compositional effects, phenomenology and mechanism
… out to map the compositional dependence of electromechanical behavior and ferroelectric phase stability in the barium, zirconium-codoped sodium bismuth titanate (BNBZT) system for barium concentrations up to 18 mol.% and zirconium concentrations up to 4 mol.%. A number of polycrystalline …
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Electrically induced antiferroelectric-ferroelectric phase transformations in lead-zirconate titanate stannate ceramics
… microstructure-property relations, and (iii) electromechanical response of the field-induced transformation behavior for actuator applications. A thermodynamic model is proposed to account for the thermal stability of the field-induced transformation characteristics, including reversible and …
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Power Systems Analysis in the Power-Angle Domain
… are included in the model, which allows the electromechanical response to be solved using conventional circuit analysis techniques. The effect of generation trips, load switching, and line switching can be quickly approximated with nodal analysis or mesh analysis in the power-angle domain. …
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Molecular-scale devices from first principles
… oligothiophenes is the driving force behind an electromechanical response. The oligothiophenes are attracted to each other through p-stacking interactions driven by redox reactions. We show that counterions strengthen this interaction further through enhanced screening of the electrostatic …
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Additively Manufactured Dielectric Elastomer Actuators: Development and Performance Enhancement
… energy density polymers with fast and reversible electromechanical response. Additionally, the electrically driven work principle allows DEs to be distributed in a desired fashion and function locally with minimum interference. Thus, a great effort is being made towards utilizing additive …
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Development and Characterization of Piezoresistive Nanocomposites for Sensing Applications
… that yields increased strains, flexibility, and electromechanical response. The electromechanical behavior of the hybrid composites is investigated both under static and dynamic loading at various frequencies with induced levels of strains, and has shown positive response under all tested …
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Structure-property correlations in compositionally complex ferroelectrics
… Relaxor ferroelectrics show exceptional electromechanical response, energy storage capacity, and electrocaloric properties, finding applications ranging from ultrasound imaging to electrical energy storage systems. These materials show nanoscale chemical and structural heterogeneity that …
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Nanometer-thick oxide films for pyroelectric energy conversion
… techniques measured high-temperature electromechanical and pyroelectric response in ~100 nm thick PbZr0.2Ti0.8O3 films deposited using pulsed laser deposition. Piezoresponse force microscopy (PFM), an atomic force microscopy (AFM) based technique, measured the electromechanical …
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DESIGN, MANUFACTURING, AND CHARACTERIZATION OF SOFT, CAPACITIVE ACTUATORS AND ARCHITECTED DIELECTRIC ELASTOMERS
… geome- try and scale for tuning the matrices’ electromechanical response. We observed effective permittivity shifts ∆ε2 > 0.7 under compressive strains γ < 0.35. With the ability to tune their effective mechanical behavior, the architected elastomers are more flexible than their bulk …
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Leveraging Carbon Based Nanoparticle Dispersions for Fracture Toughness Enhancement and Electro-mechanical Sensing in Multifunctional Composites
… are first evaluated to study the binder's electromechanical response, followed by AP/MWCNT/PDMS (inert nPBE) to assess the impact of AP addition, and finally, AP/AL/MWCNT/PDMS (active nPBE-AL) to evaluate the impact of adding conductive aluminum grains. Compression samples (ASTM D695) were …
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Electrostatic micro actuators for mirror and other applications
… equation is developed to represent the coupled electromechanical response of the system under applied voltage bias, and a pull in equation is determined to identify the intrinsic collapse point beyond which an actuator system no longer has a stable equilibrium, the so-called pull in point. These …
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Aerodynamic and Electromechanical Design, Modeling and Implementation Of Piezocomposite Airfoils
… and experimental analysis of the aerodynamic and electromechanical systems that are necessary for a practical implementation of a piezocomposite airfoil is presented. First, the electromechanical response of Macro-Fiber Composite based unimorph and bimorph structures is analyzed. A distributed …
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Electromechanical Characterization of the Static and Dynamic Response of Dielectric Elastomer Membranes
… in order to characterize its static and dynamic electromechanical behavior. In both cases, the experiments were conducted with prestretched dielectric elastomer actuators fabricated from 0.5 mm or 1 mm thick polyacrylate films and unless stated otherwise carbon grease electrodes were used. The …
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Surface Acoustic Waves Propagation and Coupling Fields in Piezomagnetic and Piezoelectric Semiconductor Layered Structures
… in composite structures are explained, and the electromechanical (ME) coupling responses with multi-physical fields are analyzed, which is of guiding significance for the design of magnetically related SAW devices and piezotronic devices. The main studies include: (1) Based on the …
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Synthesis-Structure-Property Relationships in Lead-Free Piezoelectric Materials
… piezoelectrics used for actuators. The electromechanical properties required for actuators (high piezoelectric constant, high coupling factor, low loss, and high transition temperatures) for known lead-free compositions are, however, far inferior to those of lead-based systems. There are …