Current Search:  Piezoelectricity (x)

View All Items

  • CSV Spreadsheet
(1 - 6 of 6)
Concurrent engineering design of a miniature piezo-transducer-vibrator
Title
Concurrent engineering design of a miniature piezo-transducer-vibrator.
Creator
Hedayatnia, Mostafa., Florida Atlantic University, Mazouz, Abdel Kader, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
A state-of-the-art Piezo-Transducer-Vibrator suitable for a wristwatch has been developed based on a "Customer Comprehension" program: To look at the product from the customer point of view and try to satisfy those needs simultaneously using computer simulation leading to a reliable design in a shorter cycle time. This device is a miniature integrated compact form of both audio and silent alerts which uses less than 8 mA current; desirable to be used in equipments with very small power...
Show moreA state-of-the-art Piezo-Transducer-Vibrator suitable for a wristwatch has been developed based on a "Customer Comprehension" program: To look at the product from the customer point of view and try to satisfy those needs simultaneously using computer simulation leading to a reliable design in a shorter cycle time. This device is a miniature integrated compact form of both audio and silent alerts which uses less than 8 mA current; desirable to be used in equipments with very small power sources. A new ergonomic study was conducted in comprehending the minimum acceptable shake and frequency on human wrist. The complete Piezo-bender structure, its driving format, and its vibration has been modeled accurately to obtain an optimum geometry design for the best possible shake, satisfying all constraints.
Show less
Date Issued
1994
PURL
http://purl.flvc.org/fcla/dt/12358
Subject Headings
Piezoelectric transducers, Wrist watches, Vibrators
Format
Document (PDF)
Modeling piezoelectric material and ultrasound transducers
Title
Modeling piezoelectric material and ultrasound transducers.
Creator
Crimi, Sarah., Harriet L. Wilkes Honors College
Abstract/Description
We discuss piezoelectric and piezoceramic material as well as ultrasound transducers. We study the analytical methods for calculating the impedance of a simple bar of piezoceramic material and a simple ultrasound transducer, and discuss the methodology behind the numerical technique (Finite Element Method) to model a complex ultrasound transducer. With a simple ultrasound transducer model created in the software program PZex, we find out how the impedance is aected when the scale of the...
Show moreWe discuss piezoelectric and piezoceramic material as well as ultrasound transducers. We study the analytical methods for calculating the impedance of a simple bar of piezoceramic material and a simple ultrasound transducer, and discuss the methodology behind the numerical technique (Finite Element Method) to model a complex ultrasound transducer. With a simple ultrasound transducer model created in the software program PZex, we find out how the impedance is aected when the scale of the relative permittivity is varied. We then create a working model of a complex ultrasound transducer and learn how impedance is affected by varying the size of the electrode driven and adding a propagation layer. We saw that there was not a direct relationship between varying the relative permittivity and the change in impedance as we expected. We saw that varying the size of the electrode and adding a propagation layer created expected impedances.
Show less
Date Issued
2010
PURL
http://purl.flvc.org/FAU/3334250
Subject Headings
Piezoelectric transducers, Finite element method, Ultrasonic waves, Microelectromechanical systems
Format
Document (PDF)
Acceleration charge sensitivity in AT-quartz resonators
Title
Acceleration charge sensitivity in AT-quartz resonators.
Creator
Anderson, Clifford L. H., Florida Atlantic University, Bagby, Jonathan S.
Abstract/Description
The behavior of AT-quartz resonators subject to acceleration is studied. For an AT strip resonator with cantilever mounting, piezoelectric theory predicts that excitation of the pure lowest frequency flexural mode of vibration generates no charge. However, experiments show electromechanical resonance corresponding to this mode for sinusoidal support motion normal to the plane of the crystal with no applied electric field. An amplifier with a voltage follower first stage senses charge output...
Show moreThe behavior of AT-quartz resonators subject to acceleration is studied. For an AT strip resonator with cantilever mounting, piezoelectric theory predicts that excitation of the pure lowest frequency flexural mode of vibration generates no charge. However, experiments show electromechanical resonance corresponding to this mode for sinusoidal support motion normal to the plane of the crystal with no applied electric field. An amplifier with a voltage follower first stage senses charge output from the crystal. Shielding is required to reduce sixty hertz and drive frequency electromagnetic interference. Measurement of resonant frequency and damping factor for the lowest frequency flexural mode is reported for a group of 17.76 MHz oscillator crystals. This mode is responsible for crystal breakage in some portable communications products. Significant variation in sensitivity among crystals was observed. Charge sensitivity of this mode is attributed in part to mechanical coupling to other modes involving torsion and lateral flexure.
Show less
Date Issued
1995
PURL
http://purl.flvc.org/fcla/dt/15126
Subject Headings
Quartz crystals, Piezoelectricity, Oscillators, Crystal, Resonators, Acceleration (Mechanics)
Format
Document (PDF)
Finite element modeling of composite laminates with embedded piezoelectric structures including debonding
Title
Finite element modeling of composite laminates with embedded piezoelectric structures including debonding.
Creator
Suarez, Beatriz., Florida Atlantic University, Tsai, Chi-Tay, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
Piezoelectric sensors are one of the primary devices used in smart structures because of their capability to act as both, sensors and actuators. A finite element model has been developed to predict elastic behavior and electrical response of laminate composites with embedded piezoelectric sensors. Correlations with experimental results indicate that the model is capable of forecasting the elastic and electrical response of the structure with good accuracy. The important issue of debonding of...
Show morePiezoelectric sensors are one of the primary devices used in smart structures because of their capability to act as both, sensors and actuators. A finite element model has been developed to predict elastic behavior and electrical response of laminate composites with embedded piezoelectric sensors. Correlations with experimental results indicate that the model is capable of forecasting the elastic and electrical response of the structure with good accuracy. The important issue of debonding of any of the faces of the sensors is also studied in the current work. Finite element results indicate significant changes in the elastic response caused by debonding, as well as unreliable electrical outputs.
Show less
Date Issued
1998
PURL
http://purl.flvc.org/fcla/dt/15603
Subject Headings
Finite element method, Piezoelectric materials, Laminated materials, Smart structures
Format
Document (PDF)
Impact analysis of a piezo-transducer-vibrator
Title
Impact analysis of a piezo-transducer-vibrator.
Creator
Karabiyik, Necati., Florida Atlantic University, Tsai, Chi-Tay, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
Piezo-Transducer-Vibrators are miniature devices that emit both audio and silent signals and are currently targeted for use as an integral part of wristwatch technology. Utilizing nonlinear finite element analysis is essential for obtaining a greater understanding of the system response under varying conditions. Dyna3D nonlinear finite element code is applied in this analysis with the focus on the mechanical aspects of the vibrator. Four impact variables, the velocity, the plate gap, the...
Show morePiezo-Transducer-Vibrators are miniature devices that emit both audio and silent signals and are currently targeted for use as an integral part of wristwatch technology. Utilizing nonlinear finite element analysis is essential for obtaining a greater understanding of the system response under varying conditions. Dyna3D nonlinear finite element code is applied in this analysis with the focus on the mechanical aspects of the vibrator. Four impact variables, the velocity, the plate gap, the weight and the velocity angle are studied to determine the effects on the system response. Each impact variable is assigned three separate values, creating twelve programs for analysis. For each program, responses to impact conditions are studied demonstrating the deformed mode shapes, maximum principal stresses and maximum displacements using state database plots and time-history plots.
Show less
Date Issued
1994
PURL
http://purl.flvc.org/fcla/dt/15008
Subject Headings
Piezoelectric transducers, Finite element method, Wrist watches, Vibrators
Format
Document (PDF)
SUPPORTED ERYTHROCYTE MEMBRANES ON PIEZOELECTRIC SENSORS FOR STUDYING THE INTERACTIONS BETWEEN NANOPARTICLES AND SURFACES OF RED BLOOD CELLS
Title
SUPPORTED ERYTHROCYTE MEMBRANES ON PIEZOELECTRIC SENSORS FOR STUDYING THE INTERACTIONS BETWEEN NANOPARTICLES AND SURFACES OF RED BLOOD CELLS.
Creator
Islam, Tanaz, Yi, Peng, Florida Atlantic University, Department of Civil, Environmental and Geomatics Engineering, College of Engineering and Computer Science
Abstract/Description
The Supported red blood cell membrane (SRBCm) was developed on a piezoelectric sensor to study the attachment of nanoparticles to erythrocyte surfaces. A well-dispersed colloidal suspension of fragments of RBCm was prepared from whole blood, and characterized thoroughly using cryogenic transmission electron microscopy, dynamic light scattering, and zeta potential analysis. To develop SRBCm, RBCm fragments were immobilized onthe sensor in a quartz crystal microbalance with dissipation...
Show moreThe Supported red blood cell membrane (SRBCm) was developed on a piezoelectric sensor to study the attachment of nanoparticles to erythrocyte surfaces. A well-dispersed colloidal suspension of fragments of RBCm was prepared from whole blood, and characterized thoroughly using cryogenic transmission electron microscopy, dynamic light scattering, and zeta potential analysis. To develop SRBCm, RBCm fragments were immobilized onthe sensor in a quartz crystal microbalance with dissipation monitoring system. A complete monolayer of flattened fragments of RBCm was formed on the positively charged surface of the piezoelectric sensor in 1 mM NaCl and 0.2 mM NaHCO3 at pH 7.1. The surface morphology of SRBCm was characterized via atomic force microscopy. The even distribution of surface proteins expressed on erythrocytes was found on SRBCm through indirect immunofluorescence microscopy. The attachment efficiencies of model nanoparticles, e.g. hematite nanoparticles and carboxylated polystyrene nanoparticles, on the SRBCm were quantified using a classic methodology. KEYWORDS: Supported erythrocyte membrane, piezoelectric sensor, phospholipid bilayers, nanoparticles
Show less
Date Issued
2019
PURL
http://purl.flvc.org/fau/fd/FA00013383
Subject Headings
Erythrocyte Membrane, Piezoelectric polymer biosensors, Nanoparticles, Phospholipid bilayers, Bilayer lipid membranes
Format
Document (PDF)