Piezoelectric and Capacitative Microactuators and Devices

1993 ◽  
Vol 310 ◽  
Author(s):  
M. Sayer ◽  
D. Barrow ◽  
L. Zou ◽  
C.V.R. Vasant Kumar ◽  
R. Noteboom ◽  
...  
Keyword(s):  
Silicon Nitride ◽  
Polymer Films ◽  
High Frequency ◽  
Sol Gel ◽  
Polymer Membranes ◽  
Ultrasonic Transducers ◽  
Resonant Excitation ◽  
Piezoelectric Sensors ◽  
Pzt Films

AbstractUltrasonic transducers, microactuators and resonators using sol gel PZT films, polymer membranes and silicon machining techniques can take the form of cantilevers, membranes, and array sensors. Static deflections in simple electrode configurations for PZT films supported on silicon or silicon nitride membranes are of the order of 1 μm, while larger deflections can be developed under ac and resonant excitation. High frequency acoustic actuators using capacitative excitation of polymer films have been used to evaluate the performance of piezoelectric sensors.

Integration of PZT on SOI Wafers: Increasing Piezoelectric Film Thickness for Providing a Wide Range of Ultrasonic MEMS Applications

2006 ◽  
Vol 969 ◽  
Author(s):  
Brahim Belgacem ◽  
Florian Calame ◽  
Paul Muralt
Keyword(s):  
Electromechanical Coupling ◽  
Piezoelectric Coefficient ◽  
Sol Gel ◽  
Equivalent Circuit Model ◽  
Ultrasonic Transducers ◽  
Electromechanical Coupling Coefficient ◽  
Wide Range ◽  
Pzt Films ◽  
Gel Technique ◽  
Quality Factor Q

AbstractPiezoelectric micromachined ultrasonic transducers comprising a 10 μm thick Si device layer and a 1-4 μm thick piezoelectric PZT layer were investigated. The PZT films were deposited by a sol-gel technique. The transverse piezoelectric coefficient was measured as -14.9 C/m2. The electromechanical coupling increased with PZT thickness, as expected. The influence of both the shape and area of the top electrode on the device performance has been investigated. The electromechanical coupling coefficient (k) and quality factor (Q) have been measured in air and were fitted to an equivalent circuit model. The maximal k2 was obtained as 7.8%.

Piezoelectric Micromachined Ultrasonic Transducers Based on PZT Films

2002 ◽  
Vol 741 ◽  
Author(s):  
Jacek Baborowski ◽  
Nicolas Ledermann ◽  
Paul Muralt
Keyword(s):  
Thin Film ◽  
Sol Gel ◽  
Basic Element ◽  
Ultrasonic Transducers ◽  
Silicon Membrane ◽  
Good Definition ◽  
Pzt Thin Film ◽  
Pzt Films ◽  
Definition Of ◽  
Insulating Liquid

ABSTRACTTest structures for piezoelectric micromachined ultrasonic transducers have been fabricated and investigated. The basic element consisted of a oxidized and platinized silicon membrane coated with a 2 μm thick (100)-textured Pb(Zr,Ti)O3 (PZT) thin film deposited by sol-gel techniques. SOI wafers have been applied to obtain a good definition of the silicon part of the membrane. Test devices have been characterized in air and in an insulating liquid.

Electron microscopy studies of PZT ferroelectric film capacitor structures

1992 ◽  
Vol 50 (2) ◽  
pp. 1364-1365
Author(s):  
V. Kaushik ◽  
P. Maniar ◽  
J. Olowolafe ◽  
R. Jones ◽  
A. Campbell ◽  
...  
Keyword(s):  
Electric Fields ◽  
Sol Gel ◽  
Ferroelectric Material ◽  
Dielectric Constants ◽  
Dielectric Films ◽  
Lead Zirconium Titanate ◽  
Si Substrate ◽  
Film Capacitor ◽  
Pzt Films ◽  
High Dielectric

Lead zirconium titanate films (Pb (Zr,Ti) O3 or PZT) are being considered for potential application as dielectric films in memory technology due to their high dielectric constants. PZT is a ferroelectric material which shows spontaneous polarizability, reversible under applied electric fields. We report herein some results of TEM studies on thin film capacitor structures containing PZT films with platinum-titanium electrodes.The wafers had a stacked structure consisting of PZT/Pt/Ti/SiO2/Si substrate as shown in Figure 1. Platinum acts as electrode material and titanium is used to overcome the problem of platinum adhesion to the oxide layer. The PZT (0/20/80) films were deposited using a sol-gel method and the structure was annealed at 650°C and 800°C for 30 min in an oxygen ambient. XTEM imaging was done at 200KV with the electron beam parallel to <110> zone axis of silicon.Figure 2 shows the PZT and Pt layers only, since the structure had a tendency to peel off at the Ti-Pt interface during TEM sample preparation.

High frequency ultrasonic estimation of C-crack defects in silicon nitride bearing balls

2007 ◽  
Author(s):  
François Deneuville ◽  
Mohammed Ourak ◽  
Marc Duquennoy ◽  
Mohammadi Ouaftouh ◽  
Frédéric Jenot ◽  
...  
Keyword(s):  
Silicon Nitride ◽  
High Frequency

Sol-Gel Derived PZT Thick Films with Nano-Sized Microstructure

2002 ◽  
Vol 748 ◽  
Author(s):  
C. L. Zhao ◽  
Z. H. Wang ◽  
W. Zhu ◽  
O. K. Tan ◽  
H. H. Hng
Keyword(s):  
Lead Zirconate Titanate ◽  
Electromechanical Coupling ◽  
Thick Films ◽  
Sol Gel ◽  
Essential Element ◽  
Processing Parameters ◽  
Lead Zirconate ◽  
Piezoelectric Response ◽  
Coupling Coefficients ◽  
Pzt Films

ABSTRACTLead zirconate titanate (PZT) films are promising for acoustic micro-devices applications because of their extremely high electromechanical coupling coefficients and excellent piezoelectric response. Thicker PZT films are crucial for these acoustic applications. A hybrid sol-gel technology has been developed as a new approach to realize simple and cost-effective fabrication of high quality PZT thick films. In this paper, PZT53/47 thick films with a thickness of 5–50 μm are successfully deposited on Pt-coated silicon wafer by using the hybrid sol-gel technology. The obtained PZT thick films are dense, crack-free, and have a nano-sized microstructure. The processing parameters of this technology have been evaluated. The microstructure of the film has been observed using field-emission scanning electron microscopy and the crystallization process has been monitored by the X-ray diffraction. The thick films thus made are good candidates for fabrication of piezoelectric diaphragm which will be an essential element of microspeaker and microphone arrays.

Fabrication of thick Pb(Zr,Ti)O3 (PZT) films by modified sol–gel methods for application in MEMS

2002 ◽  
Vol 2 (3) ◽  
pp. 159-171 ◽  
Author(s):  
Jian Lu ◽  
Yan Yang ◽  
Wenhao Huang ◽  
Jiaru Chu
Keyword(s):  
Sol Gel ◽  
Pzt Films

Continuous fabrication platform for highly aligned polymer films

TECHNOLOGY ◽  
2014 ◽  
Vol 02 (03) ◽  
pp. 189-199 ◽  
Author(s):  
James Loomis ◽  
Hadi Ghasemi ◽  
Xiaopeng Huang ◽  
Nagarajan Thoppey ◽  
Jianjian Wang ◽  
...  
Keyword(s):  
Polymer Films ◽  
Sol Gel ◽  
Batch Processes ◽  
Mechanical And Thermal Properties ◽  
High Shear ◽  
Drawing Process ◽  
Polymer Gel ◽  
Drawing System ◽  
Bulk Polymers ◽  
Continuous Fabrication

Superior mechanical and thermal properties in bulk polymers can be achieved by aligning the molecular chains through drawing-induced plastic deformation. Although highly aligned polymer films (HAPFs) are in demand, current fabrication methods are limited to manual, lab-scale batch processes. Here we report a continuous fabrication platform for HAPFs consisting of a three-step sol-gel extrusion, structure freezing and drying, and mechanical drawing process. First, a polymer-solvent solution is subjected to a high shear, high temperature, Couette flow extrusion into a thin film, resulting in initial chain disentanglement. Next, the extruded disentangled structure is frozen using a liquid N 2-cooled substrate, and then solvent is removed from polymer gel through ambient evaporation. Finally, dried films are mechanically drawn within a heated enclosure using a constant-force adaptive-thickness drawing system. The performance of this platform has been confirmed by fabricating polyethylene HAPFs with > 99% crystallinity and draw ratios up to 100× (creating continuous films > 15 m in length).

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