Electromechanical Behavior in Micromachined Piezoelectric Membranes

2003 ◽  
Vol 782 ◽  
Author(s):  
M. C. Robinson ◽  
J. C. Raupp ◽  
I. Demir ◽  
C. D. Richards ◽  
R. F. Richards ◽  
...  

ABSTRACTPiezoelectric materials can convert mechanical and electrical energy, a particularly useful tool in developing micro and nanoscale systems. Characterizing the electromechanical behavior is essential to the design and optimization of the material's and device's performance. This paper examines the influence of boundary (clamping) conditions, relative thickness variations between the active one to two micron thick piezoelectric membrane and underlying passive support structure, and the electrode coverage on the electromechanical behavior. Membranes were fabricated with silicon and lead zirconate titanate (PZT) with a ratio of Zr to Ti of 40:60 that provide thickness ratios between 1:2 and 2:1 by depositing the PZT using sequential solution deposition. PZT films contain a tensile stress that accumulates during processing, therefore a compressive stressed layer of tungsten was sputtered on bulk micromachined membranes to produce a near zero net residual stress. A nonlinear finite element numerical simulation technique is utilized for the analysis of the composite thin film. A comparison between the behavioral trends determined by simulation and experimental methods will be discussed.

2005 ◽  
Vol 872 ◽  
Author(s):  
M.C. Robinson ◽  
P.D. Hayenga ◽  
J.H. Cho ◽  
C.D. Richards ◽  
R.F. Richards ◽  
...  

AbstractPiezoelectric materials convert mechanical to electrical energy under stretching and bending conditions. Optimizing the coupling conversion is imperative to the electromechanical behavior of a micromachined membrane's performance. This paper discusses analytical calculations that were devised to determine the microscale structure that minimizes residual stress and outlines the implementation of fabrication technique variations including three different electrode configurations, trenching around the membrane, and reducing the total composite residual stress of the support structure using compressive silicon oxide. Lead zirconacte titanate (PZT) films between 1 and 3 μm thick with a ratio of Zr to Ti of 40:60 were deposited onto 3 mm square silicon membranes. The total tensile stress in the composite structure reaches 100 MPa during standard fabrication processing. Utilizing analytical calculations, a structure was determined that lowered the residual stress of the composite to 11 MPa and increased the electromechanical coupling 35 times. Changing the geometry of the electrode coverage decreased the residual stress of the composite by 40%. Trenching around the membrane provided a membrane with boundary conditions that approached simply supported and decreased the composite residual stress by another 16%. A comparison of the electromechanical behavior for these structures will be discussed, showing a route towards increasing electromechanical coupling in PZT MEMS.


2018 ◽  
Vol 197 ◽  
pp. 11011
Author(s):  
Eka Defiyani ◽  
Porman Pangaribuan ◽  
Denny Darlis

Indonesia is a country that has a fairly high rainfall, because it is located in the tropical area. This condition could be a potential for generating electrical energy from raindrops. If the heavy raindrop collide the piezoelectric materials, it can generate electrical energy. The piezoelectric effect was discovered by Jacques and Pierre Curie in 1880. They found that certain materials, when subjected to mechanical strain, suffered an electrical polarization that was proportional to the applied strain. This piezoelectric effect converts mechanical strain into electrical voltage. The molecular structure of piezoelectric materials produces a coupling between electrical and mechanical domains. In this research, raindrops will be exploited to produce electric voltage by piezoelectric transducer. Piezoelectric transducer used in this research is Lead Zirconate Titanate type. Energy conversion processing occurred when raindrop collide the polymer layer of piezoelectric and make an unelastic thrust on its surface. The designed system consists of raindrops collector board and serial connected piezoelectric transducer. From system above, highest voltage, reach is 3.13 VAC for 30 piezoelectric and the average voltage is 2.617 V. This results show us the potential usage of raindrops energy generator using piezoelectric transducer for tropical countries.


2012 ◽  
Vol 535-537 ◽  
pp. 1507-1511 ◽  
Author(s):  
De Yi Zheng ◽  
Jonathan Swingler ◽  
Paul M. Weaver

Piezoelectric materials because their special ability to convert bwteen kinetic energy and electrical energy. Therefore, they are widely applicated in the areas such as sensors, resonators etc. However, the electrical degradation phenomenon of piezoelectric materials will cause the degradation of their performance. The electrode materails has been reported can severely influence the electrical degradation of piezoelectric materials. In this paper, the life time of the lead zirconate titanate capacitors with nickel, gold or silver electrodes are investigated. It is suggested that, the poor migration ability of the electrode elements gives the PZT capacitors a longer lifetime. The reason of no observation of the electrode materials in the capacitor material is also discussed.


2001 ◽  
Vol 666 ◽  
Author(s):  
B.W. Olson ◽  
L.M. Randall ◽  
C.D. Richards ◽  
R.F. Richards ◽  
D.F. Bahr

ABSTRACTPiezoelectric oxide films, such as lead zirconate titanate (PZT), are now being integrated into MEMS applications. Many PZT derived systems are deposited using a sol-gel process, which can be used in a microelectronics processing route using spin coating as the deposition method. An application of interest for PZT films is in power generation, where a flexing membrane is used to transform mechanical to electrical energy. The current study was undertaken to identify the relationships between the processing, microstructure, and mechanical reliability of these films. Films were deposited onto both monolithic and bulk micromachined platinized silicon wafers using standard sol-gel chemistries, with roughness and grain size tracked using electron and scanning probe microscopy. Mechanical properties were evaluated in a dynamic bulge testing apparatus. Grain size variations in the Pt film between 35 and 125 nm are shown to have little effect on grain size of the subsequent PZT film and the adhesion of the PZT to the Pt film. Only the Pt film with 125 nm grains was shown to undergo any significant interfacial fracture. Fatigue tests suggest film lifetime is primarily limited by the number of pre- existing flaws in the film from processing. Reducing the microcrack density has been shown to produce films and devices that fail at strains of 1.4% and have mechanical fatigue lifetimes in excess of 100 million cycles at strains simulating the operating conditions.


2021 ◽  
Vol 9 (1) ◽  
pp. 1321-1328
Author(s):  
Abdul Aziz Khan J , Shanmugaraja P , Kannan S

MEMS Energy Harvesting(EH) devices are excepted to grow in the upcoming years, due to the increasing aspects of MEMS EH devices in vast applications. In Recent advancements in energy harvesting (EH) technologies wireless sensor devices play a vital role to extend their lifetime readily available in natural resources. In this paper the design of MEMS Cantilever at low frequency (100Hz) with different piezoelectric materials Gallium Arsenide (GaAs), Lead Zirconate Titanate (PZT-8), Tellurium Dioxide (TeO2), Zinc oxide (ZnO) is simulated and performance with different materials are compared. The results are analyzed with various parameters such as electric potential voltage, von mises stress, displacement. The paper discusses the suitability of the piezoelectric material for MEMS fully cochlear implantable sensor application.


2013 ◽  
Vol 8 (1) ◽  
pp. 155892501300800
Author(s):  
François M. Guillot ◽  
Haskell W. Beckham ◽  
Johannes Leisen

In the past few years, the growing need for alternative power sources has generated considerable interest in the field of energy harvesting. A particularly exciting possibility within that field is the development of fabrics capable of harnessing mechanical energy and delivering electrical power to sensors and wearable devices. This study presents an evaluation of the electromechanical performance of hollow lead zirconate titanate (PZT) fibers as the basis for the construction of such fabrics. The fibers feature individual polymer claddings surrounding electrodes directly deposited onto both inside and outside ceramic surfaces. This configuration optimizes the amount of electrical energy available by placing the electrodes in direct contact with the surface of the material and by maximizing the active piezoelectric volume. Hollow fibers were electroded, encapsulated in a polymer cladding, poled and characterized in terms of their electromechanical properties. They were then glued to a vibrating cantilever beam equipped with a strain gauge, and their energy harvesting performance was measured. It was found that the fibers generated twice as much energy density as commercial state-of-the-art flexible composite sensors. Finally, the influence of the polymer cladding on the strain transmission to the fiber was evaluated. These fibers have the potential to be woven into fabrics that could harvest mechanical energy from the environment and could eventually be integrated into clothing.


Author(s):  
Ryan Rudy ◽  
Adam J. Cohen ◽  
Jeffrey S. Pulskamp ◽  
Ronald G. Polcawich ◽  
Kenn R. Oldham

Terrestrial and other millimeter-scale autonomous micro-robots face significant challenges in surveying their environment, due to small power budgets and payload capacities. One low-power, low-mass form of obstacle detection is tactile sensing of contact with other surfaces. In this-paper, a tactile sensor inspired by insect antennae is described, based on thin-film lead-zirconate-titanate (PZT) transduction. Thin-film piezoelectric materials permit actuation and sensing mechanisms to be coupled in very small, compact structures, as well as complement previously developed microrobotic leg mechanisms. Key design parameters for the tactile sensor are introduced and analyzed in terms of sweep frequency and range of motion, and signals from sensor impact are predicted. Experimental results with partially-released prototype actuators show respectable agreement with modeled behavior for dynamic motion, though impact detection is hampered by large feedthrough disturbances. Completed sensors range from 2 to 4 mm in length and are approximately 500 μm in width, with a sweep range of nearly 1 mm demonstrated from a 2 mm long prototype.


2020 ◽  
Vol 31 (13) ◽  
pp. 1594-1603
Author(s):  
Tejkaran Narolia ◽  
Vijay K Gupta ◽  
IA Parinov

A rotary-type energy harvester for the applications having space restrictions has been designed and developed to harvest the energy from rotary motion system. The rotation kinetic energy is converted into electrical energy through a lead zirconate titanate patch, which is strained by magnetic force. Most of the researchers used d31 mode of the piezoelectric material of such conversion. Some researchers have explored d33 mode harvester with piezo patch along the circumferential direction. In this article, d33 mode of harvesting with radial direction piezo patch has been proposed. Mathematical and finite element models are developed to calculate the harvested energy. The results are experimentally verified. The average output power of 14.48 nW is generated corresponding to the magnetic force of 0.3126 N and rotational speed of 2100 r/min. The results from the mathematical and finite element models are observed to be consistent with the experimental results. Such harvester will be useful for the applications having space limitations such as self-power generation in an artillery shell and rotary projectile.


2002 ◽  
Vol 741 ◽  
Author(s):  
M.S. Kennedy ◽  
D.F. Bahr ◽  
C.D. Richards ◽  
R.F. Richards

ABSTRACTFlexing piezoelectric membranes can be used to convert mechanical energy to electrical energy. The overall deflection of individual membranes is impacted by the residual stress in the system. Membranes comprised of silicon dioxide, Ti/Pt, lead- zirconate- titanate (PZT), and TiW/Au layers deposited on a micromachined boron doped silicon wafer were examined for both morphology and residual stress. By characterizing the membrane residual stress induced during processing with x-ray diffraction, wafer curvature, and bulge testing and identifying methods to reduce stress, the membrane performance and reliability can be optimized. For Zr:Ti ratios of 52:48, the residual stress in the PZT was 350 MPa tensile, with an overall effective stress in the composite membrane of 150 MPa. A reduction of stress was accomplished by changing the PZT chemistry to 40:60 Zr:Ti in the PZT to obtain a stress in the PZT of 160 MPa tensile and an overall effective membrane stress of 100 MPa. The crystallization of the 52:48 PZT film at 700 °C causes a 28% reduction in the thickness of the film.


2006 ◽  
Vol 21 (3) ◽  
pp. 552-556 ◽  
Author(s):  
Andrei Rar ◽  
G.M. Pharr ◽  
W.C. Oliver ◽  
E. Karapetian ◽  
Sergei V. Kalinin

Piezoelectric nanoindentation (PNI) has been developed to quantitatively address electromechanical coupling and pressure-induced dynamic phenomena in ferroelectric materials on the nanoscale. In PNI, an oscillating voltage is applied between the back side of the sample and the indenter tip, and the first harmonic of bias-induced surface displacement at the area of indenter contact is detected. PNI is implemented using a standard nanoindentation system equipped with a continuous stiffness measurement system. The piezoresponse of polycrystalline lead zirconate titanate (PZT) and BaTiO3 piezoceramics was studied during a standard nanoindentation experiment. For PZT, the response was found to be load independent, in agreement with theoretical predictions. In polycrystalline barium titanate, a load dependence of the piezoresponse was observed. The potential of piezoelectric nanoindentation for studies of phase transitions and local structure-property relations in piezoelectric materials is discussed.


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