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We have developed a piezoelectric thin film from shrimp and crab shells, after demineralizing the shells and removing the minerals to create a flexible, transparent film. The dried piezoelectric thin film plated between copper electrodes contains a piezoelectric harvesting circuit that stores energy derived from the shells. A rectifier circuit is connected to this experimental set up and output is observed in order to find output how the energy is extracted from the crustacean shells. This process makes the energy an eco-friendly source of energy. The flexibility of processed crustacean film such as shrimp and crab shells will be important in energy harvesting devices. [ABSTRACT FROM AUTHOR]

Aluminum Nitride (AlN) is a piezoelectric material that has recently gained attention for CMOS (complementary metal-oxide semiconductor) compatible MEMS devices. In this report we report on the growth of AlN deposited on glass and silicon (111) at room temperature (CMOS compatible) using reactive DC magnetron sputtering. Sputtering is done at a low sputtering power of 30 W with different gas flow rates to minimize the residual stresses. The variation of the film properties is studied in comparison with the change in the flow rate of gas. A distinct change in the orientation from the (100) to (101) plane is observed through XRD analysis. The surface morphology of deposited films has been analyzed using SEM and EDX analysis is done to confirm the composition of the films. [ABSTRACT FROM AUTHOR]

In this work, we report the advantages of following a protocol to perform measurements of piezoresponse force microscopy (PFM) away from the tip-sample contact resonance. The protocol established in this work is based on Soergel's work [J. Phys. D: Appl. Phys. 44 (2011) 464003]. PFM measurements out-of-plane were carried out in the range of 10-100 kHz. The experimental background, that affects the domain contrast during PFM measurements, was reduced by analyzing the X-signal from the lock-in amplifier (LIA) during a frequency sweep measurement on a glass slide (non-piezoelectric). Optimal contrast in X-signal was attained through set the phase of the LIA to reach a null contrast in the Y-signal. Then, the X-Y and R-Θ signals are stored using the optimal conditions established for LIA. The protocol described was applied to a sol-gel BiFeO3 film and a reference sample of periodically poled lithium niobate. [ABSTRACT FROM AUTHOR]

Film bulk acoustic wave resonator (FBAR) is a device that consists of a thin-film piezoelectric, which is sandwiched between the top and bottom electrodes. FBAR has been widely used in radio frequency (RF) front-end circuits such as RF filters due to its advantages of high quality (Q) factor. The performance of FBAR is highly related to the piezoelectric material. The piezoelectric material such as aluminum nitride (AlN) and zinc oxide (ZnO) are commonly used in FBAR. Other than piezoelectric material, another important element in designing an FBAR is the electrode materials. Different electrode materials affect the performance of FBAR in terms of Q factor and electromechanical coupling coefficient (k2eff) due to their material properties. Therefore, in this work, FBARs operating at frequencies of 5 GHz to 10 GHz by using AlN as the piezoelectric material with different electrode materials, which are molybdenum (Mo) and aluminum (Al) were designed. The performance of the designed FBARs were compared in terms of Q factor and k2eff. Based on the results, the Q factor of FBAR with Mo as electrodes achieved the highest value of 16300 at 5 GHz, while the Q factor of FBAR with Al as electrodes achieved the highest value of 13726 at 5 GHz. The k2eff of FBAR with Al as electrodes achieved the highest value of 6.71% at 7 GHz, while FBAR with Mo as electrodes achieved the highest coupling coefficient of 5.78% at 6 GHz. [ABSTRACT FROM AUTHOR]

Mechanical vibrations are abundantly available energy devoid of any environmental conditions. Polyvinylidene fluoride (PVDF), a piezoelectric property can be used to harvest this freely available energy to convert into useful electrical energy. In the present work, the piezoelectric property of PVDF has been enhanced by incorporating BaTiO3 rods into it. The enhancement in the piezoelectric phase (β-phase) of PVDF has been reported in this work, and the piezoelectric nanogenerator (PENG) fabricated from BaTiO3-PVDF gives a voltage of ∼2V and current of ∼0.31 µA. [ABSTRACT FROM AUTHOR]

The amplification of acoustic wave generated by coupling between plasmons and acoustic phonons in piezoelectric semiconductor plasma is examined using quantum hydrodynamic model. The present study takes care of quantum effects like Fermi degenerate pressure and Bohm potential through quantum parameter- H. a modified dispersion relation is derived for evolution of acoustic wave by employing the linearization technique. An expression for gain coefficient of acoustic wave is obtained in terms of quantum parameter- H under collision dominated limit. The growth rate of the wave is analyzed by varying the parameters like doping concentration 0 n and angular frequency ω for different piezoelectric semiconductors. This study seeks its application in designing of many electronic devices such as acoustic wave amplifier, acousto-electric oscillators, acoustic filters etc. [ABSTRACT FROM AUTHOR]

In this paper free vibration of functionally graded piezoelectric circular plate is studied for fixed-fixed boundary condition. Elastic stiffness, piezoelectric and dielectric coefficient of plate vary continuously along the thickness of the plate by using power law. Material properties of FGPM plate varies from PZT-5H to PZT-4. Bottom surface of FGPM plate is PZT-5H and top surface is PZT-4 rich. Top and bottom surface of plate is kept grounded. FGPM annular plate is polarised in radial direction. Here, shear effect is also produced by using d15 coupling coefficient. Free vibration is analysed for different-different geometrical parameters. In the present age functionally graded piezoelectric material is widely used in making smart devices, sensor, actuators, ultrasonic motor, MEMS. This present research is very useful for developing existing application and developing new ones utilizing the FGPM annular plate. [ABSTRACT FROM AUTHOR]

We demonstrate the effect of parallel and antiparallel orientations of spontaneous and piezoelectric polarizations upon the I-V characteristics of vertical metal/GaN/AlGaN/GaN heterostructures. Unlike in the generally accepted model considering parallel orientation of piezoelectric and spontaneous polarization, we achieved reasonable agreement between simulations and experiment only on assuming antiparallel orientation of the two kinds of polarization. [ABSTRACT FROM AUTHOR]

Field testing of structures at high-temperature is a challenge as commercial transducer are not rated for such high-temperatures. There is an increased interest in the use of film transducers for the testing of materials. With the diminishing size in everyday objects, the systems incorporated to monitor them also need to decrease in size. The complexity of the model is an added reason for the rise of this technology. Film coatings have served various purposes in the field of NDE. Previous work has been performed using sol-gel, potato starch and PZT as the piezoelectric material, but due to their individual disadvantages, other inorganic materials were studied. This transducer consists of a piezoceramic film composed of Bismuth Titanate and a high-temperature inorganic binding agent, Ceramabind 830. A thick film forms on the substrate which is then poled in an electric field to impart piezoelectricity in the film. Pulse-echo measurements for signal voltage over a certain period of time are made to validate its workability. The films were tested to elevated temperatures and a guided-wave system is currently being studied to provide in-situ monitoring for pipes and rod like structures. [ABSTRACT FROM AUTHOR]

In the present age functionally graded piezoelectric materials (FGPM) are increasingly being used as actuators and sensors. In spite of the fact that the piezoelectric coupling coefficient for shear d15 has much higher value in comparison to d31 or d33, it is far less utilized for the applications due to complex nature of the shear induced vibrations. In this work three dimensional free vibration analysis of functionally graded piezoelectric material annular plates with free-free boundary conditions is presented. The annular FGPM plate is polarized along the radial direction while the electric field is applied along the thickness direction inducing flexural vibrations of the plate due to d15 effect of functionally graded piezoelectric materials. The material properties are assumed to have a power law variation along the thickness. COMSOL Multiphysics is used to obtain the natural frequencies and modeshapes. Detailed numerical study is performed to ascertain the effect of variation in power law index and various geometrical parameters. The results presented shall be helpful in optimizing the existing applications and developing the new ones utilizing the FGPM annular plates. [ABSTRACT FROM AUTHOR]

In order to elucidate the effects of nanomechanical stimulation on the regulation of cellular functions, we have been developing a cell culture microdevice integrated with piezoelectric thin film actuators. In this paper, we propose a new geometric configuration of the device to allow cell culture on a relatively flat surface and in an open space. An improved fabrication process for PZT actuators overcame a serious problem that sometimes occurred in the previous process; photoresist patterned on PZT film cannot be completely removed due to its degradation in a dry etching process. Then we demonstrate the driving performance of a fabricated prototype microdevice. Moreover, individual cells can be arranged precisely at the desired positions of the PZT actuators by a positive dielectrophoretic force at frequencies above 100 kHz with an application of an AC voltage of 20 Vpp. The trapping rate was dramatically improved up to 90% by using microchannel to efficiently supply cells onto the surface of the PZT actuator. [ABSTRACT FROM AUTHOR]

This paper describes the measurement of lubricant layer thickness using ultrasound. High frequency (20–200 MHz) ultrasound is excited using a piezoelectric AlN film deposited onto the outer raceway of a rolling element bearing. This sensor allows the interrogation of the small lubricated region between the ball and raceway. The reflection coefficient from the lubricant layer is then measured and the layer thickness extracted via a quasi-static spring model. Good agreement is shown with known lubrication theory. [ABSTRACT FROM AUTHOR]