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Astrid Peschel, Andreas Böttcher, Arne Langhoff, Diethelm Johannsmann
Using a temperature-responsive polymer film as an example, it was shown that a conventional quartz crystal microbalance (QCM) can probe a sample's electrical properties in addition to its thickness and softness. The film's electrical impedance was accessed by alternating between the driving voltage being applied to the front electrode and the back electrode. The opposing electrode was grounded in both cases. In the first configuration, the electrical properties of the sample do have an influence on the resonance frequency because of piezoelectric stiffening...
November 2016: Review of Scientific Instruments
Zhen Liu, Zhiyuan Yao, Xiang Li, Qianwei Fu
In this contribution, we propose a novel linear piezoelectric motor with a compact stator that is driven by a single mode. The linear piezoelectric motor can realize bidirectional motion by changing the vibration modes of the stator. Finite element analysis is performed to determine the required vibration mode of the stator and obtain the optimal stator structure and dimensions. Furthermore, the trajectories of the driving foot are analyzed with and without consideration of the mechanical contact with the slider...
November 2016: Review of Scientific Instruments
Weilin Chen, Xianmin Zhang, Sergej Fatikow
For the piezo-driven microgripper, one issue is to enlarge the grasping stroke and realize parallel grasping movement in the compact design. Piezoelectric stack actuator (PSA) and piezoelectric cantilever actuator (PCA) are two kinds of typical piezoelectric actuators. In this study, a novel microgripper hybrid driven by a PSA and two PCAs is proposed, which can be a better solution for the issue, compared with the previous microgripper using PSA-driven multi-stages displacement amplification mechanism (DAM) or using longer and narrower PCAs...
November 2016: Review of Scientific Instruments
Yuting Ma, Minkyu Choi, Kenji Uchino
A compact ultrasonic motor using sandwiching piezo-ceramic plates was developed, having advantages of low manufacturing costs, simple driving circuit, and high scalability. The stator is composed of two piezoelectric plates attached to a T-shaped steel body. Two orthogonal bending modes can be excited by driving one piezoelectric plate and the reversed motion of the rotor can be obtained by driving the piezoelectric plate on the opposite side. The prototype stator with a size of 15 mm × 2.44 mm × 2 mm, operated at 44...
November 2016: Review of Scientific Instruments
Chung Ming Leung, Ya Wang, Wusi Chen
In this letter, the airfoil-based electromagnetic energy harvester containing parallel array motion between moving coil and trajectory matching multi-pole magnets was investigated. The magnets were aligned in an alternatively magnetized formation of 6 magnets to explore enhanced power density. In particular, the magnet array was positioned in parallel to the trajectory of the tip coil within its tip deflection span. The finite element simulations of the magnetic flux density and induced voltages at an open circuit condition were studied to find the maximum number of alternatively magnetized magnets that was required for the proposed energy harvester...
November 2016: Review of Scientific Instruments
A Hosokawa
In this study, piezoelectric cells (PE-cells) of cancellous bone were experimentally produced to receive an ultrasound wave. In the PE-cell, a bovine cancellous bone specimen, in which the pore spaces were saturated with air, was electrically shielded to prevent electromagnetic noise. As a result, the piezoelectric signal generated in the cancellous bone specimen by irradiating an ultrasound burst wave at 1.0 MHz could be clearly observed in water. The experimental results showed that the ultrasound sensitivity per unit area of cancellous bone was estimated to be below 1/100 and 1/100 000 of cortical bone and poly(vinylidene fluoride), respectively...
November 2016: Journal of the Acoustical Society of America
Ahmed Allam, Adel Elsabbagh, Wael Akl
A two-dimensional active acoustic metamaterial with controllable anisotropic density is introduced. The material consists of composite lead-lead zirconate titanate plates clamped to an aluminum structure with air as the background fluid. The effective anisotropic density of the material is controlled, independently for two orthogonal directions, by means of an external static electric voltage signal. The material is used in the construction of a reconfigurable waveguide capable of controlling the direction of the acoustic waves propagating through it...
November 2016: Journal of the Acoustical Society of America
Murielle Vanessa Tchakui, Paul Woafo
This work deals with the dynamics of three unidirectionally coupled Duffing oscillators and that of three coupled piezoelectric actuators, considering the special case of inchworm motors. Two configurations of the network are studied: ring configuration and chain configuration. The effects of the coupling coefficient and the time delay are analyzed through different bifurcation diagrams and phase difference variation. It is shown that varying the coupling coefficient and the time delay leads to the appearance of different dynamical behaviors: steady states, periodic and quasiperiodic oscillations, chaos, and phase synchronization...
November 2016: Chaos
Emre Tosun, Meric Bilgiç, Benay Yildirim, Hakan Hifzi Tüz, Taha Özer
The aim of this study is to compare the bone healing in the distraction gap following the osteotomy performed with piezoelectric and conventional devices for the distraction osteogenesis in the rabbit mandibles. Twelve rabbits were randomly divided into 2 groups; 6 for piezoelectric device and 6 for rotary instruments. After 3 days of latency period, distraction was started at a rate of 1 mm per day for 10 days. All the animals were sacrificed after 4 weeks of consolidation phase for histological and histomorphological evaluation...
November 30, 2016: Journal of Craniofacial Surgery
Jie-Su Wang, Kui-Juan Jin, Hai-Zhong Guo, Jun-Xing Gu, Qian Wan, Xu He, Xiao-Long Li, Xiu-Lai Xu, Guo-Zhen Yang
BiFeO3 thin films have drawn much attention due to its potential applications for novel magnetoelectric devices and fundamental physics in magnetoelectric coupling. However, the structural evolution of BiFeO3 films with thickness remains controversial. Here we use an optical second-harmonic generation technique to explore the phase-related symmetry evolution of BiFeO3 thin films with the variation of thickness. The crystalline structures for 60 and 180-nm-thick BiFeO3 thin films were characterized by high-resolution X-ray diffractometry reciprocal space mapping and the local piezoelectric response for 60-nm-thick BiFeO3 thin films was characterized by piezoresponse force microscopy...
December 1, 2016: Scientific Reports
Dhiren K Pradhan, Shalini Kumari, Venkata S Puli, Proloy T Das, Dillip K Pradhan, Ashok Kumar, J F Scott, Ram S Katiyar
Multiferroic composite structures, i.e., composites of magnetostrictive and piezoelectric materials, can be envisioned to achieve the goal of strong room-temperature ME coupling for real practical device applications. Magnetic materials with high magnetostriction, high Néel temperature (TN), high resistivity and large magnetization are required to observe high ME coupling in composite structures. In continuation of our investigations on suitable magnetic candidates for multiferroic composite structures, we have studied the crystal structure, dielectric, transport, and magnetic properties of Co0...
November 30, 2016: Physical Chemistry Chemical Physics: PCCP
Moumita Dutta, Soutik Betal, Xomalin G Peralta, Amar S Bhalla, Ruyan Guo
Phase modulators are one of the key components of many applications in electromagnetic and opto-electric wave propagations. Phase-shifters play an integral role in communications, imaging and in coherent material excitations. In order to realize the terahertz (THz) electromagnetic spectrum as a fully-functional bandwidth, the development of a family of efficient THz phase modulators is needed. Although there have been quite a few attempts to implement THz phase modulators based on quantum-well structures, liquid crystals, or meta-materials, significantly improved sensitivity and dynamic control for phase modulation, as we believe can be enabled by piezoelectric-resonance devices, is yet to be investigated...
November 30, 2016: Scientific Reports
Liang Wang, Chengyou Shu, Quan Zhang, Jiamei Jin
In this paper, a novel sandwich-type traveling wave piezoelectric tracked mobile system was proposed, designed, fabricated and experimentally investigated. The proposed system exhibits the advantages of simple structure, high mechanical integration, lack of electromagnetic interference, and lack of lubrication requirement, and hence shows potential application to robotic rovers for planetary exploration. The tracked mobile system is comprised of a sandwich actuating mechanism and a metal track. The actuating mechanism includes a sandwich piezoelectric transducer and two annular parts symmetrically placed at either end of the transducer, while the metal track is tensioned along the outer surfaces of the annular parts...
November 15, 2016: Ultrasonics
Guangqing Wang, Wentan Xu, Shuaishuai Gao, Binqiang Yang, Guoli Lu
An energy harvesting type ultrasonic motor is presented in this work. The novel motor not only can drive and/or position the motion mechanism, but also can harvest and convert the vibration-induced energy of the stator into electric energy to power small electronic devices. In the new motor, the stator is a sandwich structure of two PZT rings and an elastic metal body. The PZT ring bonded on the bottom surface is used to excite the stator metal body to generate a traveling wave with converse piezoelectric effect, and the other PZT ring bonded on top surface is used to harvest and convert the vibration-induced energy of the stator into electric energy with direct piezoelectric effect...
November 16, 2016: Ultrasonics
Xiaolong Lu, Junhui Hu, Hanmin Peng, Yuan Wang
In this paper, a new topological structure for the Langevin-type ultrasonic transducer is proposed and investigated. The two cylindrical terminal blocks are conically shaped with four supporting plates each, and two cooling fins are disposed at the bottom of terminal blocks, adjacent to the piezoelectric rings. Experimental results show that it has larger vibration velocity, lower temperature rise and higher electroacoustic energy efficiency than the conventional Langevin transducer. The reasons for the phenomena can be well explained by the change of mass, heat dissipation surface and force factor of the transducer...
November 16, 2016: Ultrasonics
Md Mehebub Alam, Sujoy Kumar Ghosh, Debabrata Sarkar, Shrabanee Sen, Dipankar Mandal
Titanium dioxide (TiO2) nanoparticles (NPs) embedded γ-phase containing polyvinylidene fluoride (PVDF) nanocomposite (PNC) film turns to an excellent material for energy storage application due to an increased dielectric constant (32 at 1 kHz), enhanced electric breakdown strength (400 MV m(-1)). It also exhibits a high energy density of 4 J cm(-3) which is 25 times higher than that of virgin PVDF. 98% of the electroactive γ-phase has been acheived by the incorporation of TiO2 NPs and the resulting PNC behaves like a super-toughened material due to a dramatic improvement (more than 80%) in the tensile strength...
November 29, 2016: Nanotechnology
Adrien Michel, Romain Bosc, Jean-Paul Meningaud, Philippe Hernigou, Guillaume Haiat
BACKGROUND: The primary stability of the acetabular cup (AC) implant is an important determinant for the long term success of cementless hip surgery. However, it remains difficult to assess the AC implant stability due to the complex nature of the bone-implant interface. A compromise should be found when inserting the AC implant in order to obtain a sufficient implant stability without risking bone fracture. The aim of this study is to evaluate the potential of impact signals analyses to assess the primary stability of AC implants inserted in cadaveric specimens...
2016: PloS One
Noelle M do Nascimento, Augusto Juste-Dolz, Elena Grau-García, Jose A Román-Ivorra, Rosa Puchades, Angel Maquieira, Sergi Morais, David Gimenez-Romero
An autoantigen piezoelectric sensor to quantify specific circulating autoantibodies in human serum is developed. The sensor consisted on a quartz crystal microbalance with dissipation monitoring (QCM-D) where TRIM21 and TROVE2 autoantigens were covalently immobilized, allowing the selective determination of autoantibodies for diagnosis and prognosis of Systemic Lupus Erythematosus (SLE). The sensitivity of the biosensor, measured as IC50 value, was 1.51U/mL and 0.32U/mL, for anti-TRIM21 and anti-TROVE2 circulating autoantibodies, respectively...
November 9, 2016: Biosensors & Bioelectronics
Chao Li, Lingyan Wang, Zhao Wang, Yaodong Yang, Wei Ren, Guang Yang
Oxide interface engineering has attracted considerable attention since the discovery of its exotic properties induced by lattice strain, dislocation and composition change at the interface. In this paper, the atomic resolution structure and composition of the interface between the lead-free piezoelectric (K0.5Na0.5)NbO3 (KNN) thin films and single-crystalline SrTiO3 substrate were investigated by means of scanning transmission electron microscopy (STEM) combining with electron energy loss spectroscopy (EELS)...
November 25, 2016: Scientific Reports
Xiao Tan, Markku Alén, Kun Wang, Jarkko Tenhunen, Petri Wiklund, Markku Partinen, Sulin Cheng
Growing evidence suggests that diet alteration affects sleep, but this has not yet been studied in adults with insomnia symptoms. We aimed to determine the effect of a six-month diet intervention on sleep among overweight and obese (Body mass index, BMI ≥ 25 kg/m²) men with chronic insomnia symptoms. Forty-nine men aged 30-65 years with chronic insomnia symptoms were randomized into diet (n = 28) or control (n = 21) groups. The diet group underwent a six-month individualized diet intervention with three face-to-face counseling sessions and online supervision 1-3 times per week; 300-500 kcal/day less energy intake and optimized nutrient composition were recommended...
November 23, 2016: Nutrients
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