Read by QxMD icon Read


I A Borodina, B D Zaitsev, A A Teplykh
The influence of the liquid with the different values of conductivity, permittivity, and viscosity on the characteristics of the slot mode in the structure consisting of delay line with propagating shear - horizontal acoustic wave of zero order (SH0) and upper piezoelectric plate separated by the air gap was experimentally investigated. The delay line made of the Y-X lithium niobate plate 0.2mm thick contained two interdigital transducers for the excitation and reception of acoustic wave in the frequency range of 2...
July 18, 2017: Ultrasonics
Hans R G W Verstraete, Morgan Heisler, Myeong Jin Ju, Daniel Wahl, Laurens Bliek, Jeroen Kalkman, Stefano Bonora, Yifan Jian, Michel Verhaegen, Marinko V Sarunic
In this report, which is an international collaboration of OCT, adaptive optics, and control research, we demonstrate the Data-based Online Nonlinear Extremum-seeker (DONE) algorithm to guide the image based optimization for wavefront sensorless adaptive optics (WFSL-AO) OCT for in vivo human retinal imaging. The ocular aberrations were corrected using a multi-actuator adaptive lens after linearization of the hysteresis in the piezoelectric actuators. The DONE algorithm succeeded in drastically improving image quality and the OCT signal intensity, up to a factor seven, while achieving a computational time of 1 ms per iteration, making it applicable for many high speed applications...
April 1, 2017: Biomedical Optics Express
Nobuya Sato, Ryosuke Akashi, Shinji Tsuneyuki
A series of unsynthesized perovskite-type oxyhydrides ATiO2H (A = Li, Na, K, Rb, Cs) are investigated by the density functional calculations. These oxyhydrides are stable in the sense of the formation energies for some possible synthesis reactions. They are crystallized into quite similar crystal structures with the long c-axis, and the corner-sharing TiO4H2 octahedra of the ideal perovskite-type structure are deformed into the 5-fold coordinated titanium atoms with the OH plane and the apical oxygen atoms...
July 21, 2017: Journal of Chemical Physics
Gonzalo Gómez Val, Fernando Jara, Baltasar Sánchez, Miguel Roig, Ricard Ferrer, Fernando Duran-Sindreu
PURPOSE: Evidence-based research appears to conflict on the potential risk of electromagnetic interference (EMI) between piezoelectric units (Pzs) and implantable cardioverters and defibrillators (ICDs). The purpose of this study was to observe whether the EMI produced by Pzs is hazardous for ICDs. MATERIALS AND METHODS: A cross-sectional study of 6 Pzs was conducted in vitro for EMI using an ICD system. To simulate the human body's electrical resistance, electrographic recordings were made of the ICD and lead that were immersed in a bath of saline solution...
June 29, 2017: Journal of Oral and Maxillofacial Surgery
Hui Liu, Jun Chen, Longlong Fan, Yang Ren, Zhao Pan, K V Lalitha, Jürgen Rödel, Xianran Xing
High-performance piezoelectric materials constantly attract interest for both technological applications and fundamental research. The understanding of the origin of the high-performance piezoelectric property remains a challenge mainly due to the lack of direct experimental evidence. We perform in situ high-energy x-ray diffraction combined with 2D geometry scattering technology to reveal the underlying mechanism for the perovskite-type lead-based high-performance piezoelectric materials. The direct structural evidence reveals that the electric-field-driven continuous polarization rotation within the monoclinic plane plays a critical role to achieve the giant piezoelectric response...
July 7, 2017: Physical Review Letters
Hongwei Huang, Shuchen Tu, Chao Zeng, Tierui Zhang, A H Reshak, Yihe Zhang
We report that both efficient photo- and piezoelectric- induced molecular oxygen activation are achieved via macroscopic polarization enhancement on a noncentrosymmetric piezoelectric semiconductor BiOIO3. The replacement of V5+ ions for I5+ in IO3 polyhedra gives rise to strengthened macroscopic polarization of BiOIO3, which facilitates the charge separation in the photocatalytic and piezoelectric-catalytic process, and renders largely promoted photo- and piezoelectric induced reactive oxygen species (ROS) evolution, such as superoxide radicals (*O2-) and hydroxyl radicals (*OH)...
July 21, 2017: Angewandte Chemie
Kumara Cordero-Edwards, Neus Domingo, Amir Abdollahi, Jordi Sort, Gustau Catalan
The mechanical properties of materials are insensitive to space inversion, even when they are crystallographically asymmetric. In practice, this means that turning a piezoelectric crystal upside down or switching the polarization of a ferroelectric should not change its mechanical response. Strain gradients, however, introduce an additional source of asymmetry that has mechanical consequences. Using nanoindentation and contact-resonance force microscopy, this study demonstrates that the mechanical response to indentation of a uniaxial ferroelectric (LiNbO3 ) does change when its polarity is switched, and use this mechanical asymmetry both to quantify its flexoelectricity and to mechanically read the sign of its ferroelectric domains...
July 21, 2017: Advanced Materials
Yu-Meng You, Wei-Qiang Liao, Dewei Zhao, Heng-Yun Ye, Yi Zhang, Qionghua Zhou, Xianghong Niu, Jinlan Wang, Peng-Fei Li, Da-Wei Fu, Zheming Wang, Song Gao, Kunlun Yang, Jun-Ming Liu, Jiangyu Li, Yanfa Yan, Ren-Gen Xiong
Molecular piezoelectrics are highly desirable for their easy and environment-friendly processing, light weight, low processing temperature, and mechanical flexibility. However, although 136 years have passed since the discovery in 1880 of the piezoelectric effect, molecular piezoelectrics with a piezoelectric coefficient d33 comparable with piezoceramics such as barium titanate (BTO; ~190 picocoulombs per newton) have not been found. We show that trimethylchloromethyl ammonium trichloromanganese(II), an organic-inorganic perovskite ferroelectric crystal processed from aqueous solution, has a large d33 of 185 picocoulombs per newton and a high phase-transition temperature of 406 kelvin (K) (16 K above that of BTO)...
July 21, 2017: Science
Nitin Shingne, Markus Geuss, Thomas Thurn-Albrecht, Hans-Werner Schmidt, Carmen Mijangos, Martin Steinhart, Jaime Martin
Because final properties of nanoscale polymeric structures are largely determined by the solid-state microstructure of the confined polymer, it is imperative not only to understand how the microstructure of polymers develops under nanoscale confinement but also to establish means to manipulate it. Here we present a series of processing strategies, adapted from methods used in bulk polymer processing, that allow to control the solidification of polymer materials confined in the nanopores of anodic aluminium oxide (AAO) templates...
July 20, 2017: Journal of Physical Chemistry. B
Qiang Zheng, Bojing Shi, Zhou Li, Zhong Lin Wang
Implantable medical devices (IMDs) have become indispensable medical tools for improving the quality of life and prolonging the patient's lifespan. The minimization and extension of lifetime are main challenges for the development of IMDs. Current innovative research on this topic is focused on internal charging using the energy generated by the physiological environment or natural body activity. To harvest biomechanical energy efficiently, piezoelectric and triboelectric energy harvesters with sophisticated structural and material design have been developed...
July 2017: Advanced Science (Weinheim, Baden-Wurttemberg, Germany)
David Gaddes, William Brian Reeves, Srinivas Tadigadapa
In this work, we demonstrate the quantification of creatinine in human urine samples using a microcalorimetric sensing system. The calorimetric sensor is based on an array of microfabricated Y-cut quartz resonators. The piezoelectric quartz is etched down to a thickness of 10 μm and exhibits a bulk acoustic resonance of 166 MHz. The temperature sensitivity of this high-frequency quartz resonator is 14 600 Hz/K due to the high phenomenological sensitivity of quartz. Most importantly, the quartz sensors and the analyte fluidics are decoupled providing a significantly more robust calorimetric sensing system than directly contacted chip calorimeters...
June 23, 2017: ACS Sensors
Benpeng Zhu, Chunlong Fei, Chen Wang, Yuhang Zhu, Xiaofei Yang, Hairong Zheng, Qifa Zhou, K Kirk Shung
Precise cell positioning is indispensable in the fields of biophysics and cellular biology. Acoustic microbeam produced by a highly focused ultrasound transducer has recently been investigated for a particle or cell manipulation. By virtue of the relatively good piezoelectric property, Sc doped AlN film was introduced for a highly focused ultrasound transducer application. Using a sputtering approach, a self-focused AlScN film based device has been designed, fabricated, and characterized at a frequency of ∼230 MHz...
January 27, 2017: ACS Sensors
Zhen Zhou, Jin Luo, Wei Sun, Jing-Feng Li
Extensive studies on (Bi0.5Na0.5)TiO3-BaTiO3 piezoceramics have aroused growing interest in developing high-performance piezoelectric films based on this promising lead-free piezoelectric system. High quality (1 - x%) (Bi0.5Na0.5)TiO3-x% BaTiO3 (x = 0-15) thin films were synthesized on Pt(111)/Ti/SiO2/Si(100) substrates via a sol-gel method. The phase transitions as functions of composition and temperature were investigated by X-ray diffraction (XRD) and temperature-dependent Raman spectra analysis. A morphotropic phase boundary (MPB) located at 5 ≤ x ≤ 10 was found in the films, being identical to that in bulk materials...
July 19, 2017: Physical Chemistry Chemical Physics: PCCP
Song Mi Lee, Sung-Ho Shin, Junghyo Nah, Min Hyung Lee
Appropriate control of energy band bending at the interface between semiconductors and electrolytes are closely related to performance of photoelectrochemical (PEC) water splitting. Dipoles formed near the surface of semiconductors induces energy band bending at the interface. Energy band bending control has been demonstrated by employing charged molecules and piezoelectric materials. However, chemical and piezoelectric approaches have demerit of chemical instability and inducement of instantaneous dipole, respectively...
July 19, 2017: Nanotechnology
Angela Notarnicola, Florenzo Iannone, Giuseppe Maccagnano, Nuniza Lacarpia, Dorotea Bizzoca, Biagio Moretti
BACKGROUND: Shock wave treatment is used for several orthopedic diseases and there are different devices available. Until now, there have been no experimental studies on the effects of these different generators. METHODS: We carried out an experimental study to compare the effects of three focused generators (electro-magnetic, piezoelectric and electro-hydraulic) as well as a radial generator on healthy and osteoarthritis chondrocytes. RESULTS: By the analysis of our results, we may exclude significant differences between the different generators, even though there is a greater action specificity for electro-magnetic and piezoelectric generators...
January 2017: Muscles, Ligaments and Tendons Journal
S Sivolella, G Brunello, F Fistarol, E Stellini, C Bacci
The aim of this case series study was to illustrate the bone lid technique implemented using piezoelectric surgery to access mandibular alveolar bone diseases and to assess the clinical and radiographic outcomes. The technique was used to treat 21 consecutive patients with various conditions: cysts in six cases, impacted teeth with associated cysts in nine, keratocystic odontogenic tumours in three, impacted teeth in two, and an endodontic lesion in one. The bone lid was fashioned using piezoelectric surgery and a thin osteotomy insert...
July 14, 2017: International Journal of Oral and Maxillofacial Surgery
Ying-Jun Li, Cong Yang, Gui-Cong Wang, Hui Zhang, Huan-Yong Cui, Yong-Liang Zhang
This paper presents a novel integrated piezoelectric six-dimensional force sensor which can realize dynamic measurement of multi-dimensional space load. Firstly, the composition of the sensor, the spatial layout of force-sensitive components, and measurement principle are analyzed and designed. There is no interference of piezoelectric six-dimensional force sensor in theoretical analysis. Based on the principle of actual work and deformation compatibility coherence, this paper deduces the parallel load sharing principle of the piezoelectric six-dimensional force sensor...
July 14, 2017: ISA Transactions
Young-Rae Ko, Yoonkyu Hwang, Minji Chae, Tae-Hyoung Kim
In this study, we present an identification-based direct construction of the inverse generalized Prandtl-Ishlinskii (P-I) model to facilitate inverse model-based feedforward compensation of asymmetric hysteresis nonlinearities. Compared with the derivation of the inverse model analytically from a generalized P-I model, this direct modeling approach has the following advantages. First, direct inverse model identification is formulated as a nonlinear optimization problem, which is not subject to the constraint condition on the generalized P-I model's threshold and density functions, where this is indispensable for the analytical model inversion procedure...
July 14, 2017: ISA Transactions
Thomas L A van den Heuvel, David J Graham, Kristopher J Smith, Chris L de Korte, Jeffrey A Neasham
OBJECTIVE: In this paper, we present the design of low-cost medical ultrasound scanners aimed at the detection of maternal mortality risk factors in developing countries. METHOD: Modern ultrasound scanners typically employ a high element count transducer array with multichannel transmit and receive electronics. To minimize hardware costs, we employ a single piezoelectric element, mechanically swept across the target scene, and a highly cost-engineered single channel acquisition circuit...
July 17, 2017: IEEE Transactions on Biomedical Circuits and Systems
Quan-Liang Zhao, Guang-Ping He, Jie-Jian Di, Wei-Li Song, Zhi-Ling Hou, Pei-Pei Tan, Da-Wei Wang, Mao-Sheng Cao
A flexible semitransparent energy harvester is assembled based on laterally aligned Pb(Zr0.52Ti0.48)O3 (PZT) single-crystal nanowires (NWs). Such a harvester presents the highest open-circuit voltage and a stable area power density of up to 10 V and 0.27 μW/cm(2), respectively. A high pressure sensitivity of 0.14 V/kPa is obtained in the dynamic pressure sensing, much larger than the values reported in other energy harvesters based on piezoelectric single-crystal NWs. Furthermore, theoretical and finite element analyses also confirm that the piezoelectric voltage constant g33 of PZT NWs is competitive to the lead-based bulk single crystals and ceramics, and the enhanced pressure sensitivity and power density are substantially linked to the flexible structure with laterally aligned PZT NWs...
July 17, 2017: ACS Applied Materials & Interfaces
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"