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Herman Vercruysse, Ramon Sieira-Gil, Alfons Navarro, Eloy Garcia-Diez
BACKGROUND: Midface advancement is a keystone intervention in the treatment plan of syndromic hypoplasia of the midface. Although earlier authors had been using a combination of smaller incisions to acquire enough access to perform the different osteotomies, Tessier popularized the bicoronal incision. This approach can be time-consuming however and leaves an ear-to-ear scar. The authors describe an endoscopically assisted piezo-electric Le Fort III osteotomy performed through minimal invasive access...
December 5, 2016: Journal of Craniofacial Surgery
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
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
Dong K Shin, Bryce M Henson, Roman I Khakimov, Jacob A Ross, Colin J Dedman, Sean S Hodgman, Kenneth G H Baldwin, Andrew G Truscott
We have developed and characterised a stable, narrow linewidth external-cavity laser (ECL) tunable over 100 nm around 1080 nm, using a single-angled-facet gain chip. We propose the ECL as a low-cost, high-performance alternative to fibre and diode lasers in this wavelength range and demonstrate its capability through the spectroscopy of metastable helium. Within the coarse tuning range, the wavelength can be continuously tuned over 30 pm (7.8 GHz) without mode-hopping and modulated with bandwidths up to 3 kHz (piezo) and 37(3) kHz (current)...
November 28, 2016: Optics Express
Yoko Takahashi, Masaki Iwasaki, Atsuhiro Nakagawa, Shiho Sato, Nobukazu Nakasato, Teiji Tominaga
Background The piezo actuator-driven pulsed water jet (ADPJ) system is a novel surgical instrument that enables dissection of tissue without thermal damage. Using the ADPJ system in epilepsy surgery requires prediction of the tissue breaking strength of the epileptic brain. The aim of this study was to elucidate whether magnetic resonance imaging T2 relaxometry could predict the breaking strength. Methods A total of 12 patients with drug-resistant temporal lobe epilepsy who received surgical treatment were included in the study...
November 30, 2016: Journal of Neurological Surgery. Part A, Central European Neurosurgery
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
Kaushik Subramanian, Ilan Gabay, Onur Ferhanoğlu, Adam Shadfan, Michal Pawlowski, Ye Wang, Tomasz Tkaczyk, Adela Ben-Yakar
We present the development of a 5 mm, piezo-actuated, ultrafast laser scalpel for fast tissue microsurgery. Delivery of micro-Joules level energies to the tissue was made possible by a large, 31 μm, air-cored inhibited-coupling Kagome fiber. We overcome the fiber's low NA by using lenses made of high refractive index ZnS, which produced an optimal focusing condition with 0.23 NA objective. The optical design achieved a focused laser spot size of 4.5 μm diameter covering a 75 × 75 μm(2) scan area in a miniaturized setting...
November 1, 2016: Biomedical Optics Express
B G Mytsyk, N M Demyanyshyn, I M Solskii, O M Sakharuk
A general equation describing the rotation of an optical indicatrix of tetragonal crystals (4, 4¯, 4/m symmetry classes) around the X<sub>3</sub> axis (optical axis) depending on the direction of uniaxial pressure in the plane perpendicular to crystal optical axis is written. Partial cases of the general equation, when pressure is acting along the X<sub>1</sub> (X<sub>2</sub>) axis or along the diagonal between the X<sub>1</sub> and X<sub>2</sub> axes, are received...
November 10, 2016: Applied Optics
Stephen R Okoniewski, Ashley R Carter, Thomas T Perkins
Optical traps can measure bead motions with Å-scale precision. However, using this level of precision to infer 1-bp motion of molecular motors along DNA is difficult, since a variety of noise sources degrade instrumental stability. In this chapter, we detail how to improve instrumental stability by (1) minimizing laser pointing, mode, polarization, and intensity noise using an acousto-optical-modulator mediated feedback loop and (2) minimizing sample motion relative to the optical trap using a three-axis piezo-electric-stage mediated feedback loop...
2017: Methods in Molecular Biology
Ruhma Syeda, Maria N Florendo, Charles D Cox, Jennifer M Kefauver, Jose S Santos, Boris Martinac, Ardem Patapoutian
The conversion of mechanical force to chemical signals is critical for many biological processes, including the senses of touch, pain, and hearing. Mechanosensitive ion channels play a key role in sensing the mechanical stimuli experienced by various cell types and are present in organisms from bacteria to mammals. Bacterial mechanosensitive channels are characterized thoroughly, but less is known about their counterparts in vertebrates. Piezos have been recently established as ion channels required for mechanotransduction in disparate cell types in vitro and in vivo...
November 8, 2016: Cell Reports
Moritz Stürmer, Matthias C Wapler, Jana Schmitt, Friedemann Völklein, Ulrike Wallrabe
We present a new principle for tuning the diffraction efficiency of an optical grating and its implementation in a micro-optical device. The overlap of two phase gratings is used to vary the effective phase shift and hence the diffraction efficiency. We study the working principle using Fourier Optics to simulate the diffraction pattern in the far field and design and realize a device based on integrated piezo actuation. We find good agreement between simulation and experiment and observe a suppression of the first diffraction order intensity by more than 97% and response times of less than 3 ms...
October 17, 2016: Optics Express
Ralph E F Lindeboom, Seung Gu Shin, Jan Weijma, Jules B van Lier, Caroline M Plugge
BACKGROUND: It is known that a part of natural gas is produced by biogenic degradation of organic matter, but the microbial pathways resulting in the formation of pressurized gas fields remain unknown. Autogeneration of biogas pressure of up to 20 bar has been shown to improve the quality of biogas to the level of biogenic natural gas as the fraction of CO2 decreased. Still, the pCO2 is higher compared to atmospheric digestion and this may affect the process in several ways. In this work, we investigated the effect of elevated pCO2 of up to 0...
2016: Biotechnology for Biofuels
Xiaoxiao Dong, Tao Yuan, Minqiang Hu, Husain Shekhani, Yuichi Maida, Tonshaku Tou, Kenji Uchino
Piezoelectric transducers are commonly operated at their resonance frequency. However, from a power dissipation standpoint, this is not the ideal driving frequency. In this paper, an optimized driving frequency in between the resonance and antiresonance frequencies is proposed for the piezo-transducer. First, the optimum driving frequency is characterized using a constant vibration velocity measurement method. The actual input power reveals the lowest power dissipation frequency between the resonance and the antiresonance frequencies, where the transducer behaves inductive...
October 2016: Review of Scientific Instruments
Fábio Luis Marques Dos Santos, Bart Peeters
This paper discusses the use of optical fiber Bragg grating (FBG) and piezo strain sensors for structural dynamic measurements. For certain industrial applications, there is an interest to use strain sensors rather than in combination with accelerometers for experimental modal analysis. Classical electrical strain gauges can be used hereto, but other types of strain sensors are an interesting alternative with some very specific advantages. This work gives an overview of two types of dynamic strain sensors, applied to two industrial applications (a helicopter main rotor blade and an F-16 aircraft), FBG sensors and dynamic piezo strain sensors, discussing their use and benefits...
October 2016: Review of Scientific Instruments
Wu-Le Zhu, Zhiwei Zhu, Yi Shi, Xiangfan Chen, Yu He, Kornel F Ehmann, Bing-Feng Ju
This article presents a novel two-degrees-of-freedom (2-DoF) piezo-actuated parallel-kinematic micro/nano-positioning stage with multi-level amplification. The mirror symmetric stage consists of four leverage mechanisms, two Scott-Russell mechanisms, and a Z-shaped flexure hinge (ZFH) mechanism. Taking advantage of the ZFH mechanism, 2-DoF motions with final-level flexural amplification and decoupled motion guidance are achieved. Analytical models of the stage are developed and validated through finite element analysis to characterize its working performance...
October 2016: Review of Scientific Instruments
John P Sutter, Simon G Alcock, Yogesh Kashyap, Ioana Nistea, Hongchang Wang, Kawal Sawhney
Beam shaping is becoming increasingly important for synchrotron X-ray applications. Although routine for visible light lasers, this is challenging for X-rays due to the limited source coherence and extreme optical tolerances required for the shaping mirrors. In deliberate defocusing, even surface errors <5 nm r.m.s. introduce damagingly large striations into the reflected beam. To counteract such problems, surface modifications with alternating concave and convex curvature on equal segments were polished onto the surface of non-active mirrors of fixed curvature...
November 1, 2016: Journal of Synchrotron Radiation
Masato Hoshino, Kentaro Uesugi, Naoto Yagi
X-ray phase contrast tomography based on a grating interferometer was applied to fast and dynamic measurements of biological samples. To achieve this, the scanning procedure in the tomographic scan was improved. A triangle-shaped voltage signal from a waveform generator to a Piezo stage was used for the fast phase stepping in the grating interferometer. In addition, an optical fiber coupled x-ray scientific CMOS camera was used to achieve fast and highly efficient image acquisitions. These optimizations made it possible to perform an x-ray phase contrast tomographic measurement within an 8 min scan with density resolution of 2...
September 2016: Review of Scientific Instruments
Johan U Lind, Travis A Busbee, Alexander D Valentine, Francesco S Pasqualini, Hongyan Yuan, Moran Yadid, Sung-Jin Park, Arda Kotikian, Alexander P Nesmith, Patrick H Campbell, Joost J Vlassak, Jennifer A Lewis, Kevin K Parker
Biomedical research has relied on animal studies and conventional cell cultures for decades. Recently, microphysiological systems (MPS), also known as organs-on-chips, that recapitulate the structure and function of native tissues in vitro, have emerged as a promising alternative. However, current MPS typically lack integrated sensors and their fabrication requires multi-step lithographic processes. Here, we introduce a facile route for fabricating a new class of instrumented cardiac microphysiological devices via multimaterial three-dimensional (3D) printing...
October 24, 2016: Nature Materials
W Montes-Quiroz, F Baillon, O Louisnard, B Boyer, F Espitalier
A single bubble oscillating in a levitation cell is acoustically monitored by a piezo-ceramics microphone glued on the cell external wall. The correlation of the filtered signal recorded over distant cycles on one hand, and its harmonic content on the other hand, are shown to carry rich information on the bubble stability and existence. For example, the harmonic content of the signal is shown to increase drastically once air is fully dissociated in the bubble, and the resulting pure argon bubble enters into the upper branch of the sonoluminescence regime...
March 2017: Ultrasonics Sonochemistry
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