A novel stable nanopositioner based on a single piezoelectric stack: PistolDrive

We describe a novel stable piezoelectric nanopositioner which just use one piezoelectric stack and one simple driving signal, in which the central shaft is clamped by one BeCu spring and four SiN balls that bonded to the inner wall of the cylindrical tube. The cylindrical tube is fixed on the free end of the piezoelectric stack. Applying one increasing voltage signal on the piezoelectric stack, according to the principle of piezoelectricity, the piezoelectric stack will extend smoothly. When canceling this voltage signal suddenly, the piezoelectric will recover to its original length while the central shaft will keep stationary for its inertance. So, the central shaft will be sliding a small distance relative to the piezoelectric stack. Normally, the heavier of the central shaft, the better moving stability, resulting in a high output force of the nanopositioner. Because of the simple structure, simple working principle and good mechanical stability, our novel nanopositioner can be easily used in Scanning Probe Microscopy system and Active Optical mirror adjustment system in large scale astronomical telescope

A Simple Stable Inertial Nanopositioner with Piezoelectric Stacks

To build a simple and stable nanopositioner which can reduce the complexity of the scanning probe microscopy (SPM) system, a novel inertial nanopositioner with piezoelectric stacks is present ed. The nanopositioner adopts two piezoelectric stacks and one sawtooth driving signal to achieve movement. The two piezoelectric stacks are set in the adjustable direction, and are then fixed on the base. The insulated rail is fixed between the free sides of the two piezoelectric stacks, and the central shaft is pressed by four SiN balls and one CuBe spring in the insulated rail. By applying one sawtooth wave on the piezoelectric stacks, the insulated rail can drive the central shaft to move a nanometer in distance due to its inertance. Experimental results indicate that the nanopositioner can realize nanometer precision fine-tuning and centimeter range coarse adjustment in any direction. The nanopositioner enjoys high compactness and excellent mechanical stability, so it can be easily implanted into precision optical systems and SPM systems. 摘要: 为了搭建出结构简单、性能稳定的纳米步进马达,从而降低扫描探针显微镜系统搭建的复杂度,本文描述 了一款新型的基于压电堆找的惯性纳米步进马达.仅利用两组压电堆我和一路锯齿波电压信号即可实现该马达的 纳米级步进.其中,两组压电堆我按照伸缩方向平行固定于基座上,绝缘导轨粘接固定于两组压电堆我自由端的中 间,利用4 个氮化硅圆球和钦铜弹簧片将滑杆通过挤压方式固定于绝缘导轨内侧.通过给两组压电堆我施加一路 锯齿波电压信号,利用滑杆自身的惯性作用,即可控制绝缘导轨带动滑杆产生纳米级步进.实验结果表明,此款惯 性纳米步进马达可以实现任意角度的纳米级精度位置微调和厘米级范围的粗调.此款纳米步进马达结构紧凑,工 作性能稳定,非常适合于在精密光学系统和极端条件下的扫描探针显微镜系统中使用.中图分类号: TH7 文献标志码:A 文章编号: 1672-6030(2018)01-0023-05 Keywords: nanopositioner, piezoelectric stacks, inertance, sawtooth wave, 关键词: 纳米步进马达, 压电堆校, 惯性, 锯齿

A Novel Intelligent Rebound Hammer System Based on Internet of Things

In order to improve the test efficiency of concrete strength and ensure measured data reliability, we present a novel intelligent rebound hammer system which is based on the Internet of Things (IoT) and speech recognition technology. The system uses a STM32F103C8T6 microcontroller as the Main Control Unit (MCU), and one BC26 module as the communication unit, combined with a LD3320 voice recognition module and TOF050H laser ranging sensor to achieve the function of phonetic transcription and laser ranging. Without the need for traditional multi-person collaboration and burdensome data transfer, the system can collect the data of rebound value and location information and send them to the remote cloud information management system automatically in real time. The test results show that the system has high measuring accuracy, good data transmission stability and convenient operation, which could provide guidance for other types of non-destructive testing equipment designs

Low frequency acoustic energy harvester based on a planar Helmholtz resonator

A novel acoustic energy harvester (AEH) based on an acoustic Helmholtz resonator is proposed in this research to harvest low frequency acoustic energy. The height of the resonator is deep subwavelength of the interesting sound wave, meaning that the overall structure is compact. The neck component is designed as tapered form, specifically to reduce the influence of acoustic resistance. The proposed Helmholtz resonator was evaluated using numerical simulation and experimental tests. In the comparison experiment, the proposed acoustic resonator is compared with an acoustic resonator with uniform neck configuration, and the measured results show the proposed structure can amplify low frequency sound effectively and the resonance frequency corresponds well with the numerical simulation. A PZT-5H piezoelectric patch, bonded to the top side of the AEH, is used to convert mechanical strain energy into electrical power. Experimental results illustrate that under 100 dB SPL excitation, maximum 27.2 μW power can be harvested at 217 Hz and maximum 64.4 μW power can be harvested at 341 Hz. These results correspond to acoustic and mechanical resonance respectively