AIN压电振动能量收集器的结构优化设计与实验

在整体尺寸不变的基础上,结合集总参数模型,利用ANSYS有限元软件对氮化铝(AlN)压电振动能量收集器的结构参数进行优化设计,得到压电悬臂梁单元的优化尺寸为5mm×12mm×0.05mm.设计了工艺流程,加工了原理样机.经测试:在1gn加速度,204.6 Hz谐振频率激励下,样机在最优化负载80 kΩ下的输出电压为2.3V,输出功率为66.125μW,满足部分低功耗传感节点的供能要求.     

Power sensitivity of vibration energy harvester

This paper deals with a power sensitivity improvement of an electromagnetic vibration energy harvester which generates electrical energy from ambient vibrations. The harvester provides an autonomous source of energy for wireless applications, with an expected power consumption of several mW, placed in environment excited by ambient mechanical vibrations. An appropriately tuned up design of the harvester with adequate sensitivity provides sufficient generating of electrical energy for some wireless applications and maximal harvested power depends on a harvester mass, frequency and level of the vibration and sensitivity of the energy harvester. The design of our harvester is based on electromagnetic converter and it contains a unique spring-less resonance mechanism where stiffness is provided by repelled magnetic forces. The greater sensitivity of the harvester provides more generated power or decrease of the harvester size and weight.     

Multi-band piezoelectric vibration energy harvester for low-frequency applications

Microsystem Technologies - Piezoelectric Energy Harvester (PEH) is a promising technology for harvesting energy from low frequency ambient vibrations. To generate the power from these low-frequency...     

一种宽频的磁式压电振动能量采集器

基于环境能量采集的压电振动能量采集器为无线传感器和微机电系统的长期供能提供了一种有效解决方案.目前研制的压电式振动能量采集器存在工作频率高,且频带窄的问题.给出了一种通过磁力的引入使其在低频下工作的、宽频的压电振动能量采集器,并搭建了测试系统对器件进行分析测试.在压电悬臂梁上放置永磁铁取代传统的质量块,同时在悬臂梁的上...     

Up-scaled macro-device implementation of a MEMS wideband vibration piezoelectric energy harvester design concept

In this work, we discuss a novel mechanical resonator design for the realisation of vibration Energy Harvester (EH) capable to deliver power levels in the mW range. The device overcomes the typical constraint of frequency narrowband operability of standard cantilevered EHs, by exploiting a circular-shaped resonator with an increased number of mechanical Degrees Of Freedom (DOFs), leading to several resonant modes in the range of vibrations of interest (i.e. multi-modal wideband EH). The device, named Four-Leaf Clover (FLC), is simulated in Ansys Workbench?, showing a significant number of resonant modes up to vibrations of around 2 kHz (modal eigenfrequencies analysis), and exhibiting levels of converted power up to a few mW at resonance (harmonic coupled-field analysis). The FLC mechanical structure, along with cantilevered test structure, is realised by micro-milling of an Aluminium foil. PolyVinyliDene Fluoride (PVDF) film sheet pads are assembled in order to collect first experimental feedback on generated power levels. The FLC and cantilevered EH test structures are characterised experimentally with a measurement setup purposely developed, showing encouraging performance related to the technology chosen for the realisation of EH, thus paving the way for full validation of the macro-FLC concept.     

A magnetoelectric-based broadband vibration energy harvester for powering wireless sensors

Scavenging vibration energy directly from environments is an attractive technique for potentially powering small and/or wireless electronic devices in a smart structure and system.In this paper,a novel broadband vibration energy harvester is designed and analyzed,which consists of three cantilever beams,two magnetoelectric(ME) transducers and a magnetic circuit.A theoretical model is developed to analyze the effects of the structure parameters on the frequency response and the electrical output for achievin...     

MEMS压电阵列振动能量收集器

近年来,随着微能源的发展,微型压电振动能量收集器得到了广泛关注,但传统d31模式PZT薄膜微型压电振动能量收集器输出电压普遍较低,难以满足应用需求。为提高微型压电振动能量收集器的输出电压,论文提出了共质量块悬臂梁阵列压电振动能量收集器新结构,该结构包含压电悬臂梁单元组成的阵列和一个质量块,悬臂梁阵列共用质量块。采用有限元方法对该结构进行了优化设计,得到压电悬臂梁单元优化尺寸为3 mm×2.4 mm×0.05 mm,硅质量块优化尺寸为8 mm×12.4mm×0.5 mm。设计了MEMS压电阵列振动能量收集器加工工艺流程,加工出原理样件。在1 gn加速度,239.7 Hz谐振频率激励下,测试得到样件输出开路电压有效值为9.16 V;在最优化负载200 kΩ下,负载输出电压有效值为5.51 V,输出功率为151.8μW。     

一种新型压电俘能器的振动特性分析及性能研究

基于压电效应设计了一种包含屈曲梁、质量块和非线性弹簧的新型压电俘能器结构,并对其进行了振动响应分析.首先基于Euler-Bernoulli梁理论,利用Hamilton原理建立了压电俘能器结构的非线性动力学方程,通过Galerkin离散后数值分析了结构参数对系统一阶固有频率的影响;进一步利用多尺度法对系统进行摄动分析,研究了系统的稳态幅频特性,数值分析了各系数对幅频响应曲线的影响,结果表明该结构在简谐激励作用下会存在多种跳跃现象;最后数值分析了压电俘能器的发电性能,讨论了激励幅值和初始静挠度对发电电压的影响.     

非线性压电振动能量采集器的振动特性与实验研究

为了提高线性压电振动能量采集器的输出特性,在线性压电振动能量采集器悬臂梁末端引入Duffing非线性磁力,构造了一种双稳态非线性压电振动能量采集器;综合考虑能量采集器的动态振型与轴向应变分布情况,建立了系统非线性机电耦合集总参数运动控制模型,并利用4阶、5阶Runge-Kutta算法对能量采集器的非线性振动特性进行了数值模拟;利用谐波平衡法计算获得了能量采集器的幅频响应方程,数值分析了激励频率、激励幅值以及磁铁间距等对系统非线性振动特性的影响,发现双稳态运动可以极大地提高能量采集器的频率响应范围和能量采集效率,并且能量采集器在低频、低幅值激励情况下可以产生大幅值周期运动;最后,通过实验对数值计算结果进行了验证.     

Piezoelectric vibration energy harvester with tapered substrate thickness for uniform stress

Microsystem Technologies - This paper presents modification in the thickness profile of bimorph cantilever type piezoelectric vibration energy harvester (PVEH) to achieve uniform stress along the...     

Energy storage options for wireless sensors powered by aircraft specific thermoelectric energy harvester

This paper describes an approach for efficiently storing the harvested energy from a thermoelectric module for powering autonomous wireless sensor nodes in aircraft health monitoring applications. Thermoelectric devices are the preferred option due to the widespread availability of significant levels of energy from the temperature gradients or variations at the aircraft, such as the cabin, the engine compartment, the fuel tanks or the inner and outer frame of the fuselage. Batteries and supercapacitors are popular choices of storage device, but neither represents the ideal solution, with, supercapacitors possessing low energy densities while batteries have low power density. When using a battery-only solution for storage, the runtime of a typical sensor node is typically reduced by the battery’s relatively high internal impedance and thermal loss. Supercapacitors can overcome some of these problems, but generally do not provide sufficient long-term energy to allow aircraft health monitoring applications to be operated over an extended period. A hybrid energy storage solution can provide both energy and power density to a wireless sensor node simultaneously. Techniques such as acoustic–ultrasonic, acoustic-emission, strain and crack wire sensors require storage approaches that can provide immediate energy on demand, usually in short, high intensity bursts, and that can be sustained over long periods of time, storing up to 40–50 J of energy. This application requirement is considered as a significant constraint when working with battery-only and supercapacitor-only solutions. The hybrid system described here provides an alternate viable solution.     

悬臂梁式压电双晶片振动能量采集器的模型与实验研究

针对悬臂梁式双压电晶片振动能量采集器的质量效应问题,通过幅值修正方法建立了能量采集器的集总参数修正模型,利用阻抗分析和导纳圆法对模型参数进行了识别,得到了采集器在简谐基础激励作用下的机电耦合输出传递函数表达式;建立了悬臂梁压电振动能量采集器的实验系统,实验与仿真分析了悬臂梁末端质量、负载电阻等对能量采集器输出特性的影响,结果表明理论仿真结果与实验结果具有很好的吻合度,证明本文模型有利于提高压电振动能量采集器输出性能的分析预测精度。     

Numerical and experimental analysis of piezoelectric vibration energy harvester in IoT based F-SEPS application using optimization techniques

Microsystem Technologies - This study presents the Internet-of-things (IoT) based Foot-step equipped piezoelectric sensors (F-SEPS) application, which are used for charging the mobile phone devices...     

带弹性放大器的双稳态压电振动能量采集器

针对带弹性放大器的双稳态压电振动能量采集器,利用Hamilton原理和Raleigh-Ritz方法建立了压电振动能量采集器的机电耦合分布参数模型.重点分析了激励频率Ω≥1时系统质量比、刚度比、磁铁对间距等参数对系统输出性能的影响.研制了压电振动能量采集器原理样机,搭建了实验测试平台,实验测试了压电振动能量采集器的输出性能.研究结果表明带弹性放大器的压电振动能量采集器是一个非线性双自由度系统,具有两个双稳态运动区域;在激励频率Ω≥1时压电振动能量采集器需要较大的激励能量才能进入大幅值周期振动状态.     

压电振动能量采集器的力电耦合模型及其功率优化*

为提高传统压电振动能量采集器集总参数模型的性能预测精度,考虑悬臂梁的振型信息与轴向应变分布情况,提出了一种改进的力电耦合模型,该模型引入无因次幅值修正因子,通过曲线拟合方法确定了修正因子与振型函数和振动幅值之间的关系表达式;利用Rayleigh-Ritz模态分析法确定了力电耦合模型中的集总等效参数(如质量、刚度等),并根据弹性动力学原理建立了能量采集器的运动控制方程,得到了稳态时能量采集器的力、电输出响应表达式;最后,利用改进的模型对能量采集器的负载电阻和输出功率进行了优化,得到了负载短路和负载开路时能量采集器的最优输出特性。仿真结果与实例对比验证了提出模型的正确性,表明改进的力电耦合模型具有较高的预测精度。     

基于振动能量采集器的无源无线传感节点技术研究

随着以MEMS技术为依托,结合压电效应的振动能量采集技术的日臻完善,如何利用振动能量采集器构成高效的无源无线传感节点成为近期研究热点,而能量采集器输出的电能储存控制和低功耗发射技术是实现该节点的难点。在设计出对储能电容电压具有双阈值检测与控制功能的低功耗电路基础上,给出了一种自报警、无源无线低功耗传感节点。实验表明,在频率52 Hz正弦振动、振动加速度幅值为5 gn激励下,经过125 s的能量储存,节点能够以+10 dBm功率在16 ms内完成发射及无线报警,发射距离可达1.31 km。该节点构成的无线传感网络可广泛应用于石油管线、桥梁和军事侦察等外部供电极度受限环境的现场监控等用途。     

Wideband auto-tunable vibration energy harvester using change in centre of gravity

Microsystem Technologies - Energy harvesters are preferred for enhancing the life of IoT nodes. In this paper, a vibration energy harvester with wideband auto-tunable resonant frequency for...     

Enhancement of vibration based piezoelectric energy harvester using hybrid optimization techniques

Microsystem Technologies - MEMS unimorph piezoelectric vibration energy harvester is designed and optimized based on Hybrid Optimization techniques [genetic algorithm (GA), bat algorithm (BA), grey...     

某飞机安全销试验夹具的仿真设计

为获得满足某飞机安全销应急断离试验要求及相关设计规范的试验夹具,采用MSC Nastran分别对3种设计方案进行强度和刚度仿真分析.考虑材料非线性和多体接触的影响,得到结构类型、尺寸和材料不同的夹具的力学响应,通过对危险部位的强度校核筛选得到符合要求的试验夹具.试验结果表明数值仿真结果准确、可靠,可为同类试验夹具的设计提供参考.