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Low Resonant Frequency Energy Scavenging Based on Bi-Stability Structure Dynamics

基于双稳态结构动力学的低共振频率能量清除

基本信息

批准号：
1408005
负责人：
Thomas Berfield
金额：
$ 33.28万
依托单位：
University of Louisville Research Foundation Inc
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2014
资助国家：
美国
起止时间：
2014-08-15 至 2018-07-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1408005&HistoricalAwards=false
关键词：
Low Resonant Frequency Energy Scavenging

项目摘要

Scavenging energy from structure vibrations is one highly promising method for potentially replacing power sources used in many applications that have traditionally used batteries. Many structures serve as natural vibration sources, such as bridges swaying due to wind loads or pipelines vibrating due to the oil flow within, which offer unique opportunities to generate energy. The primary challenge for effective implementation is developing harvesting devices that work optimally under the low frequency and somewhat random vibration conditions typical of most ambient environments. This project will explore the nonlinear response of buckled beam structures as a means to enhance power output under these chaotic, low frequency conditions. Bi-stable systems, such as buckled beams, naturally have two stable states and a nonlinear dynamic response, which has been previously shown to be ideal for irregular loading scenarios. This work seeks to improve energy harvesting efficiency under these conditions by investigating the behavior dictating switching between the stable buckled states for the unique proposed energy harvester design. Microscale versions of this device targeted for wireless sensor power applications will be probed through experiments and finite element analysis simulations. The research performed will help introduce a new class of energy harvesting devices, and will be supplemented with collaborations within the local community via the public library summer reading program and a local high school research experience outreach program. The research outcomes achieved through this work and core insights will be widely disseminated through the traditional means of publications, conferences, and workshops. Educational outreach plans will serve underrepresented groups K-12 students and the general public through a community engagement partnership the PI has created with the Louisville Free Public Library. This arrangement will help teach key engineering concepts and promote direct interaction between the PI and the larger community via several science-based activities arranged in conjunction with the library's summer reading program. In addition, the PI has solidified a relationship with a local high school science department chair to engage students on engineering topics, and recruit a diverse student group for summer research experiences working in the energy harvesting area.The objective of this research is to improve the real-world power scavenging capabilities of MEMS-scale energy harvesters through a system optimally designed for ambient vibration levels (40 Hz) with chaotic impulse characteristics. This challenge is approached through an investigation of the system dynamics of an energy harvesting design featuring buckled beam stability state switching. Finite element modeling of structure deformations and the associated power production will be performed, with experimental testing of devices used for validation of optimized performance parameters. The focus of this project is on the nonlinear dynamic response of bi-stable buckled structures, which is leveraged to optimize strain/power generation within integrated piezoelectric over a broad spectrum of excitation frequencies. The proposed class of buckled structure MEMS work in a fundamentally different way than other bi-stable MEMS energy harvesters, creating large deformations by manipulating the constraint conditions of the structure to induce switching. The approach of using switching between buckling stability states allows for a system response that naturally is adaptive to the vibration intensity. The design used herein is unique amongst other bi-stable buckled structures, in that very low resonant frequency ranges can be targeted. Multi-node design iterations based on the same operating principle offers a potential new class of MEMS energy harvesting devices, while electro-mechanical relationships developed to describe the power generation from buckled beam stability switching will be of interest to the broader energy harvesting field. Of particular interest to the energy harvesting community will be the development of power generation models describing strains during stability state switching.

从结构振动中收集能量是一种非常有前途的方法，可以替代传统上使用电池的许多应用中使用的电源。许多结构都是自然振动源，例如桥梁因风荷载而摇摆或管道因内部油流而振动，这为产生能量提供了独特的机会。有效实施的主要挑战是开发在大多数周围环境典型的低频和有点随机的振动条件下最佳工作的收获设备。本计画将探讨屈曲梁结构的非线性反应，作为在这些混乱、低频条件下提高功率输出的一种手段。双稳态系统，如屈曲梁，自然有两个稳定状态和非线性动态响应，这已被证明是理想的不规则的负载情况。这项工作旨在提高能量收集效率，在这些条件下，通过调查的行为指示之间的切换稳定的屈曲状态的独特的能量收集器设计。针对无线传感器电源应用的该设备的微型版本将通过实验和有限元分析模拟进行探讨。进行的研究将有助于引入一种新的能量收集设备，并将通过公共图书馆暑期阅读计划和当地高中研究经验推广计划与当地社区合作进行补充。通过这项工作取得的研究成果和核心见解将通过出版物、会议和讲习班等传统手段广泛传播。教育推广计划将通过PI与路易斯维尔免费公共图书馆建立的社区参与伙伴关系，为代表性不足的K-12学生和公众服务。这种安排将有助于教授关键的工程概念，并通过与图书馆的夏季阅读计划一起安排的几项以科学为基础的活动，促进PI与更大社区之间的直接互动。此外，PI已经巩固了与当地高中科学系主任的关系，让学生参与工程主题，并招募一个多样化的学生小组，在能量收集领域进行夏季研究经验。本研究的目标是通过针对环境振动水平（40 Hz）进行优化设计的系统，提高MEMS规模能量收集器的实际功率收集能力。具有混沌脉冲特性。这一挑战是接近通过调查的能量收集设计具有屈曲梁稳定状态切换的系统动力学。将进行结构变形和相关发电的有限元建模，并对用于验证优化性能参数的设备进行实验测试。该项目的重点是双稳态屈曲结构的非线性动态响应，这是利用优化应变/发电内集成压电在一个广泛的激励频率范围。所提出的一类屈曲结构MEMS以与其他双稳态MEMS能量采集器根本不同的方式工作，通过操纵结构的约束条件来引起切换，从而产生大的变形。使用屈曲稳定性状态之间的切换的方法允许自然地适应振动强度的系统响应。这里使用的设计在其他双稳态屈曲结构中是独特的，因为可以针对非常低的谐振频率范围。基于相同工作原理的多节点设计迭代提供了一种潜在的新型MEMS能量收集设备，而开发用于描述屈曲梁稳定性切换发电的机电关系将对更广泛的能量收集领域产生兴趣。特别感兴趣的能量收集社区将是发电模型的发展，描述在稳定状态切换过程中的应变。