Material Property Manipulation of Photopolymer Vibration Energy Harvesters

2012 ◽  
Author(s):  
Evan Baker ◽  
Timothy Reissman ◽  
Fan Zhou ◽  
Cheng Sun
Keyword(s):  
Flexural Rigidity ◽  
Three Dimensional ◽  
Effective Elastic Modulus ◽  
Electrical Energy ◽  
Vibration Energy ◽  
Energy Harvesters ◽  
Post Process ◽  
Naturally Occurring ◽  
Output Increase ◽  
Projection Microstereolithography

The inefficiency in converting naturally occurring vibration frequencies (sub-100 Hz) to electrical energy continues to be a major obstacle for miniaturized vibration energy harvesters. In a recent work, we addressed this issue by introducing photopolymer-based designs, using projection microstereolithography which exhibited 61 Hz resonant frequencies due to low elastic moduli and low flexural rigidity using a three-dimensional, helical coil design. In this paper, we extend upon those findings to report on a post-process technique which uses ultraviolet exposure time to manipulate the material properties of photopolymer-based vibration energy harvesters. The results show with 1–3 minutes of post-exposure, an effective elastic modulus variation from 399–904 MPa and a parasitic damping change from 0.0595–0.0986 kgs−1. Likewise, resonant frequency shifts of 53.5–805 Hz and power output increase from 56.5 to 120.4 μW (when excited at a constant acceleration of 6.06±0.06 ms−2) are achieved, without geometry changes and using the same photopolymer material.

Investigation of Vibration Energy Harvesting Using Two Cantilevers With Random Input

2017 ◽  
Author(s):  
Wei Yang ◽  
Panagiotis Alevras ◽  
Shahrzad Towfighian
Keyword(s):  
Mechanical Energy ◽  
Duffing Oscillator ◽  
Electrical Energy ◽  
Potential Energy Function ◽  
Excitation Level ◽  
Vibration Energy ◽  
Random Input ◽  
Vibration Energy Harvesting ◽  
Energy Harvesters ◽  
Low Performance

There is a growing interest to convert ambient mechanical energy to electrical energy by vibration energy harvesters. Realistic vibrations are random and spread over a large frequency range. Most energy harvesters are linear with narrow frequency bandwidth and show low performance, which led to creation of nonlinear harvesters that have larger bandwidth. This article presents a simulation study of a nonlinear energy harvester that contains two cantilever beams coupled by magnetic force. One of the cantilever beam is covered partially by piezoelectric material, while the other beam is normal to the first one and is used to create a variable potential energy function. The variable double-well potential function enables optimum conversion of the kinetic energy and thus larger output. The system is modeled by coupled Duffing oscillator equations. To represent the ambient vibrations, the response to Gaussian random input signal (generated by Shinozuka formula) is studied using power spectral density. The effects of different parameters on the system are also investigated. The results show that the double cantilever harvester has a threshold distance, where the harvester can perform optimally regardless of the excitation level. This observation is opposite to that of the conventional fixed magnet cantilever system where the optimal distance varies with the excitation level. Results of this study can be used to enhance energy efficiency of vibration energy harvesters.

scholarly journals Microstereolithography of Three-Dimensional Polymeric Springs for Vibration Energy Harvesting

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Evan Baker ◽  
Timothy Reissman ◽  
Fan Zhou ◽  
Chen Wang ◽  
Kevin Lynch ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Three Dimensional ◽  
Low Frequency ◽  
Electrical Energy ◽  
Maximum Energy ◽  
Open Circuit ◽  
Vibration Energy ◽  
Vibration Energy Harvesting ◽  
Spring Element ◽  
Constant Pitch

The inefficiency in converting low frequency vibration (6~240 Hz) to electrical energy remains a key issue for miniaturized vibration energy harvesting devices. To address this subject, this paper reports on the novel, three-dimensional micro-fabrication of spring elements within such devices, in order to achieve resonances and maximum energy conversion within these common frequencies. The process, known as projection microstereolithography, is exploited to fabricate polymer-based springs direct from computer-aided designs using digital masks and ultraviolet-curable resins. Using this process, a micro-spring structure is fabricated consisting of a two-by-two array of three-dimensional, constant-pitch helical coils made from 1,6-hexanediol diacrylate. Integrating the spring structure into an electromagnetic device, with a magnetic load mass of 1.236 grams, the resonance is measured at 61 Hz, which is within 2% of the theoretical model. The device provides a maximum normalized power output of 9.14 μW/G (G=9.81 ms−2) and an open circuit normalized voltage output of 621 mV/G. To the best of the authors knowledge, notable features of this work include the lowest Young’s modulus (530 MPa), density (1.011 g/cm3), and “largest feature size” (3.4 mm) for a spring element in a vibration energy harvesting device with sub-100 Hz resonance.

A Piezoelectric Based Energy Harvester with Magnetic Interactions: Modelling and Simulation

2015 ◽  
Vol 1115 ◽  
pp. 549-554
Author(s):  
Dauda Sh. Ibrahima ◽  
Asan G.A. Muthalif ◽  
Tanveer Saleh
Keyword(s):  
Kinetic Energy ◽  
Permanent Magnets ◽  
Energy Harvester ◽  
Electrical Energy ◽  
Lumped Parameter Model ◽  
Magnetic Interactions ◽  
Vibration Energy ◽  
Mems Devices ◽  
Energy Harvesters ◽  
Tip Mass

In recent years, utilizing kinetic energy in mechanical vibrations has become an interesting area of research. This is due to ubiquitous sources of vibration energy, coupled with the ever increasing demands to power wireless sensing electronics and Microelectromechanical (MEMs) devices with low energy requirements. Thus, researchers have ventured into developing different system configurations with the aim of harvesting vibration energy to power these devices. Cantilever beam systems with piezoelectric layer have been used as vibration energy scavengers due to their abilities of converting kinetic energy in vibrating bodies into electrical energy, whereas permanent magnets have been used to improve their performance. The only unresolved challenge is to develop energy harvesters that can produce optimum energy at a wider bandwidth. In this study, a mathematical model of a system of cantilever beams with piezoelectric layers having a magnetic coupled tip mass is proposed. The lumped parameter model of the harvester is developed to estimate the power output of the proposed harvester, and to visualise the effect of magnetic coupled tip mass in widening the frequency bandwidth of the energy harvester. Preliminary Simulation results using MATLAB have however shown the effectiveness of the proposed system.

Stationary Response of Nonlinear Vibration Energy Harvesters by Path Integration

2021 ◽  
Author(s):  
H. T. Zhu ◽  
Y.G. Xu ◽  
Yang Yu ◽  
Lixin Xu
Keyword(s):  
Nonlinear Vibration ◽  
Path Integration ◽  
Integration Method ◽  
Three Dimensional ◽  
Vibration Energy ◽  
Integration Scheme ◽  
Equivalent Linearization ◽  
Moment Equations ◽  
Energy Harvesters ◽  
Path Integration Method

Abstract A path integration procedure based on Gauss-Legendre integration scheme is developed to analyze probabilistic solution of nonlinear vibration energy harvesters (VEH) in this paper. First, traditional energy harvesters are briefly introduced and their non-dimensional governing and moment equations are given. These moment equations could be solved through the Runge-Kutta and Gaussian closure method. Then, the path integration method is expanded to three-dimensional situation, solving the probability density function (PDF) of VEH. Three illustrative examples are considered to evaluate the effectiveness of this method. The effectiveness of nonlinearity of traditional monostable VEH and a bistable VEH are further studied too. At the same time, Equivalent linearization method(EQL) and Monte Carlo simulation are employed too. The results indicate that three-dimensional path integration method can give satisfactory results for the global PDF, especially for the tail PDF, and they have better agreement with the simulation results than those of the EQL. In addition, the different degrees of hardening and softening behaviors of the PDFs occur when the nonlinearity coefficient increases and the bistable type is considered.

Enhancing Energy Harvesting Performance of PDMS based Piezocomposites via Synergistic Effect

2021 ◽  
Author(s):  
Yijin Hao ◽  
Yudong Hou ◽  
Hui Xu ◽  
Xin Gao ◽  
Mupeng Zheng ◽  
...  
Keyword(s):  
Synergistic Effect ◽  
Electronic Devices ◽  
Electrical Energy ◽  
The Self ◽  
Energy Requirements ◽  
Vibration Energy ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Wearable Electronic ◽  
Wearable Electronic Devices

Due to the self-supplied energy requirements of wearable electronic devices, flexible piezoelectric energy harvesters (FPEHs) that can convert waste vibration energy in the environment into electrical energy have received widespread...

Resin-bonded NdFeB micromagnets for integration into electromagnetic vibration energy harvesters

2013 ◽  
Vol 14 (4) ◽  
pp. 283-287 ◽  
Author(s):  
Pei-hong Wang ◽  
Kai Tao ◽  
Zhuo-qing Yang ◽  
Gui-fu Ding
Keyword(s):  
Vibration Energy ◽  
Energy Harvesters ◽  
Electromagnetic Vibration

scholarly journals Shock reliability enhancement for MEMS vibration energy harvesters with nonlinear air damping as a soft stopper

2017 ◽  
Vol 27 (10) ◽  
pp. 104003 ◽  
Author(s):  
Shao-Tuan Chen ◽  
Sijun Du ◽  
Emmanuelle Arroyo ◽  
Yu Jia ◽  
Ashwin Seshia
Keyword(s):  
Vibration Energy ◽  
Energy Harvesters ◽  
Air Damping ◽  
Reliability Enhancement

Minimization of the Local Residual Stress in 3D Flip Chip Structures by Optimizing the Mechanical Properties of Electroplated Materials and the Alignment Structure of TSVs and Fine Bumps

2011 ◽  
Author(s):  
Kohta Nakahira ◽  
Hironori Tago ◽  
Fumiaki Endo ◽  
Ken Suzuki ◽  
Hideo Miura
Keyword(s):  
Mechanical Properties ◽  
Residual Stress ◽  
Thermal Deformation ◽  
Flip Chip ◽  
Flexural Rigidity ◽  
Three Dimensional ◽  
Strain Gauges ◽  
Copper Interconnection ◽  
Induced Stress ◽  
Alignment Structure

Since the thickness of the stacked silicon chips in 3D integration has been thinned to less than 100 μm, the local thermal deformation of the chips has increased drastically because of the decrease of the flexural rigidity of the thinned chips. The clear periodic thermal deformation and thus, the thermal residual stress distribution appears in the stacked chips due to the periodic alignment of metallic bumps, and they deteriorate the reliability of products. In this paper, the dominant structural factors of the local residual stress in a silicon chip are discussed quantitatively based on the results of a three-dimensional finite element analysis and the measurement of the local residual stress in a chip using stress sensor chips. The piezoresistive strain gauges were embedded in the sensor chips. The length of each gauge was 2 μm, and an unit cell consisted of 4 gauges with different crystallographic directions. This alignment of strain gauges enables to measure the tensor component of three-dimensional stress fields separately. Test flip chip substrates were made by silicon chip on which the area-arrayed tin/copper bumps were electroplated. The width of a bump was fixed at 200 μm, and the bump pitch was varied from 400 μm to 1000 μm. The thickness of the copper layer was about 40 μm and that of tin layer was about 10 μm. This tin layer was used for the rigid joint formation by alloying with copper interconnection formed on a stress sensing chip. The measured amplitude of the residual stress increased from about 30 MPa to 250 MPa depending on the combination of materials such as bump, underfill, and interconnections. It was confirmed that both the material constant of underfill and the alignment structure of fine bumps are the dominant factors of the local deformation and stress of a silicon chip mounted on area-arrayed metallic bumps. It was also confirmed experimentally that both the hound’s-tooth alignment between a TSV (Through Silicon Via) and a bump and control of mechanical properties of electroplated copper thin films used for the TSV and bump is indispensable in order to minimize the packaging-induced stress in the three-dimensionally mounted chips. This test chip is very effective for evaluating the packaging-process induced stress in 3D stacked chips quantitatively.

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