Analysis of Magnetic Forces in Two-Dimensional Space With Applications for the Tuning of Vibration Energy Harvesting Devices

2015 ◽  
Author(s):  
Lin Dong ◽  
Frank T. Fisher
Keyword(s):  
Energy Harvesting ◽  
Frequency Tuning ◽  
Dimensional Space ◽  
Electrical Energy ◽  
Ambient Vibration ◽  
Two Dimensional ◽  
Vibration Energy Harvesting ◽  
Resonant Frequencies ◽  
Magnetic Forces ◽  
Energy Harvesting Devices

Vibration-based energy harvesting is a process by which ambient vibrations are converted to electrical energy, and is of interest for supplementing or replacing the batteries of individual nodes comprising wireless sensor networks among other applications. Generally, it is desired to match the resonant frequencies of the device with the primary ambient vibration frequencies for optimal energy harvesting performance. While previous work has demonstrated the use of magnetic forces to tune the resonant frequencies of vibrating energy harvesting structures, such efforts have been limited to one-dimensional analyzes. Here frequency tuning is realized by applying magnetic forces to the device in two-dimensional space, such that the resulting magnetic force has both horizontal and vertical components. In the case of a cantilever beam, the transverse force contributes to the transverse stiffness of the system while the axial force contributes to a change in the geometric stiffness of the beam. The effective resonant frequency of the device is then a function of the contributions of the original stiffness of the beam and the two additional stiffness components introduced by the presence of the magnet in 2D space. The simulation results from a COMSOL magnetostatics 3D model agree well with an analytical model describing the magnetic forces between the magnets as a function of location. Such 2D magnetic stiffness tuning approaches may be useful in applications where space constraints impact the available design space of the energy harvester.

Topology Optimization of Piezoelectric Energy Harvesting Devices Subjected to Stochastic Excitation

2010 ◽  
Author(s):  
Zheqi Lin ◽  
Hae Chang Gea ◽  
Shutian Liu
Keyword(s):  
Topology Optimization ◽  
Energy Harvesting ◽  
Electrical Energy ◽  
Ambient Vibration ◽  
Piezoelectric Energy Harvesting ◽  
The Past ◽  
Piezoelectric Energy ◽  
Random Responses ◽  
Pseudo Excitation ◽  
Energy Harvesting Devices

Converting ambient vibration energy into electrical energy using piezoelectric energy harvester has attracted much interest in the past decades. In this paper, topology optimization is applied to design the optimal layout of the piezoelectric energy harvesting devices. The objective function is defined as to maximize the energy harvesting performance over a range of ambient vibration frequencies. Pseudo excitation method (PEM) is applied to analyze structural stationary random responses. Sensitivity analysis is derived by the adjoint method. Numerical examples are presented to demonstrate the validity of the proposed approach.

Improved Adjusting Capacitor Method for Piezoelectric Frequency Tuning and Maximum Energy Harvesting

2014 ◽  
Author(s):  
Murtadha A. AL Maliki ◽  
Karla M. Mossi
Keyword(s):  
Energy Harvesting ◽  
Resonance Frequency ◽  
Frequency Tuning ◽  
Electrical Energy ◽  
Load Resistance ◽  
Maximum Power ◽  
Ambient Vibration ◽  
Passive Element ◽  
Power Extraction ◽  
Shunt Capacitor

Energy harvesting refers to conversion of ambient energy into electrical energy. A typical way to accomplish this conversion is through the use of a piezoelectric harvester. This device produces a maximum power when its natural resonance frequency matches that of the ambient vibration. This property is the main limitation to developing many application. To address this restriction, it has been proposed by several investigators that a capacitor be connected in parallel to a piezoelectric cantilever as a method of electrical tuning. When such passive element is connected, the power decreases from its original value. In this paper an improvement to this approach is proposed. Once the tuning capacitor is connected, an inductor value is chosen such that conjugate impedance matching becomes reasonable and plugging this component can give an improvement for both the voltage and power generated. Capacitors of 0.2 μF to 1.5μF values were connected in parallel to a piezoelectric unimorph Type TH-7R with an inherent capacitance of 166 nF and a 208 Hz resonance frequency to develop a tuning range of four Hz. The harvested power during the tuning was proved to be correlated inversely to the shunt capacitor value. By connecting a 700 mH and 2 H inductors in parallel to the system, a significant improvement in power was obtained. In addition, a correlation between the resonance frequency and optimal load resistance with the shunt capacitor value has been studied. The results show that this innovative method is an efficient method for frequency tuning and maximum power extraction.

Comparing Linear and Essentially Nonlinear Vibration-Based Energy Harvesting

2008 ◽  
Author(s):  
D. Dane Quinn ◽  
Angela L. Triplett ◽  
Lawrence A. Bergman ◽  
Alexander F. Vakakis
Keyword(s):  
Energy Harvesting ◽  
Environmental Conditions ◽  
Mechanical Energy ◽  
Electrical Energy ◽  
Ambient Vibration ◽  
Ambient Conditions ◽  
Harvesting Systems ◽  
Linear Elements ◽  
And Performance ◽  
Energy Harvesting Devices

Self-contained long-lasting energy sources are rapidly increasing in importance as portable electronics and inaccessible devices such as wireless sensors are finding wider and more varied applications. However, in many circumstances replacing power supplies, such as conventional batteries, becomes impractical and the development of a self-renewing source of energy is paramount to the continued development of such devices. The ability to convert ambient mechanical energy to usable electrical energy fills these requirements and one aspect of current research seeks to increase the efficiency and performance of these energy harvesting systems. However, to achieve acceptable performance conventional vibration-based energy harvesting devices based on linear elements must be specifically tuned to match environmental conditions such as the frequency and amplitude of the external vibration. As the environmental conditions vary under ambient conditions the performance of these linear devices is dramatically decreased. The strategy to efficiently harvest energy from low-level, intermittent ambient vibration, proposed herein, relies on the unique properties of a particular class of strongly nonlinear vibrating systems that are referred to as “essentially” nonlinear.

A Wide Frequency Range Tunable Vibration Energy Harvesting Device Using Magnetically Induced Stiffness

2007 ◽  
Author(s):  
Vinod R. Challa ◽  
M. G. Prasad ◽  
Yong Shi ◽  
Frank Fisher
Keyword(s):  
Energy Harvesting ◽  
Resonance Frequency ◽  
Vibration Energy ◽  
Frequency Range ◽  
Vibration Energy Harvesting ◽  
Magnetic Forces ◽  
Resonance Frequencies ◽  
Wide Range ◽  
Continuous Power ◽  
Energy Harvesting Devices

Although wireless sensors show extensive promise across a wide range of applications, one requirement necessary for widespread deployment is a suitable long-life power source. Self sustainable powering techniques allow for efficient use of these sensors, whose potential life is usually longer than that of the power sources. Vibration energy harvesting techniques offer to have the potential to be employed in powering these devices. The most important requirement of vibration energy harvesting devices is that they be in resonance to harvest energy efficiently. Most of the vibration energy harvesting devices built, irrespective of the mechanism involved, are based on a single resonance frequency, with the efficiency of these devices is very much limited to that specific frequency. In this paper, a frequency tunable mechanism is presented which allows the energy harvesting device to generate power over a wide range of frequencies. External magnetic forces have been used to induce additional stiffness which is variable depending on the distance between the magnets. This technique allowed us to tune the resonance frequencies to have +/− 20% of the original (untuned) resonant frequency. Further, the device can be tuned to higher and lower frequency with respect to the untuned resonance frequency by using attractive and repulsive magnetic forces, respectively. As a proof-of-concept, a piezoelectric cantilever-based energy harvesting device with a natural frequency of 26 Hz was fabricated whose resonance frequency was successfully tuned over a frequency range of 22 Hz to 32 Hz, enabling a continuous power output of 240 μW to 280 μW over the entire frequency range. The tuning mechanism can be employed to any vibrating structure.

Fractal-Inspired Multi-Frequency Structures for Piezoelectric Harvesting of Ambient Kinetic Energy

2010 ◽  
Author(s):  
D. Castagnetti
Keyword(s):  
Energy Harvesting ◽  
Electrical Energy ◽  
Ambient Vibration ◽  
Piezoelectric Energy Harvesting ◽  
Piezoelectric Energy ◽  
Bending Strain ◽  
Macro Scale ◽  
Suitable Form ◽  
Conversion Technologies ◽  
Energy Harvesting Devices

The investigation of energy harvesting devices, able to convert freely-available ambient energy into electrical energy, has significantly improved. To this aim, the most suitable form of ambient energy is the kinetic one, being almost ubiquitous and easily accessible. Among the available conversion technologies, piezoelectric energy harvesting devices are one of the most promising, due to their simple configuration and high conversion efficiency. The most demanding task is to identify simple and efficient multi-frequency structures in the ambient vibration range. To this aim, this work proposes four fractal-inspired structures for piezoelectric energy harvesting. Through computational analysis, their frequency response is calculated up to 100Hz. The structures are examined both in the micro and macro scale and the effect of the iteration level of the fractal geometry is also assessed. By considering the bending strain associated to each mode shape, a quantitative criterion to assess the harvesting efficiency of the proposed structures is introduced.

scholarly journals Piezoelectric property comparison of two-dimensional ZnO nanostructures for energy harvesting devices

RSC Advances ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 3363-3370
Author(s):  
Ang Yang ◽  
Yu Qiu ◽  
Dechao Yang ◽  
Kehong Lin ◽  
Shiying Guo
Keyword(s):  
Energy Harvesting ◽  
Piezoelectric Property ◽  
Piezoelectric Effect ◽  
Theoretical Studies ◽  
Two Dimensional ◽  
Zno Nanostructures ◽  
Energy Harvesting Devices ◽  
Experimental And Theoretical Studies

In this paper, experimental and theoretical studies of the piezoelectric effect of two-dimensional ZnO nanostructures, including straight nanosheets (SNSs) and curved nanosheets (CNSs) are conducted.

scholarly journals A Study on the Energy-Harvesting Device with a Magnetic Spring for Improved Durability in High-Speed Trains

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 830
Author(s):  
Jaehoon Kim
Keyword(s):  
Energy Harvesting ◽  
High Speed ◽  
Permanent Magnets ◽  
Critical Issue ◽  
Sensor Nodes ◽  
High Speed Train ◽  
Vibration Energy Harvesting ◽  
Magnetic Spring ◽  
High Speed Trains ◽  
Energy Harvesting Devices

Durability is a critical issue concerning energy-harvesting devices. Despite the energy-harvesting device’s excellent performance, moving components, such as the metal spring, can be damaged during operation. To solve the durability problem of the metal spring in a vibration-energy-harvesting (VEH) device, this study applied a non-contact magnetic spring to a VEH device using the repulsive force of permanent magnets. A laboratory experiment was conducted to determine the potential energy-harvesting power using the magnetic spring VEH device. In addition, the characteristics of the generated power were studied using the magnetic spring VEH device in a high-speed train traveling at 300 km/h. Through the high-speed train experiment, the power generated by both the metal spring VEH device and magnetic spring VEH device was measured, and the performance characteristics required for a power source for wireless sensor nodes in high-speed trains are discussed.

A Creative Vibration Energy Harvesting System to Support a Self-Powered Internet of Thing (IoT) Network in Smart Bridge Monitoring

2020 ◽  
Author(s):  
Saman Farhangdoust ◽  
Claudia Mederos ◽  
Behrouz Farkiani ◽  
Armin Mehrabi ◽  
Hossein Taheri ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Cantilever Beam ◽  
Average Power ◽  
Electrical Energy ◽  
Laser Vibrometer ◽  
Stay Cable ◽  
Fe Modelling ◽  
Vibration Energy Harvesting ◽  
Piezoelectric Energy ◽  
Energy Harvesting System

Abstract This paper presents a creative energy harvesting system using a bimorph piezoelectric cantilever-beam to power wireless sensors in an IoT network for the Sunshine Skyway Bridge. The bimorph piezoelectric energy harvester (BPEH) comprises a cantilever beam as a substrate sandwiched between two piezoelectric layers to remarkably harness ambient vibrations of an inclined stay cable and convert them into electrical energy when the cable is subjected to a harmonic acceleration. To investigate and design the bridge energy harvesting system, a field measurement was required for collecting cable vibration data. The results of a non-contact laser vibrometer is used to remotely measure the dynamic characteristics of the inclined cables. A finite element study is employed to simulate a 3-D model of the proposed BPEH by COMSOL Multiphasics. The FE modelling results showed that the average power generated by the BPEH excited by a harmonic acceleration of 1 m/s2 at 1 Hz is up to 614 μW which satisfies the minimum electric power required for the sensor node in the proposed IoT network. In this research a LoRaWAN architecture is also developed to utilize the BPEH as a sustainable and sufficient power resource for an IoT platform which uses wireless sensor networks installed on the bridge stay cables to collect and remotely transfer bridge health monitoring data over the bridge in a low-power manner.

scholarly journals Analysis of Double Elastic Steel Wind Driven Magneto-Electric Vibration Energy Harvesting System

Sensors ◽  
2021 ◽  
Vol 21 (21) ◽  
pp. 7364
Author(s):  
Yi-Ren Wang ◽  
Ming-Ching Chu
Keyword(s):  
Energy Harvesting ◽  
Electric Energy ◽  
Elastic Beam ◽  
Electrical Energy ◽  
Vibration Energy ◽  
Vibration Energy Harvesting ◽  
Concentrated Load ◽  
Single Beam ◽  
Piezoelectric Patch ◽  
Energy Harvesting System

This research proposes an energy harvesting system that collects the downward airflow from a helicopter or a multi-axis unmanned rotary-wing aircraft and uses this wind force to drive the magnet to rotate, generating repulsive force, which causes the double elastic steel system to slap each other and vibrate periodically in order to generate more electricity than the traditional energy harvesting system. The design concept of the vibration mechanism in this study is to allow the elastic steel carrying the magnet to slap another elastic steel carrying the piezoelectric patch to form a set of double elastic steel vibration energy harvesting (DES VEH) systems. The theoretical DES VEH mechanism of this research is composed of a pair of cantilever beams, with magnets attached to the free end of one beam, and PZT attached to the other beam. This study analyzes the single beam system first. The MOMS method is applied to analyze the frequency response of this nonlinear system theoretically, then combines the piezoelectric patch and the magneto-electric coupling device with this nonlinear elastic beam to analyze the benefits of the system’s converted electrical energy. In the theoretical study of the DES VEH system, the slapping force between the two elastic beams was considered as a concentrated load on each of the beams. Furthermore, both SES and DES VEH systems are studied and correlated. Finally, the experimental data and theoretical results are compared to verify the feasibility and correctness of the theory. It is proven that this DES VEH system can not only obtain the electric energy from the traditional SES VEH system but also obtain the extra electric energy of the steel vibration subjected to the slapping force, which generates optimal power to the greatest extent.

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