A Piezoelectric Regenerative Damper for Low-Frequency Application

2014 ◽  
Author(s):  
Arata Masuda ◽  
Yasuhiro Hiraki ◽  
Koki Yamane ◽  
Akira Sone
Keyword(s):  
Free Vibration ◽  
High Efficiency ◽  
Vibration Suppression ◽  
Mechanical Energy ◽  
Electric Energy ◽  
Low Frequency ◽  
Offshore Structures ◽  
Circuit Switching ◽  
Piezoelectric Cantilever ◽  
Input Motion

In this study, a design of a regenerative damper for low-frequency applications, such as vibration suppression of long period infrastructures, tanks and pipings, and maritime and offshore structures, is presented. In this design, the low-frequency input motion to the damper is transformed to a high-frequency motion of piezoelectric cantilever oscillators by mechanical switching, so that the input work into the damper during the loading phase induces the free vibration of the oscillator. The mechanical energy of the free vibration is converted to the electric energy by a high efficiency interfacing circuit. In this paper, a conceptual model is mathematically formulated and tested to evaluate the potential performance of the proposed idea. It is shown that the combination of the mechanical switching with a circuit switching interface technique can expect the enhancement of the energy regeneration efficiency up to 30%.

A Piezoelectric Energy Harvesting Damper for Low-Frequency Application

2015 ◽  
Author(s):  
Arata Masuda ◽  
Yasuhiro Hiraki ◽  
Naoto Ikeda ◽  
Akira Sone
Keyword(s):  
Energy Harvesting ◽  
High Efficiency ◽  
Electric Energy ◽  
Low Frequency ◽  
Offshore Structures ◽  
Piezoelectric Energy ◽  
Piezoelectric Cantilever ◽  
Work Input ◽  
Harvesting Efficiency ◽  
Energy Harvesting Efficiency

In this study, a design of an energy harvesting damper for low-frequency applications, such as energy harvesting from long period infrastructures, tanks and pipings, and maritime and offshore structures, is presented. In this design, the low-frequency relative motion of the damper is transformed into a high-frequency motion of a piezoelectric cantilever beam by a mechanical switching mechanism, referred to as “plucking” mechanism that couples and decouples the cantilever to the damper rod so that the input energy into the damper is converted to electric energy with high efficiency. In this paper, the energy harvesting efficiency is theoretically calculated for the harvesters with and without plucking mechanism and the optimized maximum performance is derived. Then the electrical switching circuit for the enhancement of the electromechanical conversion efficiency, referred to as “SSHI” interface is introduced. Numerical case studies suggest that the harvester with an ideally implemented parallel SSHI circuit can retrieve over 70 % energy of the maximum mechanical work input on the damper rod.

scholarly journals In-Ear Energy Harvesting: Harvester Design and Validation (Part II)

2021 ◽  
Vol 4 (1) ◽  
pp. 43
Author(s):  
Tigran Avetissian ◽  
Fabien Formosa ◽  
Adrien Badel ◽  
Michel Demuynck ◽  
Aidin Delnavaz ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Hearing Aids ◽  
Mechanical Energy ◽  
Morphological Variability ◽  
Electric Energy ◽  
Low Frequency ◽  
Joint Movement ◽  
Ear Canal ◽  
Human Ear ◽  
Promising Source

The mechanical deformation of the ear canal induced by the temporomandibular joint movement constitutes a promising source of energy to power in-ear devices (hearing aids, communication earpieces, etc.). The large morphological variability of the human ear canal and its intrinsic dynamic characteristics—with displacement frequencies below 1.5 Hz with an average volume variation of 60 mm3—motivate the development of non-conventional dedicated energy harvesting methods. This paper demonstrates the concept and design of a modular hydraulic–piezoelectric self-actuated frequency up-conversion micromachine for energy harvesting. The mechanical energy is conveyed using a liquid-filled custom fitted earplug, which can be considered as a hydraulic pump. A hydraulic circuit composed of a pressure amplifier, two driven valves and two check valves allows to drive two micro-pistons. These micro-pistons actuate a bistable oscillator associated to a piezoelectric transducer allowing the low frequency mechanical excitation to be efficiently converted into electric energy through frequency-up conversion. The two integrated passively driven valves are based on tube buckling and allow the pistons to act alternatively on the oscillator to generate a backward and forward run for two jaw movements. A complete theoretical multiphysics model of the machine has been established for the design and evaluation of the potential of the proposed approach. Global analytical and refined FEM approaches have been combined to integrate the fluid and mechanical behaviors. Based on simulation and preliminary experimental data, the harvested energy is expected to be 8 µJ for one jaw closing, with a theoretical 40% end-to-end conversion efficiency.

Dynamic Analysis of the Nonel Rotary Piezoelectric Generator

2012 ◽  
Vol 516-517 ◽  
pp. 1848-1853
Author(s):  
Bing Feng Han ◽  
Jin Kui Chu ◽  
Fei Yao ◽  
Ye Sheng Xiong ◽  
Xin Xin Huo
Keyword(s):  
Dynamic Analysis ◽  
Cantilever Beam ◽  
Magnetic Force ◽  
Driving Forces ◽  
Mechanical Energy ◽  
Dynamic Performance ◽  
Low Frequency ◽  
Transfer Energy ◽  
Piezoelectric Cantilever ◽  
Piezoelectric Generator

The method to transfer energy by less-contact magnetic force can decrease mechanical energy loss comparing with that by mechanical contact. In this paper, a novel piezoelectric rotary generator was designed based on the theory of the transition from less-contact magnetic force to the mechanical energy. ANSYS software was used to calculate the driving forces for the piezoelectric cantilever beam from the rotary wheel rotate in the different positions. The periodic driving force for the piezoelectric cantilever beam was obtained by the methods of fitting and Fourier transform. Laws of dynamic performance for piezoelectric cantilever beam were obtained by dynamic analysis. The results show that the low-frequency and variable rotational mechanical energy in the natural environment can be harvested by this novel rotary piezoelectric generator.

scholarly journals The Analysis and Design of a High Efficiency Piezoelectric Harvesting Floor with Impacting Force Mechanism

Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 380
Author(s):  
Sheng-He Wang ◽  
Mi-Ching Tsai ◽  
Tsung-His Wu
Keyword(s):  
Theoretical Model ◽  
Free Vibration ◽  
High Efficiency ◽  
Electric Energy ◽  
Voltage Source ◽  
Storage Capacitor ◽  
Analysis And Design ◽  
Wireless Transmitter ◽  
Potential Development ◽  
Compact Size

In renewable energy technology development, piezoelectric material has electro-mechanical converted capability and the advantages of simple construction and compact size, it has potential development since the environment vibration can be transferred into an electrical energy in daily harvesting applications. To improve the electro-mechanical converted efficiency of a piezoelectric harvester at low-frequency environment, a free vibration type of piezoelectric cantilever harvesting structure was proposed, which can generate a resonant oscillation by releasing an initial deformed displacement, and was uninfluenced from the effects of external environment. To analyze the harvesting behaviors, an equivalent circuit with voltage source was provided, and the parameters in theoretical model can be determined by the dimensions of the piezoelectric unimorph plate and its initial deformation. From the comparison of measurement and simulation, it reveals a significant efficient theoretical model where 8% error occurrence for storage energy was found. Finally, the proposed free-vibration generation method was developed in a piezoelectric harvesting floor design, which can transfer human walking motion into electric energy, and store in an external storage capacitor. From the testing result, one time of footstep motion can cause the charging energy in a 33 μF of storage capacitor achieve to 0.278 mJ, which was larger than the driven power of the wireless transmitter module, and then the wireless transmitter can be driven to send a RF signal without external power supply. Therefore, the designed piezoelectric harvesting floor has potential development to locate the user’s current position, which can provide users with future appropriate service for intelligent building application.

High-efficiency piezoelectric micro harvester for collecting low-frequency mechanical energy

2016 ◽  
Vol 27 (48) ◽  
pp. 485402 ◽  
Author(s):  
Xin Li ◽  
Jinhui Song ◽  
Shuanglong Feng ◽  
Xiong Xie ◽  
Zhenhu Li ◽  
...  
Keyword(s):  
High Efficiency ◽  
Mechanical Energy ◽  
Low Frequency

scholarly journals Hydrodynamic constraints on the energy efficiency of droplet electricity generators

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Antoine Riaud ◽  
Cui Wang ◽  
Jia Zhou ◽  
Wanghuai Xu ◽  
Zuankai Wang
Keyword(s):  
Energy Efficiency ◽  
Kinetic Energy ◽  
Total Energy ◽  
Viscous Dissipation ◽  
Shear Force ◽  
Mechanical Energy ◽  
Electric Energy ◽  
The Past ◽  
Viscous Shear ◽  
Impingement Velocity

AbstractElectric energy generation from falling droplets has seen a hundred-fold rise in efficiency over the past few years. However, even these newest devices can only extract a small portion of the droplet energy. In this paper, we theoretically investigate the contributions of hydrodynamic and electric losses in limiting the efficiency of droplet electricity generators (DEG). We restrict our analysis to cases where the droplet contacts the electrode at maximum spread, which was observed to maximize the DEG efficiency. Herein, the electro-mechanical energy conversion occurs during the recoil that immediately follows droplet impact. We then identify three limits on existing droplet electric generators: (i) the impingement velocity is limited in order to maintain the droplet integrity; (ii) much of droplet mechanical energy is squandered in overcoming viscous shear force with the substrate; (iii) insufficient electrical charge of the substrate. Of all these effects, we found that up to 83% of the total energy available was lost by viscous dissipation during spreading. Minimizing this loss by using cascaded DEG devices to reduce the droplet kinetic energy may increase future devices efficiency beyond 10%.

Construction of low-frequency and high-efficiency electromagnetic wave absorber enabled by texturing rod-like TiO2 on few-layer of WS2 nanosheets

2021 ◽  
Vol 548 ◽  
pp. 149158
Author(s):  
Deqing Zhang ◽  
Yingfei Xiong ◽  
Junye Cheng ◽  
Hassan Raza ◽  
Chuanxu Hou ◽  
...  
Keyword(s):  
Electromagnetic Wave ◽  
High Efficiency ◽  
Low Frequency ◽  
Ws2 Nanosheets

Realizing high-efficiency low frequency sound absorption of underwater meta-structures by acoustic siphon effect

2021 ◽  
pp. 2150319
Author(s):  
Li Bo Wang ◽  
Cheng Zhi Ma ◽  
Jiu Hui Wu ◽  
Chong Rui Liu
Keyword(s):  
Absorption Coefficient ◽  
Sound Absorption ◽  
High Efficiency ◽  
Physical Mechanism ◽  
Low Frequency ◽  
Area Ratio ◽  
Underwater Acoustic ◽  
Element Simulation ◽  
Average Absorption Coefficient ◽  
New Perspective

The underwater acoustic siphon effect is proposed in this work, which aims to reveal the basic physical mechanism of high-efficiency sound absorption in meta-structures composed of multiple detuned units. Furthermore, the influence of the area ratio on the underwater acoustic siphon effect is then investigated by finite element simulation (FES) and theoretical calculation. On this basis, a meta-structure with the maximum absorption coefficient of almost 100% and average absorption coefficient of 80% at 600–1400 Hz is achieved. The underwater acoustic siphon effect could provide a better understanding of high-efficiency sound absorption and offer a new perspective in controlling underwater noises.

Study of the effect of removing dental plaque using low-frequency ultrasound and ozonized contact medium on the clinical course of chronic generalized catarrhal gingivitis of young people

2021 ◽  
Vol 1 (12) ◽  
pp. 16-20
Author(s):  
G. R. Mhoyan ◽  
S. N. Razumova ◽  
A. G. Volkov ◽  
N. Z. Dikopova ◽  
A. S. Brago ◽  
...  
Keyword(s):  
Young People ◽  
Clinical Studies ◽  
Dental Plaque ◽  
Blood Circulation ◽  
High Efficiency ◽  
Clinical Course ◽  
Low Frequency ◽  
Low Frequency Ultrasound ◽  
Microcirculatory Disorders ◽  
Frequency Ultrasound

The dental status of 148 patients aged 18 to 22 years. All students who were diagnosed with generalized catarrhal gingivitis (46) were carried out removal of dental plaque with ozonation of the environment. The results of clinical studies indicate the high efficiency of the use of the removal of dental plaque using low-frequency ultrasound using an ozonized contact medium in the treatment of chronic generalized catarrhal gingivitis. The treatment carried out using this method contributed to the elimination of inflammation, the normalization of blood circulation in the gums. 3 months after the treatment, the achieved effect was preserved, which was confirmed by the data of clinical and functional research methods. Despite a slight increase in inflammation in the gums and a deterioration in microcirculation indicators, even a year after treatment, the indicators characterizing the degree of inflammatory and microcirculatory disorders in the gums retained significant differences compared to the values obtained before the treatment.

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