scholarly journals Parametric optimization of a frequency-up-conversion piezoelectric harvester via discontinuous analysis

2020 ◽  
Vol 26 (15-16) ◽  
pp. 1241-1252 ◽  
Author(s):  
Saeed Onsorynezhad ◽  
Amin Abedini ◽  
Fengxia Wang
Keyword(s):  
Energy Harvester ◽  
High Efficiency ◽  
Excitation Frequency ◽  
Constitutive Law ◽  
Critical Parameters ◽  
Piezoelectric Bimorph ◽  
Piezoelectric Beam ◽  
Period 2 ◽  
Euler Bernoulli Beam ◽  
Piezoelectric Harvester

In this study, the dynamical and electrical behaviors of an impact-based frequency-up-conversion energy harvester were studied based on discontinuous dynamics theory. This analytical study enables us to better understand the response of an impact-based frequency-up-conversion energy harvester as system parameters change, hence, guiding us to design a high-efficiency energy harvester via optimizing the values of the critical parameters of the system. For a given base excitation, the optimum gap to maximize the output power was obtained. The energy harvester consists of a sinusoidal vibrating piezoelectric bimorph and a stopper. The equations of the piezoelectric bimorph, which was modeled as an Euler–Bernoulli beam, were obtained based on the linear piezoelectric constitutive law. The generated voltage and power of the energy harvester were obtained via discontinuous dynamics analysis. Furthermore, the bifurcation diagrams of period-1 and period-2 motions were presented as the excitation frequency varying. To better understand the effect of different parameters on the performance of our system, the bifurcation trees of the period-1 motion versus varying excitation frequency were analytically obtained for different initial gap distances between the piezoelectric beam and the stopper. In addition, the bifurcation diagram of period solutions with a constant excitation frequency and varying gap distance was also attained.

Discontinuous Dynamics of a Frequency Up-Conversion Piezoelectric Harvester

2019 ◽  
Author(s):  
Saeed Onsorynezhad ◽  
Fengxia Wang
Keyword(s):  
Energy Harvesting ◽  
Complex Dynamics ◽  
Excitation Frequency ◽  
Dynamics Analysis ◽  
Piezoelectric Bimorph ◽  
Periodic Motions ◽  
Piezoelectric Energy ◽  
Piezoelectric Beam ◽  
Period 2 ◽  
Euler Bernoulli Beam

Abstract This study investigates an impact based frequency up-conversion mechanism via discontinuous dynamics analysis. The mechanism composed of a stopper and a piezoelectric bimorph. The piezoelectric beam is subjected to a sinusoidal base excitation and impacts with the stopper. In this system, complex dynamics are induced by impacts, hence to better understand the energy harvesting performance of the piezoelectric beam, we seek the steady state periodic motions of the system. As the excitation frequency varies, the output voltage and power of the piezoelectric beam with periodic motions were obtained. The piezoelectric bimorph was modeled as an Euler-Bernoulli beam, and the linear piezoelectric constitutive equations were used to obtain the equations of the piezoelectric beam. The generated voltage and power were obtained using discontinuous dynamics analysis. In order to better analyze the energy harvesting performance of the piezoelectric energy harvester, the stable and unstable periodic motions were obtained. The bifurcation diagram of the period-1 and period-2 motions were obtained analytically as the excitation frequency varying.

Bimodal Approach of a Frequency-Up-Conversion Piezoelectric Energy Harvester

2019 ◽  
Vol 19 (08) ◽  
pp. 1950090 ◽  
Author(s):  
Fengxia Wang ◽  
Amin Abedini ◽  
Turki Alghamdi ◽  
Saeed Onsorynezhad
Keyword(s):  
Energy Harvester ◽  
Initial Conditions ◽  
Excitation Frequency ◽  
Harmonic Excitation ◽  
Piezoelectric Bimorph ◽  
Piezoelectric Energy ◽  
Piezoelectric Beam ◽  
Beam Function ◽  
Energy Harvesting Efficiency ◽  
Euler Bernoulli Beam

This paper developed an analytical model for a piezoelectric energy harvester (PEH) composed of a piezoelectric bimorph and a stopper as shown in Fig. 1, which was subjected to a harmonic excitation. Frequency-up-conversion, which has proved to improve the energy harvesting efficiency, was achieved due to the mechanical impact between the piezoelectric bimorph and the stopper. The piezoelectric bimorph was modeled as Euler–Bernoulli beam. A bi-modal approach was adopted to animate the beam stopper reaction. When the tip of the bimorph is free for motion, a cantilever beam function is adopted, while the tip encounters a stop, a clamped-pinned beam function is used to model the bimorph. The periodic solutions and their corresponding output voltage and power were obtained. With the same initial conditions and base excitations, the output energies of transient vibrations are compared for two cases: (1) without impact between the piezoelectric beam and the stopper; (2) with impact by reducing the gap distance between the piezoelectric beam and the stopper. With the purpose of maximizing the output power, from the steady-state analytical solutions, we studied the optimum gap between the piezoelectric beam and the stopper when the base excitations are fixed and initial conditions are set to zero.

Analytical Study of a Piezoelectric Frequency Up-Conversion Harvester Under Sawtooth Wave Excitation

2018 ◽  
Author(s):  
Saeed Onsorynezhad ◽  
Amin Abedini ◽  
Fengxia Wang
Keyword(s):  
Numerical Solutions ◽  
Excitation Frequency ◽  
Dynamics Analysis ◽  
Periodic Motions ◽  
Lumped Model ◽  
Sawtooth Wave ◽  
Piezoelectric Beam ◽  
Period 2 ◽  
Mass Spring ◽  
The Impact

In this work, an impact based frequency up-conversion mechanism is studied via discontinuous dynamics analysis. The mechanism consists of a moving stopper and a piezoelectric beam. The repeated free vibration of the piezoelectric beam achieved through the impaction between the stopper and the beam, With the stopper excited by a sawtooth wave. Due to the impact, the system contains complex discontinuous dynamics, hence to better understand the energy harvesting performance of the piezoelectric beam, we seek the simple periodic motions of the system. As the system parameter varies, the output voltage and power of the piezoelectric beam with periodic motions is obtained. These results were also compared with those obtained when the piezoelectric beam is directly subjected to the same sawtooth wave. The piezoelectric beam was modeled as a mass-spring-damper system, and the linear piezoelectric constitutive equations have been used to obtain the lumped model of the piezoelectric beam. In this study, numerical solutions of the generated power and voltage were obtained via discontinuous dynamics analysis. When the excitation frequency is low, the effect of frequency-up-conversion is demonstrated by comparing the generated power of two cases: piezoelectric beam excited via impact and beam directly subject to the sawtooth wave. The stable and unstable periodic motions and bifurcation trees of the impact parameters are predicted analytically versus varying excitation frequency for period-1 and period-2.

Enhanced performance of piezoelectric energy harvester through three serial vibrators

2020 ◽  
pp. 1045389X2097444
Author(s):  
Xiaobiao Shan ◽  
Haigang Tian ◽  
Tao Xie
Keyword(s):  
Energy Harvester ◽  
Flow Direction ◽  
Water Channel ◽  
Water Environment ◽  
Inhibitory Effect ◽  
Piezoelectric Energy ◽  
Piezoelectric Beam ◽  
In Series ◽  
Lock In ◽  
Piezoelectric Harvester

This paper presents a piezoelectric harvester array with three identical energy harvesting vibrators (EHVs) arranged in series along the water flow direction. Each EHV consists of a piezoelectric beam and an interference cylinder. Three serial EHVs are placed upright in the water channel. Prototypes of three EHVs are fabricated and experiments are conducted to explore the vibration response and harvesting performance. The experimental results demonstrated that three EHVs in the array show the obvious difference in excitation vibration and harvesting performance over single EHV. The lock-in frequency of three EHVs can be enhanced by the EHV array, and the speed bandwidth can be greatly broadened by accounting for 66.9%. The harvesting performance of upstream EHV (EHV-1) and downstream EHV (EHV-3) is significantly improved by the EHV array over single EHV. While, midstream EHV (EHV-2) shows an inhibitory effect to some extent. The overall harvesting performance in the EHV array can be increased by up to 36.23% compared with single EHV in certain spacing distances. The proposed EHV array shows the better harvesting ability over the previous harvesters. This work provides a comprehensive experimental guideline for further designing efficient harvester array used in low-speed water environment.

Discontinuous Dynamics of a Frequency Up-Conversion Piezoelectric Harvester With an Impact Controlling Mechanism

2020 ◽  
Author(s):  
Saeed Onsorynezhad ◽  
Fengxia Wang
Keyword(s):  
Energy Harvester ◽  
Ritz Method ◽  
Electrical Coupling ◽  
Excitation Frequency ◽  
Distributed Parameter ◽  
Piezoelectric Energy ◽  
Controlling Mechanism ◽  
The Stability ◽  
The Impact ◽  
Piezoelectric Harvester

Abstract In this study, an impact based frequency up-conversion mechanism is studied using discontinuous dynamics theory. The mechanism consists of a sinusoidal vibrating plastic beam as a driving element and a piezoelectric bimorph as a generator. In order to remove the unfavorable stick motion and enhance the performance of the energy harvester, two pairs of racks and pinion gears and a slider-crank have been added to the system, which makes us able to control the impact occurring time between the driving beam and the generator. In this work, the Rayleigh-Ritz method was applied to obtain the distributed-parameter models of the driving beam and the piezoelectric generator. Both the forward and the backward mechanical-electrical coupling effects were considered during the modeling of the generator. The electrical and mechanical dynamic behaviors of the proposed piezoelectric energy harvester were analytically studied to better understand the effect of system parameters on the performance of piezoelectric energy harvester. Discontinuous dynamics theory was applied to obtain the generated power and voltage. The stability of the periodic solutions was obtained, and the bifurcation diagrams of displacements, impact velocities, generated power, and voltage were obtained analytically as the excitation frequency varying.

Backward Mechanical-Electric Coupling Effect of a Frequency-Up-Conversion Piezoelectric Energy Harvester

2019 ◽  
Author(s):  
Fengxia Wang ◽  
Saeed Onsorynezhad
Keyword(s):  
Energy Harvester ◽  
Coupling Effect ◽  
Harmonic Excitation ◽  
Output Energy ◽  
Maximum Output ◽  
Piezoelectric Bimorph ◽  
Electric Coupling ◽  
Piezoelectric Energy ◽  
Piezoelectric Beam ◽  
Beam Function

Abstract This paper developed an analytical model for a frequency-up-conversion piezoelectric energy harvester (PEH) composed of a piezoelectric bimorph and a stopper as shown in Fig.1. The whole system was subjected to a harmonic excitation. A bimodal approach was adopted to animate the beam stopper reaction. When the tip of the bimorph vibrates in free space or impacts with the stopper, a cantilever beam function was adopted. On the other hand, if the tip of the bimorph sticks with the stopper, a clamped-pinned beam function was applied to model the piezoelectric bimorph. To exam the effect of backward mechanical-electric coupling on power output, the dynamics and output energies are compared for two cases: 1) neglecting the backward mechanical-electric coupling effect in the model; 2) including the backward mechanical-electric coupling effect in the model. To obtain maximum output energy, the steady-state analytical solutions were studied to obtain the optimum gap between the piezoelectric beam and the stopper. From the results, we found that if the beam impacts and/or sticks with the stopper, the PEH model without the backward mechanical-electric coupling will exaggerate the output energy.

Enhancing the Output Power of a Piezoelectric Energy Harvester by Reducing the Effect of the Internal Capacitance Using Inductance

2016 ◽  
Author(s):  
Anahita Zargarani ◽  
S. Nima Mahmoodi
Keyword(s):  
Power Output ◽  
Energy Harvester ◽  
Resistive Load ◽  
Inductive Load ◽  
Electrical Circuits ◽  
Piezoelectric Energy ◽  
Innovative Method ◽  
Piezoelectric Beam ◽  
Power Outputs ◽  
Piezoelectric Harvester

This paper describes an innovative method for enhancing the power output of a piezoelectric energy harvester. The proposed approach is adopting inductance to reduce the effect of the internal capacitance of the piezoelectric harvester to boost the power output. Four electrical circuits for a piezoelectric beam harvester are studied; Simple Resistive Load (SRL), Inductive Load (IL), Standard AC-DC, and Inductive AC-DC circuits. An inductor is added to the SRL and standard AC-DC circuits to build the new IL and Inductive AC-DC circuits respectively. The power outputs of the four circuits are then studied. The results show that the adaptation of inductor enhances the power output. The IL circuit enhances the power output comparing to the SRL circuit. The Inductive AC-DC circuit also avails the standard AC-DC circuit.

Power Generation From Mastication Forces Using a Smart Tooth

2016 ◽  
Author(s):  
Muath Bani-Hani ◽  
M. Amin Karami
Keyword(s):  
Energy Harvester ◽  
Pulse Generator ◽  
Exact Analytical Solution ◽  
Vibration Energy Harvester ◽  
Mechanical Coupling ◽  
Pulse Generators ◽  
Energy Harvesters ◽  
Piezoelectric Beam ◽  
Bimorph Beam ◽  
Euler Bernoulli Beam

The batteries of the current pacing devices are relatively large and occupy over 60 percent of the size of pulse generators. Therefore, they cannot be placed in the subtle areas of human body. In this paper, the mastication force and the resulting tooth pressure are converted to electricity. The pressure energy can be converted to electricity by using the piezoelectric effect. The tooth crown is used as a power autonomous pulse generator. We refer to this envisioned pulse generator as the smart tooth. The smart tooth is in the form of a dental implant. A piezoelectric vibration energy harvester is designed and modeled for this purpose. The Piezoelectric based energy harvesters investigated and analyzed in this paper initially includes a single degree of freedom piezoelectric based stack energy harvester which utilizes a harvesting circuit employing the case of a purely resistive circuit. The next step is utilizing and investigating a bimorph piezoelectric beam which is integrated/embedded in the smart tooth implant. Mastication process causes the bimorph beam to buckle or return to unbuckled condition. The transitions result in vibration of the piezoelectric beam and thus generate energy. The power estimated by the two mechanisms is in the order of hundreds of microwatts. Both scenarios of the energy harvesters are analytically modeled. The exact analytical solution of the piezoelectric beam energy harvester with Euler-Bernoulli beam assumptions is presented. The electro-mechanical coupling and the geometric nonlinearities have been included in the model for the piezoelectric beam.

scholarly journals Double-Deck Metal Solenoids 3D Integrated in Silicon Wafer for Kinetic Energy Harvester

Micromachines ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 74
Author(s):  
Nianying Wang ◽  
Ruofeng Han ◽  
Changnan Chen ◽  
Jiebin Gu ◽  
Xinxin Li
Keyword(s):  
Kinetic Energy ◽  
Power Density ◽  
Energy Harvester ◽  
High Efficiency ◽  
Vibrational Energy ◽  
Average Power ◽  
Wafer Level ◽  
Peak Voltage ◽  
Silicon Mold ◽  
Casting Technique

A silicon-chip based double-deck three-dimensional (3D) solenoidal electromagnetic (EM) kinetic energy harvester is developed to convert low-frequency (<100 Hz) vibrational energy into electricity with high efficiency. With wafer-level micro electro mechanical systems (MEMS) fabrication to form a metal casting mold and the following casting technique to rapidly (within minutes) fill molten ZnAl alloy into the pre-micromachined silicon mold, the 300-turn solenoid coils (150 turns for either inner solenoid or outer solenoid) are fabricated in silicon wafers for saw dicing into chips. A cylindrical permanent magnet is inserted into a pre-etched channel for sliding upon external vibration, which is surrounded by the solenoids. The size of the harvester chip is as small as 10.58 mm × 2.06 mm × 2.55 mm. The internal resistance of the solenoids is about 17.9 Ω. The maximum peak-to-peak voltage and average power output are measured as 120.4 mV and 43.7 μW. The EM energy harvester shows great improvement in power density, which is 786 μW/cm3 and the normalized power density is 98.3 μW/cm3/g. The EM energy harvester is verified by experiment to be able to generate electricity through various human body movements of walking, running and jumping. The wafer-level fabricated chip-style solenoidal EM harvesters are advantageous in uniform performance, small size and volume applications.

scholarly journals Analysis of a Cantilevered Piezoelectric Energy Harvester in Different Orientations for Rotational Motion

Sensors ◽  
2020 ◽  
Vol 20 (4) ◽  
pp. 1206 ◽  
Author(s):  
Wei-Jiun Su ◽  
Jia-Han Lin ◽  
Wei-Chang Li
Keyword(s):  
Theoretical Model ◽  
Resonant Frequency ◽  
Rotational Motion ◽  
Axial Load ◽  
Energy Harvester ◽  
Excitation Frequency ◽  
Experimental Studies ◽  
Piezoelectric Energy ◽  
Piezoelectric Cantilever ◽  
Tip Mass

This paper investigates a piezoelectric energy harvester that consists of a piezoelectric cantilever and a tip mass for horizontal rotational motion. Rotational motion results in centrifugal force, which causes the axial load on the beam and alters the resonant frequency of the system. The piezoelectric energy harvester is installed on a rotational hub in three orientations—inward, outward, and tilted configurations—to examine their influence on the performance of the harvester. The theoretical model of the piezoelectric energy harvester is developed to explain the dynamics of the system and experiments are conducted to validate the model. Theoretical and experimental studies are presented with various tilt angles and distances between the harvester and the rotating center. The results show that the installation distance and the tilt angle can be used to adjust the resonant frequency of the system to match the excitation frequency.

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