Maximum Energy that can be Harvested from a Dielectric Elastomer Generator

2009 ◽  
Vol 1218 ◽  
Author(s):  
Adrian Koh
Keyword(s):  
Electrical Breakdown ◽  
Mechanical Energy ◽  
Electrical Energy ◽  
Dielectric Elastomer ◽  
Maximum Energy ◽  
Maximum Amount ◽  
Biaxial Stretching ◽  
Modes Of Failure ◽  
Electromechanical Instability

AbstractMechanical energy can be converted to electrical energy using a dielectric elastomer generator (DEG). The maximum amount of energy that can be harvested from a DEG is constrained by various modes of failure and operational limits. Known limiting mechanisms include electrical breakdown, electromechanical instability, loss of tension and rupture by stretch. These limits define a cycle where maximum energy can be harvested. The cycle was represented on work-conjugate planes, which can be used as a guide for the design of practical cycles. The amount of energy harvested is larger when a DEG is subject to equal-biaxial stretching.

Electromechanical Bistable Behavior of a Novel Dielectric Elastomer Actuator

2013 ◽  
Vol 81 (4) ◽  
Author(s):  
Tiefeng Li ◽  
Zhanan Zou ◽  
Guoyong Mao ◽  
Shaoxing Qu
Keyword(s):  
High Voltage ◽  
Electrical Breakdown ◽  
Mechanical Energy ◽  
Electrical Energy ◽  
High Voltage Pulse ◽  
Dielectric Elastomer ◽  
Small Scale ◽  
Practical Applications ◽  
Design And Optimization ◽  
Bistable Structure

High voltage is required for the existing dielectric elastomer (DE) actuators to convert electrical energy to mechanical energy. However, maintaining high voltage on DE membranes can cause various failures, such as current leakage and electrical breakdown, which limits their practical applications, especially in small-scale devices. To overcome the above drawback of DE actuators, this paper proposes a new actuation method using DE membranes with a properly designed bistable structure. Experiment shows that the actuator only requires a high-voltage pulse to drive the structure forward and backward with electromechanical snap-through instability. The actuator can maintain its stroke when the voltage is removed. An analytical model based on continuum mechanics is developed, showing good agreement with experiment. The study may inspire the design and optimization of DE transducers.

Dielectric Elastomer Energy Harvesting and its Application to Human Walking

2011 ◽  
Author(s):  
Heather Lai ◽  
Chin An Tan ◽  
Yong Xu
Keyword(s):  
Energy Harvesting ◽  
Knee Joint ◽  
Mechanical Energy ◽  
Electrical Energy ◽  
High Energy ◽  
Dielectric Elastomer ◽  
Metabolic Energy ◽  
High Energy Density ◽  
Human Walking ◽  
Wide Range

Human walking requires sophisticated coordination of muscles, tendons, and ligaments working together to provide a constantly changing combination of force, stiffness and damping. In particular, the human knee joint acts as a variable damper, dissipating greater amounts of energy when the knee undergoes large rotational displacements during walking, running or hopping. Typically, this damping results from the dissipation, or loss, of metabolic energy. It has been proven to be possible however; to collect this otherwise wasted energy through the use of electromechanical transducers of several different types which convert mechanical energy to electrical energy. When properly controlled, this type of device not only provides desirable structural damping effects, but the energy generated can be stored for use in a wide range of applications. A novel approach to an energy harvesting knee joint damper is presented using a dielectric elastomer (DE) smart material based electromechanical transducer. Dielectric elastomers are extremely elastic materials with high electrical permittivity which operate based on electrostatic effects. By placing compliant electrodes on either side of a dielectric elastomer film, a specialized capacitor is created, which couples mechanical and electrical energy using induced electrostatic stresses. Dielectric elastomer energy harvesting devices not only have a high energy density, but the material properties are similar to that of human tissue, making it highly suitable for wearable applications. A theoretical framework for dielectric elastomer energy harvesting is presented along with a mapping of the active phases of the energy harvesting to the appropriate phases of the walking stride. Experimental results demonstrating the energy harvesting capability of a DE generator undergoing strains similar to those experienced during walking are provided for the purpose of verifying the theoretical results. The work presented here can be applied to devices for use in rehabilitation of patients with muscular dysfunction and transfemoral prosthesis as well as energy generation for able-bodied wearers.

The Electromechanical Behavior of Dielectric Elastomer Actuator Stiffened by Fiber

2018 ◽  
Vol 765 ◽  
pp. 12-15 ◽  
Author(s):  
Long Zhou Lyu ◽  
Shi Jie Zhu
Keyword(s):  
Applied Voltage ◽  
Applied Load ◽  
Mechanical Energy ◽  
Electrical Energy ◽  
Dielectric Elastomer ◽  
Functional Material ◽  
Dielectric Elastomer Actuator ◽  
Electromechanical Behavior ◽  
Electromechanical Performance

Dielectric elastomer is functional material that can convert electrical energy to mechanical energy. In this paper, a cylindrical dielectric elastomer actuator was designed and fabricated by using fiber stiffening to improve its electromechanical performance. the effects of pre-straining, rate of applied voltage and fiber stiffening on the electromechanical behavior were investigated by the experiments. It was found that the best applied load for pre-straining was 524g based on the electromechanical tests at the applied voltage rate of 10V/s. The maximum actuated strain decreased with an increase in rate of applied voltage. When the fibers were embedded in the dielectric elastomer actuator, the maximum actuated strain was 27.5%, doubled the value of 14% without fiber stiffening at the applied voltage rate of 20V/s.

Manufacture and Experimental Investigation of a Multi-Layer Generator Based on Dielectric Elastomer

2014 ◽  
Vol 960-961 ◽  
pp. 1336-1341
Author(s):  
Xue Jing Liu ◽  
Gong Zhang ◽  
Yong Quan Wang ◽  
Shu Hai Jia
Keyword(s):  
Energy Harvesting ◽  
Light Emitting Diode ◽  
Electrical Energy ◽  
Dielectric Elastomer ◽  
Maximum Energy ◽  
Open Circuit ◽  
Light Emitting ◽  
Energy Harvesting Efficiency ◽  
Open Circuit Condition ◽  
Constant Charge

As a member of Electroactive Polymers (EAPs), dielectric elastomer (DE) has shown considerable potential for energy harvesting applications. After the basic principle of DE energy harvesting is studied, a multi-layer DE generator using VHB 4910 (3M, USA) is specially designed and fabricated. Then, an improved energy harvesting circuit is designed to make use of harvested electrical energy. Finally, energy harvesting experiments are implemented under the constant charge (open-circuit) condition and the results prove that the multi-layer DE generator fabricated can produce enough energy to constantly drive a light emitting diode. The harvested electrical energy has good consistent with generated electrical energy and the maximum energy harvesting efficiency ηh can reach 89%.

On the Lifetime Performance of a Styrenic Rubber Membrane for Dielectric Elastomer Transducers

2018 ◽  
Author(s):  
Chen Yi ◽  
Lorenzo Agostini ◽  
Marco Fontana ◽  
Giacomo Moretti ◽  
Rocco Vertechy
Keyword(s):  
Mechanical Energy ◽  
Experimental Studies ◽  
Electrical Energy ◽  
High Energy ◽  
Dielectric Elastomer ◽  
Rubber Membrane ◽  
Very High Energy ◽  
The Subject ◽  
Electrical Loads ◽  
Very High

Dielectric Elastomer Transducers (DETs) are solid-state electrostatic devices with variable capacitance that can convert electrical energy into mechanical energy and vice-versa. Recent theoretical and experimental studies demonstrated that DETs made of materials like silicone elastomer and natural rubber can operate at very high energy densities. Practical applicability of DETs is strongly affected by their reliability and lifetime, which depend on the maximum strain and electrical loads that are cyclically applied on such devices. To date, very little knowledge and experimental results are available on the subject. In this context, this paper reports on an extensive lifetime assessment campaign conducted on frame-stretched circular DET specimens made of a commercial styrenic rubber membrane subjected to cyclic electrical loading.

scholarly journals Dielectric Elastomer Generator for Electromechanical Energy Conversion: A Mini Review

2021 ◽  
Vol 13 (17) ◽  
pp. 9881
Author(s):  
Kui Di ◽  
Kunwei Bao ◽  
Haojie Chen ◽  
Xinjun Xie ◽  
Jianbo Tan ◽  
...  
Keyword(s):  
Large Scale ◽  
Mechanical Energy ◽  
Electrical Energy ◽  
Fast Response ◽  
High Energy ◽  
Dielectric Elastomer ◽  
Human Motion ◽  
High Energy Density ◽  
Small Scale ◽  
Electromechanical Energy Conversion

The dielectric elastomer generator (DEG) has attracted attention in converting mechanical energy into electrical energy, due to its high energy density, fast response, and light weight, which together make DEG a promising technology for electromechanical conversion. In this article, recent research papers on DEG are reviewed. First, we present the working principles, parameters, materials, and deformation modes of DEG. Then, we introduce DEG prototypes in the field of collecting mechanical energy, including small-scale applications for wind energy and human motion energy, and large-scale applications for wave energy. At the end of the review, we discuss the challenges and perspectives of DEG. We believe that DEG will play an important role in mechanical energy harvesting in the future.

scholarly journals OPTIMAL PIEZOELECTRIC SHUNT DAMPER USING ENHANCED SYNTHETIC INDUCTOR: SIMULATION AND EXPERIMENTAL VALIDATION

2022 ◽  
Vol 23 (1) ◽  
pp. 424-433
Author(s):  
Muhammad Nazri Suhaimi ◽  
Azni Nabela Wahid ◽  
Nor Hidayati Diyana Nordin ◽  
Khairul Affendy Md Nor
Keyword(s):  
Cantilever Beam ◽  
Mechanical Energy ◽  
Vibration Reduction ◽  
Electrical Energy ◽  
Maximum Energy ◽  
Electrical Circuit ◽  
Structural Vibration ◽  
In Series ◽  
Piezoelectric Shunt ◽  
Shunt Circuit

Piezoelectric material has the ability to convert mechanical energy to electrical energy and vice versa, making it suitable for use as an actuator and sensor. When used as a controller in sensor mode, the piezoelectric transducer is connected to an external electrical circuit where the converted electrical energy will be dissipated through Joule heat; also known as piezoelectric shunt damper (PSD). In this work, a PSD is used to dampen the first resonance of a cantilever beam by connecting its terminal to an RL shunt circuit configured in series. The optimal resistance and inductance values for maximum energy dissipation are determined by matching the parameters to the first resonant frequency of the cantilever beam, where R = 78.28 k? and L = 2.9 kH are found to be the optimal values. To realize the large inductance value, a synthetic inductor is utilized and here, the design is enhanced by introducing a polarized capacitor to avoid impedance mismatch. The mathematical modelling of a cantilever beam attached with a PSD is derived and simulated where 70% vibration reduction is seen in COMSOL. From experimental study, the vibration reduction obtained when using the piezoelectric shunt circuit with enhanced synthetic inductor is found to be 67.4% at 15.2 Hz. Results from this study can be used to improve PSD design for structural vibration control at targeted resonance with obvious peaks. ABSTRAK: Material piezoelektrik mempunyai keupayaan mengubah tenaga mekanikal kepada tenaga elektrik dan sebaliknya, di mana ia sesuai digunakan sebagai penggerak dan pengesan. Apabila digunakan sebagai alat kawalan dalam mod pengesan, piezoelektrik disambung kepada litar elektrik luaran di mana tenaga elektrik yang ditukarkan akan dibebaskan sebagai haba Joule; turut dikenali sebagai peredam alihan piezoelektrik (PSD). Kajian ini menggunakan PSD sebagai peredam resonan pertama pada palang kantilever dengan menyambungkan terminal kepada litar peredam RL bersiri. Rintangan optimal dan nilai aruhan bagi tenaga maksimum yang dibebaskan terhasil dengan membuat padanan parameter pada frekuensi resonan pertama palang kantilever, di mana R = 78.28 k? dan L = 2.9 kH adalah nilai optimum. Bagi merealisasikan nilai aruhan besar, peraruh buatan telah digunakan dan di sini, rekaan ini ditambah baik dengan memperkenalkan peraruh polaris bagi mengelak ketidakpadanan impedans. Model matematik palang kantilever yang bersambung pada PSD telah diterbit dan disimulasi, di mana 70% getaran berkurang pada COMSOL. Hasil dapatan eksperimen ini menunjukkan pengurangan getaran yang terhasil menggunakan litar peredam piezoelektrik bersama peraruh buatan menghasilkan 67.4% pada 15.2 Hz. Hasil dapatan kajian ini dapat digunakan bagi membaiki rekaan PSD berstruktur kawalan getaran iaitu pada resonan tumpuan di puncak ketara.

scholarly journals Methods to Improve Energy Conversion Efficiency of Dielectric Elastomer Generators

2019 ◽  
Vol 804 ◽  
pp. 63-67
Author(s):  
Heng Tong Cheng ◽  
Zhen Qiang Song ◽  
Shijie Zhu ◽  
Kazuhiro Ohyama
Keyword(s):  
Energy Conversion ◽  
Conversion Efficiency ◽  
Mechanical Energy ◽  
Electrical Energy ◽  
Input Voltage ◽  
Energy Conversion Efficiency ◽  
Stretch Ratio ◽  
Dielectric Elastomer ◽  
Conversion Performance ◽  
Ratio Range

Dielectric elastomer generators (DEGs) are based on the electromechanical response of the dielectric elastomer film sandwiched between the compliant electrodes on each side, which are capable of converting mechanical energy from diverse sources (e.g, ocean wave) into electrical energy. In essence, DEG is a voltage up-converter using mechanical energy to increase the electrical energy of the charge on a soft capacitor. We evaluated the effect of input voltage and the pre-stretch ratios on energy conversion efficiency of DEG. With a power supply of 2.2kV and pre-stretch ratio of 2, the maximum net electrical energy density and energy conversion efficiency in a single harvesting cycle were measured to be 413 J/kg and 15.8%, respectively. The experimental results showed that, with the higher input voltage and the larger stretch ratio range, higher the energy conversion performance of DEG can be achieved.

Model-Based Optimization and Characterization of DEAP Multilayer Stack-Actuators

2014 ◽  
Author(s):  
Thorben Hoffstadt ◽  
Jürgen Maas
Keyword(s):  
Mechanical Energy ◽  
Electric Energy ◽  
Electrical Energy ◽  
Electroactive Polymers ◽  
Design Parameters ◽  
Optimal Operating ◽  
Electromechanical Instability ◽  
Electrostatic Pressure ◽  
Multilayer Actuators

Actuators based on dielectric electroactive polymers (DEAP) use the electrostatic pressure to convert electrical into mechanical energy. Stack-actuators are a common approach to realize DEAP-based multilayer actuators. To optimize the stationary generated force and stretch the influences of material and free design parameters are investigated based on a model of a loss-free actuator. For this purpose the stretch-force-behavior depending on the applied electric energy is introduced. Based on this approach, besides the general scalability of the force and stretch, an optimal operating point can be determined at which the ratio of generated mechanical work to the applied electrical energy is maximized. To further consider performance limitations of such actuators the known effect of electromechanical instability is finally investigated depending on the generated force yielding to critical stretches, forces and energies.

Reduction of structural vibrations with the piezoelectric stacks ring

2020 ◽  
Vol 64 (1-4) ◽  
pp. 729-736
Author(s):  
Jincheng He ◽  
Xing Tan ◽  
Wang Tao ◽  
Xinhai Wu ◽  
Huan He ◽  
...  
Keyword(s):  
Vibration Control ◽  
Mechanical Energy ◽  
Electrical Energy ◽  
Structural Vibrations ◽  
Rotor Systems ◽  
Fea Model ◽  
Piezoelectric Stacks ◽  
Shunt Damping ◽  
Reduction Effect ◽  
Euler Bernoulli Beam

It is known that piezoelectric material shunted with external circuits can convert mechanical energy to electrical energy, which is so called piezoelectric shunt damping technology. In this paper, a piezoelectric stacks ring (PSR) is designed for vibration control of beams and rotor systems. A relative simple electromechanical model of an Euler Bernoulli beam supported by two piezoelectric stacks shunted with resonant RL circuits is established. The equation of motion of such simplified system has been derived using Hamilton’s principle. A more realistic FEA model is developed. The numerical analysis is carried out using COMSOL® and the simulation results show a significant reduction of vibration amplitude at the specific natural frequencies. Using finite element method, the influence of circuit parameters on lateral vibration control is discussed. A preliminary experiment of a prototype PSR verifies the PSR’s vibration reduction effect.

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