Handedness-controlled and solvent-driven actuators with twisted fibers

2019 ◽  
Vol 6 (6) ◽  
pp. 1207-1214 ◽  
Author(s):  
Bo Fang ◽  
Youhua Xiao ◽  
Zhen Xu ◽  
Dan Chang ◽  
Bo Wang ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Kinetic Energy ◽  
Energy Conversion ◽  
Conversion Coefficient ◽  
Mechanical Energy ◽  
Electrical Energy ◽  
High Energy ◽  
Polar Solvents ◽  
Start Up

Handedness-controlled actuating systems are constructed from continuous twisted fibers with mirrored handedness, superb flexibility and mechanical robustness, affording impressive start-up torques driven by polar solvents, and controllably outputting rotor kinetic energy, harvesting electrical energy, and delivering mechanical energy with a high energy conversion coefficient.

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.

scholarly journals Wind power plant resilience

2010 ◽  
Vol 14 (2) ◽  
pp. 533-540 ◽  
Author(s):  
Naim Afgan ◽  
Dejan Cvetinovic
Keyword(s):  
Power Plant ◽  
Kinetic Energy ◽  
Energy Conversion ◽  
Wind Power ◽  
Wind Velocity ◽  
Mechanical Energy ◽  
Electrical Energy ◽  
Wind Power Plant ◽  
Electricity Cost ◽  
Resilience Index

A wind energy system transforms the kinetic energy of wind into mechanical or electrical energy that can be harnessed for practical use. Mechanical energy is most commonly used for pumping water in rural or remote locations. Electrical energy is obtained by connecting wind turbine with the electricity generator. The performance of the wind power plant depends on the wind kinetic energy. It depends on the number of design parameter of the wind turbine. For the wind power plant the wind kinetic energy conversion depends on the average wind velocity, mechanical energy conversion into electricity, and electricity transmission. Resilience of the wind power plant is the capacity of the system to withstand changes of the following parameters: wind velocity, mechanical energy conversion into electricity, electricity transmission efficiency and electricity cost. Resilience index comprise following indicators: change in wind velocity, change in mechanical energy conversion efficiency, change in conversion factor, change in transmission efficiency, and change in electricity cost. The demonstration of the resilience index monitoring is presented by using following indicators, namely: average wind velocity, power production, efficiency of electricity production, and power-frequency change. In evaluation of the resilience index of wind power plants special attention is devoted to the determination of the resilience index for situation with priority given to individual indicators.

A Micro Kinetic Energy Harvester Demonstrating Energy Harvesting From 3-D Mechanical Motion and Power Increasing Through Magnetic-Based Frequency Rectification

2012 ◽  
Author(s):  
Tien-Kan Chung ◽  
Chieh-Min Wang ◽  
Chia-Yuan Tseng ◽  
Tzu-Wei Liu ◽  
Po-Chen Yeh
Keyword(s):  
Energy Harvesting ◽  
Kinetic Energy ◽  
Vibration Frequency ◽  
Energy Harvester ◽  
Mechanical Energy ◽  
Electrical Energy ◽  
Mechanical Motion ◽  
Voltage Output ◽  
Contact Frequency ◽  
Frequency Rectification

In this paper, we report a micro 3-D kinetic energy harvester demonstrating an energy conversion from environmental mechanical-energy (3-D mechanical motion) to electrical energy (voltage output). In addition to energy harvesting/conversion from 3-D motion, we demonstrate a non-contact frequency-up rectification approach which converts an incoming lower vibration frequency to a higher frequency in order to increase the power output of the harvester.

scholarly journals FISIKA KONTEKSTUAL PEMBANGKIT LISTRIK TENAGA MIKROHIDRO

2020 ◽  
Vol 6 (1) ◽  
pp. 142
Author(s):  
Richardo Barry Astro ◽  
Hamsa Doa ◽  
Hendro Hendro
Keyword(s):  
Kinetic Energy ◽  
Energy Conversion ◽  
Power Plants ◽  
Mechanical Energy ◽  
Electrical Energy ◽  
Impulse Turbine ◽  
Before And After ◽  
Water Turbine ◽  
Working Principle ◽  
Main Components

ABSTRAKPenelitian ini bertujuan untuk mengetahui prinsip dasar dan sistem kerja pembangkit listrik tenaga mikrohidro (PLTMH) dari sudut pandang fisika sebagai upaya penyediaan dan pengembangan sumber belajar kontekstual. Penelitian ini dilaksanakan menggunakan metode studi literatur, observasi, dan wawancara. Hasilnya ditemukan bahwa PLTMH memiliki tiga komponen utama yakni air sebagai sumber energi, turbin, dan generator. Skema konversi energi pada PLTMH yang menggunakan head adalah sebagai berikut: 1) energi potensial air dari reservoir diubah menjadi energi kinetik pada pipa pesat, 2) energi kinetik air diubah menjadi energi mekanik oleh turbin air, 3) energi mekanik diubah menjadi energi listrik oleh generator. Turbin air berdasarkan prinsip kerja dibagi atas turbin impuls dan turbin reaksi. Turbin impuls memanfaatkan perubahan momentum air sebelum dan setelah menabrak sudu turbin, sedangkan turbin reaksi memanfaatkan perbedaan tekanan pada permukaan sudu. Generator bekerja berdasarkan prinsip induksi elektromagnetik. Ketika rotor generator yang terkopel pada turbin berputar, kumparan konduktor akan memotong garis medan magnet sehingga timbul tegangan induksi. Kata kunci: pembangkit listrik tenaga mikrohidro; konversi energi; turbin, generator. ABSTRACTThe research aims to determine the fundamental principles and working systems of Microhydro power plants from a physical standpoint as an effort to provide and develop contextual learning resources. This study was conducted using literature, observation and interview methods. The results found that PLTMH had three main components i.e. water as energy source, turbine, and generator. The energy conversion scheme on PLTMH that uses the head is as follows: 1) The potential energy of water from the reservoir is converted into kinetic energy on the rapid pipeline, 2) water kinetic energy converted into mechanical energy by water turbine, 3) changed mechanical energy into electrical energy by generators. The water turbine based on the working principle is divided into impulse turbines and reaction turbines. The impulse turbine utilizes a change in water momentum before and after crashing the turbine's sudu, while the reaction turbine utilizes pressure differences on the surface of the Sudu. The generators work based on electromagnetic induction principles. When the rotor generator is attached to the turbine spinning, the conductor coil will cut off the magnetic field line so that the induction voltage arises. Keywords: microhydro power plant; energy conversion; turbine; generator.

scholarly journals Performance Characteristics in Runner of an Impulse Water Turbine with Splitter Blade

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 303
Author(s):  
Lingdi Tang ◽  
Shouqi Yuan ◽  
Yue Tang ◽  
Zhijun Gao
Keyword(s):  
Energy Conversion ◽  
Flow Direction ◽  
Mechanical Energy ◽  
Experimental Tests ◽  
High Energy ◽  
Negative Energy ◽  
Water Turbine ◽  
Conversion Performance ◽  
Water Turbines ◽  
Current Energy

The impulse water turbine is a promising energy conversion device that can be used as mechanical power or a micro hydro generator, and its application can effectively ease the current energy crisis. This paper aims to clarify the mechanism of liquid acting on runner blades, the hydraulic performance, and energy conversion characteristics in the runner domain of an impulse water turbine with a splitter blade by using experimental tests and numerical simulations. The runner was divided into seven areas along the flow direction, and the power variation in the runner domain was analyzed to reflect its energy conversion characteristics. The obtained results indicate that the critical area of the runner for doing the work is in the front half of the blades, while the rear area of the blades does relatively little work and even consumes the mechanical energy of the runner to produce negative work. The high energy area is concentrated in the flow passage facing the nozzle. The energy is gradually evenly distributed from the runner inlet to the runner outlet, and the negative energy caused by flow separation with high probability is gradually reduced. The clarification of the energy conversion performance is of great significance to improve the design of impulse water turbines.

Energy harvesting from quasi-static deformations via bilaterally constrained strips

2018 ◽  
Vol 29 (18) ◽  
pp. 3572-3581
Author(s):  
Suihan Liu ◽  
Ali Imani Azad ◽  
Rigoberto Burgueño
Keyword(s):  
Energy Harvesting ◽  
Low Power ◽  
Mechanical Energy ◽  
Electrical Power ◽  
Energy Resource ◽  
Electrical Energy ◽  
Piezoelectric Energy Harvesting ◽  
Power Budget ◽  
Piezoelectric Energy ◽  
Static Conditions

Piezoelectric energy harvesting from ambient vibrations is well studied, but harvesting from quasi-static responses is not yet fully explored. The lack of attention is because quasi-static actions are much slower than the resonance frequency of piezoelectric oscillators to achieve optimal outputs; however, they can be a common mechanical energy resource: from large civil structure deformations to biomechanical motions. The recent advances in bio-micro-electro-mechanical systems and wireless sensor technologies are motivating the study of piezoelectric energy harvesting from quasi-static conditions for low-power budget devices. This article presents a new approach of using quasi-static deformations to generate electrical power through an axially compressed bilaterally constrained strip with an attached piezoelectric layer. A theoretical model was developed to predict the strain distribution of the strip’s buckled configuration for calculating the electrical energy generation. Results from an experimental investigation and finite element simulations are in good agreement with the theoretical study. Test results from a prototyped device showed that a peak output power of 1.33 μW/cm2 was generated, which can adequately provide power supply for low-power budget devices. And a parametric study was also conducted to provide design guidance on selecting the dimensions of a device based on the external embedding structure.

scholarly journals Utilization of a magnetic field-driven microscopic motion for piezoelectric energy harvesting

Nanoscale ◽  
2019 ◽  
Vol 11 (43) ◽  
pp. 20527-20533 ◽  
Author(s):  
Sanggon Kim ◽  
Gerardo Ico ◽  
Yaocai Bai ◽  
Steve Yang ◽  
Jung-Ho Lee ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Nanoparticles ◽  
Energy Harvesting ◽  
Energy Conversion ◽  
Particle Shape ◽  
Electrical Energy ◽  
Piezoelectric Energy Harvesting ◽  
Dependent Manner ◽  
Piezoelectric Energy

Magneto–mechano–electrical energy conversion in poly(vinylidenefluoride-trifluoroethylene) piezoelectric nanofibers integrated with magnetic nanoparticles in a particle-shape dependent manner.

scholarly journals Hollow Piezoelectric Ceramic Fibers for Energy Harvesting Fabrics

2013 ◽  
Vol 8 (1) ◽  
pp. 155892501300800
Author(s):  
François M. Guillot ◽  
Haskell W. Beckham ◽  
Johannes Leisen
Keyword(s):  
Energy Harvesting ◽  
Lead Zirconate Titanate ◽  
Mechanical Energy ◽  
Electrical Power ◽  
Electrical Energy ◽  
Lead Zirconate ◽  
Ceramic Fibers ◽  
Power Sources ◽  
Electromechanical Performance ◽  
Alternative Power

In the past few years, the growing need for alternative power sources has generated considerable interest in the field of energy harvesting. A particularly exciting possibility within that field is the development of fabrics capable of harnessing mechanical energy and delivering electrical power to sensors and wearable devices. This study presents an evaluation of the electromechanical performance of hollow lead zirconate titanate (PZT) fibers as the basis for the construction of such fabrics. The fibers feature individual polymer claddings surrounding electrodes directly deposited onto both inside and outside ceramic surfaces. This configuration optimizes the amount of electrical energy available by placing the electrodes in direct contact with the surface of the material and by maximizing the active piezoelectric volume. Hollow fibers were electroded, encapsulated in a polymer cladding, poled and characterized in terms of their electromechanical properties. They were then glued to a vibrating cantilever beam equipped with a strain gauge, and their energy harvesting performance was measured. It was found that the fibers generated twice as much energy density as commercial state-of-the-art flexible composite sensors. Finally, the influence of the polymer cladding on the strain transmission to the fiber was evaluated. These fibers have the potential to be woven into fabrics that could harvest mechanical energy from the environment and could eventually be integrated into clothing.

Optimizing the Electrical Power in an Energy Harvesting System

2015 ◽  
Vol 25 (12) ◽  
pp. 1550171 ◽  
Author(s):  
Mattia Coccolo ◽  
Grzegorz Litak ◽  
Jesús M. Seoane ◽  
Miguel A. F. Sanjuán
Keyword(s):  
Energy Harvesting ◽  
Kinetic Energy ◽  
High Frequency ◽  
Energy Harvester ◽  
Electrical Power ◽  
Low Frequency ◽  
Electrical Energy ◽  
Resonance Phenomenon ◽  
Vibrational Resonance ◽  
Energy Harvesting System

In this paper, we study the vibrational resonance (VR) phenomenon as a useful mechanism for energy harvesting purposes. A system, driven by a low frequency and a high frequency forcing, can give birth to the vibrational resonance phenomenon, when the two forcing amplitudes resonate and a maximum in amplitude is reached. We apply this idea to a bistable oscillator that can convert environmental kinetic energy into electrical energy, that is, an energy harvester. Normally, the VR phenomenon is studied in terms of the forcing amplitudes or of the frequencies, that are not always easy to adjust and change. Here, we study the VR generated by tuning another parameter that is possible to manipulate when the forcing values depend on the environmental conditions. We have investigated the dependence of the maximum response due to the VR for small and large variations in the forcing amplitudes and frequencies. Besides, we have plotted color coded figures in the space of the two forcing amplitudes, in which it is possible to appreciate different patterns in the electrical power generated by the system. These patterns provide useful information on the forcing amplitudes in order to produce the optimal electrical power.

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