Mechanical Vibration Energy Research Articles

Optimizing energy harvesting performance by tailoring ferroelectric/relaxor behavior in KNN-based piezoceramics

Piezoelectric energy harvesters (PEHs) fabricated using piezoceramics could convert directly the mechanical vibration energy in the environment into electrical energy. The high piezoelectric charge coefficient (d33) and large piezoelectric voltage coefficient (g33) are key factors for the high-performance PEHs. However, high d33 and large g33 are difficult to simultaneously achieve with respect to g33 = d33/(ε0εr) and d33 = 2Qε0εrPr. Herein, the energy harvesting performance is optimized by tailoring the CaZrO3 content in (0.964−x)(K0.52Na0.48)(Nb0.96Sb0.04)O3 −0.036(Bi0.5Na0.5)ZrO3−xCaZrO3 ceramics. First, the doping CaZrO3 could enhance the dielectric relaxation due to the compositional fluctuation and structural disordering, and thus reduce the domain size to ∼30 nm for x = 0.006 sample. The nanodomains switch easily to external electric field, resulting in large polarization. Second, the rhombohedral–orthorhombic–tetragonal phases coexist in x = 0.006 sample, which reduces the polarization anisotropy and thus improves the piezoelectric properties. The multiphase coexistence structures and miniaturized domains contribute to the excellent piezoelectric properties of d33 (354 pC/N). Furthermore, the dielectric relative permittivity (εr) reduces monotonously as the CaZrO3 content increases due to the relatively low ion polarizability of Ca2+ and Zr4+. As a result, the optimized energy conversion coefficient (d33 × g33, 5508 × 10−15 m2/N) is achieved for x = 0.006 sample. Most importantly, the assembled PEH with the optimal specimen shows the excellent output power (∼48 µW) and lights up 45 red commercial light-emitting diodes (LEDs). This work demonstrates that tailoring ferroelectric/relaxor behavior in (K,Na)NbO3-based piezoelectric ceramics could effectively enhance the electrical output of PEHs.

Recent Advances in Hybrid Energy Harvesting Technologies Using Roadway Pavements: A Review of the Technical Possibility of Using Piezo-thermoelectrical Combinations

Currently, we are facing an energy transition due to pollution and depletion issues related to fossil energy sources. Among all the efforts to develop alternative green energy sources, there are other energy sources that remain unexplored. Ambient energies present on roadway pavements are one example. Thermal energy from solar radiation and the mechanical vibrations induced by passing vehicles are promising ambient energy sources available from roadway pavements. The aim of this study is to examine the existing energy harvesting systems for these ambient energy sources. This paper also summarizes existing study efforts on hybrid (thermal and mechanical vibration) energy harvesting systems in general. This hybrid system can overcome the limitations of a single source-based system as intermittent and low power generation. Energy harvesting technologies can generate green energy without negative environmental impact during the conversion process. This article solely contains references to studies examining the technological feasibility of a road energy harvesting project. Despite their importance, this bibliographic research did not include attempts to address costs, life cycle analyses, or the impact of the systems on the road structure. The reasons for this omission are due to the difficulty of obtaining this information in the scientific literature for comparison with the suggested systems.

A full-set and self-powered ammonia leakage monitor system based on CNTs-PPy and triboelectric nanogenerator for zero-carbon vessels

With the further development of ammonia as a new energy fuel, it is urgent to develop a sustainable, accurate and low power consumption detection device for ammonia leakage. In this work, a self-powered full-set ammonia leakage monitoring device has been demonstrated, containing power generation system based on a triboelectric nanogenerator (TENG), ammonia sensing system based on carbon nanotube doped polypyrrole (CNTs-PPy) and signal collecting and transmitting system. This equipment has a good application prospect on NH3-fueled ships. The TENG can harvest mechanical energy of vibration during the engine operation to power the whole sensing system. When the external load resistance is 11 MΩ, the output power density can reach to 59.783 W/m3, powered by a five-layer honeycomb structure inspired triboelectric nanogenerator (V-TENG). The ammonia sensing system has the capability to detect ammonia with a low limit of detection (0.2 ppm), short response time (about 90 s), good selectivity, excellent stability and low cost, revealing the potential application of sensor for monitoring NH3 gas under different conditions. Finally, a bluetooth module is assembled into the device, realizing the wireless transmission from the detection module to the computer terminal. The self-powered and wireless full-set device can achieve the long-term and maintenance-free detection of ammonia leakage during the ocean voyage, which will play an important role in the further application of ammonia energy.

A self-powered vibration sensor based on the coupling of triboelectric nanogenerator and electromagnetic generator

Vibration sensor that relies on the mechanical vibration of machinery to monitor its operational stability for the purpose of preventing mechanical failure and reducing the loss of life and property is of desired practical significance. Here, we propose a self-powered mechanical vibration sensor based on the coupling of electromagnetic generator (EMG) for energy harvesting and triboelectric nanogenerator (TENG) for active sensing. For EMG, a magnetic levitation system has been established that can easily respond to tiny external mechanical vibration, and the rationally designed voltage amplifier rectifier circuit as well as corresponding energy storage unit can effectively collect and store mechanical vibration energy. Furthermore, a pendulum-shaped single-electrode mode TENG can respond to vibration in the orthogonal direction and activate the pulse trigger circuit with high sensitivity. The cooperation of the two modules can realize real-time vibration monitoring and alarm signal transmission. The multi-mechanism coupled self-powered vibration sensor reported here can be applied to many scenarios, such as conveyor belt, high-speed train, and freight elevator.

Utilize mechanical vibration energy for fast thermal responsive PCMs-based energy storage systems: Prototype research by numerical simulation

For commercialisation of PCMs (liquid-solid phase change materials) based energy storage systems, the biggest challenge is to improve the thermal responsive rate of PCMs. In the present authors’ latest study, it is found mechanical vibration may be utilized to address the challenge as most engineering systems work under vibration conditions. However, to utilize mechanical vibration more efficiently, it is critical to accelerate melting speed of solid PCMs in the beginning of charging processes. In the present study, a fin is introduced for the purpose. Here comprehensive numerical simulation is conducted to reveal the effectiveness of the new combination of a fin and mechanical vibration. So far there is no open research on feasibility of this new combination. The present work bridges the gap. The present research shows the integration of a fin and mechanical vibration can provide an effective way to maintain a sustainable high thermal responsive rate for PCMs during charging processes. The fin and mechanical vibration are complementary: the fin can improve thermal responsive rate of PCMs significantly in the early period of the charging process but its influence will become weak; on the contrary, the enhancement effect of mechanical vibration is slight in the beginning but later will become strong. The effects of vibration frequency, vibration amplitude and fin length are investigated numerically. It is found a low/moderate vibration frequency can accelerate charging processes more effectively and the optimal vibration frequency range is around 0–200. And there is also an optimal range for fin length. If the ratio of fin length to side length of the cubic tank is more than 3/4, the benefit by introducing a fin will become slight, which indicates the length of fin is not the longer the better. The present work proposes a new way to develop commercial PCMs-based energy storage systems. The findings can serve as guides for realistic engineering applications.

New investigation of Micro-fluidized bed: The effect of wall roughness and particle size on hydrodynamics regimes

This study presents a new design for Micro-fluidized beds (MFBs), together with a new approach to their hydrodynamic analysis. Two 4 mm MFB reactors were manufactured from glass and resin (constructed by stereo-lithographic 3D printing), to assess the influence of wall roughness on the hydrodynamic characteristics. The novel 3D printing scheme ensures air tightness and good transparency of the reactor. Four types of glass, SiC, Al2O3 and TiO2, belonging to groups B, A/C and C from Geldart's classification, were used to investigate the influence of particle size on their fluidization behavior in MFBs. Three grades of MFB wall roughness were tested. Mechanical vibration energy was applied to the MFBs to improve the quality of fluidization, and to overcome wall friction and cohesive forces. Their hydrodynamic properties were obtained by analyzing pressure fluctuations in the time and frequency domains. The results show that only an appropriate increase in wall roughness was helpful for the suppression of slugging fluidization. The use of mechanical vibrations was found to promote the attenuation or destruction of plug phenomena, thus improving the quality of fluidization of Group A/C and C particles. The feasibility of fluidizing group A/C and C particles has thus been verified in a 3D printed MFB reactors.

Comparative evaluation of different steel for mobile nucleus of electromechanical disc type vehicle horn

A horn is a sound making device of the motor vehicle, which plays an important role for the improvement of safety. A disk type electro-mechanical horn considered in this paper utilize a complex system of electro-magnetic coils, contacts, springs and diaphragm all connected through a shaft known as mobile nucleus. Fixed nucleus is the counter part of mobile nucleus, which remains steady during application. The vibrating system and the electromagnetic system are the part of the horn and they interact through a circuit breaker, which actuated by very high frequency (300–500 cycle/second) motion of the mobile nucleus. Finally, there is an acoustic system, which aims at transforming the mechanical energy of vibrations into acoustic energy. Due to such high frequency working condition, mechanical actuators used in these devices have certain limitations and are prone to mechanical failure. Diaphragm and nucleus out of all parts considered critical. Nucleus will be continuously under high frequency fatigue, fretting fatigue with assembly and continuous impact/wear and tear with fixed nucleus. The selection of material within the interaction between the vibrating system and the electromagnetic field is useful for designing new efficient horns. Therefore, the present paper focuses on the selection of steel for mobile nucleus for longer life cycles / duration. In present paper discussing the comparative evaluation (Microstructure, Inclusion analysis, Micro hardness and Product level test failure analysis etc.) of two different mobile nucleus steel having medium (EN8D) and low carbon (C1010) were studied. The results showing that the use of medium carbon steel as an effective mobile nucleus material in electromechanical horn is superior with required fatigue properties.

Modeling and simulation of Vibro-isolator Rapid Prototyping using additive manufacturing

The emerging concept of mechanical meta-materials has gained increasing attention in recent years, partly due to advances in additive manufacturing techniques (additive manufacturing, 3D printing) that have allowed the fabrication of materials with arbitrarily complex micro / nanostructures. The designed geometry of these structures gives rise to unprecedented or rare mechanical properties that can used to create advanced elements with new, unprecedented functions. This paper presents the method of prototyping a vibro-isolator made of a material that has the properties of storing and disposing of mechanical vibration energy and that can freely be shaped by modern manufacturing techniques. An example of a vibration isolator of the proprietary concept analyzed, using the concept of stepped and adding elements. The method is based on the use of two main tools. Mechanical properties verified by analyzing the frequency and mode of free vibrations of the prototype using the finite element method. The same CAD model of the vibro-isolator prototype produced by 3D printing. The paper presents one of the production techniques, which is 3D printing in SLS (Selective Laser Sintering) technology, and the SolidWorks and Comsol Multhiphysics software used in the CAD / CAE prototyping method.

MEMS post-processed self-assembled electret for vibratory energy harvesters

Electret-based microelectromechanical system (MEMS) vibratory energy harvesting is a key technology for converting the mechanical energy of environmental vibrations into electricity. Unfortunately, conventional electret charging methods generally rely on high-voltage and high-temperature processes that present limitations to MEMS design and production. Here, we show a MEMS post-processed self-assembled electret (SAE) that enables the integration of electrets with MEMS vibratory devices via evaporation as a post-MEMS process. Owing to the spontaneous orientation of polar molecules, the surface potential of the SAE can build up at room temperature in a microscopic region without charging processes, which enhances the design and fabrication flexibility of electret-based MEMS energy harvesters. We develop a MEMS vibratory device followed by post-processing the SAE and confirm induced electrical currents caused by the electrical field of the SAE at the vibrational input. This SAE-based MEMS technology is a promising design guideline for highly integrated single-chip MEMS vibratory energy harvesters.

Design and simulation of the compact MEMS energy harvester based on aluminium nitride

A device for converting the energy of mechanical vibrations to electricity by the piezoelectric effect is presented. A main part of the transducer is a multilayer cantilever with the inertial mass at the tip. A piezoelectric layer is made of 0.5 μm thick aluminum nitride. A feature of the device is the compact lateral size of about 1 mm, which is 10 times smaller in comparison with conventional harvesters. The device is fully compatible with microelectromechanical systems (MEMS) technology. The cantilever has a natural frequency of 45-160 Hz, depending on the size and inertial mass. The transducer generates the output voltage of 0.35 V, which is high enough for rectifying by the diode bridge. The output power of 2.7 nW is relatively low due to the small size. Nevertheless, the figure of merit is higher than that for conventional AlN-based energy harvesters.

Modelling vibrations of axial piezoelectric generator with active base

Modelling of an axial-type piezoelectric generator (PEG) is considered. PEG is an integral part of the system for converting mechanical vibration energy from the environment into electrical energy. The energy generator has an axial type of the configuration of elements, aimed on using bending and compressive loads simultaneously on piezoelectric elements. The base of the generator is made as an active pinching. A feature of PEG is that the generator has two types of piezoelectric elements: (1) elements located on the substrate in the form of a bimorph and (2) piezoelectric elements of a cylindrical shape, fixing the generator base, located on the same axis. PEG has a symmetrical structure about the center of proof mass. The results of modal and harmonic analysis of vibrations are given for vibration excitation of the PEG base in a certain frequency range. The analysis of the output characteristics is given.

A Self-Powered and Battery-Free Vibrational Energy to Time Converter for Wireless Vibration Monitoring

Wireless sensor nodes (WSNs) are the fundamental part of an Internet of Things (IoT) system for detecting and transmitting data to a master node for processing. Several research studies reveal that one of the disadvantages of conventional, battery-powered WSNs, however, is that they typically require periodic maintenance. This paper aims to contribute to existing research studies on this issue by exploring a new energy-autonomous and battery-free WSN concept for monitor vibrations. The node is self-powered from the conversion of ambient mechanical vibration energy into electrical energy through a piezoelectric transducer implemented with lead-free lithium niobate piezoelectric material to also explore solutions that go towards a greener and more sustainable IoT. Instead of implementing any particular sensors, the vibration measurement system exploits the proportionality between the mechanical power generated by a piezoelectric transducer and the time taken to store it as electrical energy in a capacitor. This helps reduce the component count with respect to conventional WSNs, as well as energy consumption and production costs, while optimizing the overall node size and weight. The readout is therefore a function of the time it takes for the energy storage capacitor to charge between two constant voltage levels. The result of this work is a system that includes a specially designed lead-free piezoelectric vibrational transducer and a battery-less sensor platform with Bluetooth low energy (BLE) connectivity. The system can harvest energy in the acceleration range [0.5 g–1.2 g] and measure vibrations with a limit of detection (LoD) of 0.6 g.

A Review on Mechanical Motion Rectifier for Energy Harvesting

Abstract: The conventional vehicle suspension dissipates the mechanical vibration energy in the form of heat which waste considerable energy. The regenerative suspensions have attracted much attention in recent years for the improvement of vibration attenuating performance as well as the reduction of energy dissipation. In fact, the vibrations in some situations can be very large, for example, the vibrations of tall buildings, long vehicle systems, railroads and ocean waves. With the global concern on energy and environmental issues, energy harvesting from large-scale vibrations is more attractive. This paper introduces the existing research and significance of regenerative shock absorbers and reviews the potential of automotive vibration energy recovery techniques; then, it classifies and summarizes the general classifications of regenerative shock absorbers. Keywords: Mechanical vibration, regenerative suspension, energy dissipation, railroads, ocean waves, vehicle.

A clover shaped triboelectric nanogenerator for self-powered grip strength test system

ABSTRACT Recently, many researchers have paid attention to triboelectric nanogenerators (TENGs) to harvest mechanical energy. Thus, a clover-shaped triboelectric nanogenerator (C-TENG) was designed to obtain mechanical vibration energy and convert them into electricity. The polytetrafluoroethylene (PTFE) film and nylon film act as the triboelectric layers, and the plastic sheet serves as the supporting structure. The maximum output power of a C-TENG can arrive at 453.75 µW. In addition, the C-TENG can play the role of a self-powered sensor for reflecting handgrip strength. This design can promote the development of TENGs in mechanical energy harvesting and self-powered human sports sensors.

Biohybrid generators based on living plants and artificial leaves: influence of leaf motion and real wind outdoor energy harvesting

Plants translate wind energy into leaf fluttering and branch motion by reversible tissue deformation. Simultaneously, the outermost structure of the plant, i.e. the dielectric cuticula, and the inner ion-conductive tissue can be used to convert mechanical vibration energy, such as that produced during fluttering in the wind, into electricity by surface contact electrification and electrostatic induction. Constraining a tailored artificial leaf to a plant leaf can enhance oscillations and transient mechanical contacts and thereby increase the electricity outcome. We have studied the effects of wind-induced mechanical interactions between the leaf of a plant (Rhododendron) and a flexible silicone elastomer-based artificial leaf fixed at the petiole on power output and whether performance can be further tuned by altering the vibrational behavior of the artificial leaf. The latter is achieved by modifying a concentrated mass at the tip of the artificial leaf and observing plant-generated current and voltage signals under air flow. In this configuration, the plant-hybrid wind-energy converters can directly power light-emitting diodes and a temperature sensor. Detailed output analysis has revealed that, under all conditions, an increase in wind speed leads to nearly linearly increased voltages and currents. Accordingly, the cumulative sum energy reaches its highest values at the highest wind speed and resulting oscillations of the plant-artificial leaf system. The mass at the tip can, in most cases, be used to increase the voltage amplitude and frequency. Nevertheless, this behavior was found to depend on the individual configuration of the system, such as the leaf morphology. Analysis of these factors under controlled conditions is crucial for optimizing systems meant to operate in unstructured outdoor scenarios. We have established, in a first approach, that the artificial leaf-plant hybrid generator is capable of autonomously generating electricity outdoors under real outdoor wind conditions, even at a low average wind speed of only 1.9 m s−1.

Future Energy Source for Remote IoT Systems using MEMS-based Piezoelectric Energy Harvesting Devices.

Piezoelectric energy harvesting (PEH) device is an energy converter that will convert mechanical vibration energy into electrical energy. The energy converter is implemented using Micro-Electronic Mechanical System (MEMS). The vibration is extracted from the surroundings, and the extracted vibration is converted into electrical energy using PEH for low power sensors used in the IoT environment. PHE device will generate the maximum power when the vibration of the surrounding is exactly matched with the resonant frequency of the device. This paper presents two different PHE MEMS devices which will convert the vibration into electrical energy. The proposed device has two design materials; T shape resonant model is designed by arranging beams in multilayer and an ultra-violet resin seismic mass. There are four-layer formed together; the substrate first layer is built using polyethylene terephthalate (PET). The third layer is formed by using piezo-electric material; the second and fourth layers are build using aluminium and platinum electrode. In the model, two different types of piezoelectric materials are used to build the PEH device. Two types of material used in the devices are ZnO and PZT-5A. Rayleigh-Ritz and Macaulay methods are used to model the system for analysing the mechanical behaviour of the model and structural analysis for the better energy extraction using FEM. The proposed PHE device using ZnO and PZT-5A is generating power at the rate of 1.8 W and 1.35 W with a voltage rating of 545 and 45 mV, respectively. The Proposed PHE device is built for remote location low power IoT devices.

МОДЕЛЮВАННЯ ПРОЦЕСІВ ЕНЕРГОПЕРЕТВОРЕННЯ В СИСТЕМІ РЕКУПЕРАЦІЇ ЕНЕРГІЇ КОЛИВАНЬ ТРАНСПОРТНИХ ЗАСОБІВ

The article presents a complex mathematical model of the energy recovery system for mechanical vibrations of vehicles moving in difficult road conditions. Such a system is an auxiliary power supply system that enhances the functionality of modern vehicles. The mathematical model takes into account the entire set of processes for converting the energy of mechanical vibrations in the following sequence: mechanical energy of the reciprocating oscillatory motion of the vehicle chassis - mechanical energy of the rotational motion of the electric generator shaft - electrical energy of the alternating current of the generator - direct current electrical energy of the battery. The modes of operation of the system are investigated, which provide efficient processes of charging the battery. For a specific example, data on the charging time of a truck battery is given. References 9, figures 7.

Power Management and Reaction Optimization for a Self-Powered Electrochemical System Driven by a Triboelectric Nanogenerator.

Harvesting distributed and low-quality mechanical energies by triboelectric nanogenerators to power electrochemical reactions is beneficial to electric energy saving and certain applications. However, the conventional self-powered electrochemical process is awkward about the reaction rate, energy conversion efficiency, high-operation frequency, and mismatched impedance. Here we demonstrate an advanced self-powered electrochemical system. In comparison with the conventional system that is inert in activity, the superior power management and electrochemical reaction regulation in tandem make the novel system outstanding for hydrogen peroxide production. In addition to the visible product, an internal current efficiency of 24.6% in the system was achieved. The developed system provides an optimization strategy toward electric energy saving for electrochemical reactions as well as enabling their applications in remote areas by converting environmental mechanical vibrational energy for ecological improvement or recyclable chemical fuel generation.

Development and experimental validation of self-powered wireless vibration sensor node using vibration energy harvester

This paper deals with development of a self-powered solution for wireless vibration sensing. An autonomous operation of the proposed vibration sensor node is based on an electromagnetic energy harvesting device which converts kinetic energy of ambient mechanical vibration. Moreover, mechanical vibrations are monitored via electric signal from a piezoelectric patch and the measured signal is transmitted to the monitoring unit. The electromagnetic energy harvester is designed to provide enough power for a signal processing unit and a communication module, enabling the system to operate as a self-powered wireless vibration sensor node. Operation of this system was experimentally validated in laboratory environment and examples of vibration monitoring are presented. There is a significant restriction in terms of operation in resonance regime, where the generated power of the kinetic energy harvester is maximal and sufficient for limitless operation of the node. Main aim of this paper is to present a complex system which could be used in many engineering applications, such as aerospace, transportation, or civil structure monitoring.

Piezoelectric property investigation on PVDF/ZrO2/ZnO nanocomposite for energy harvesting application

Recent days, considerable research efforts have been emphasized on the development of lightweight, portable, shock resistance, and flexible wearable devices that are powered by harvesting energy from abundant mechanical forces or vibrational energy. In this paper, we report piezoelectric nanogenerator (PNG) based on poly (vinylidene fluoride) (PVDF)/Zirconium oxide (ZrO2)/Zinc oxide (ZnO) nanocomposite. The addition of nanofillers significantly affects the structural property of PVDF, and their addition helps in the improvement of the piezoelectric property. The PNGs are fabricated and tested under various stress conditions (at different loads, tapping and walking). The hybrid PVDF/5% ZrO2/5% ZnO nanogenerator showed a maximum peak to peak voltage (Vpp) of 3.2 V, which is nearly eight times more than pristine PVDF nanogenerator. A prototype of shoe pad nanogenerator is demonstrated as an application.