Piezoelectric Energy Harvesting Technology Research Articles

Optimization of Non-Uniform Deformation on Piezoelectric Circular Diaphragm Energy Harvester with a Ring-Shaped Ceramic Disk.

Piezoelectric energy harvesting technology using the piezoelectric circular diaphragm (PCD) has drawn much attention because it has great application potential in replacing chemical batteries to power microelectronic devices. In this article, we have found a non-uniform strain distribution inside the PCD energy harvester. From the edge to the center of the ceramic disk, its output voltage first increases and then decreases. This uneven output voltage reduces the output power of the PCD energy harvester. Based on this phenomenon, we reduce the ceramic disk diameter and dig a hole in the center, analyzing the effect of removing the ceramic disk’s low output voltage part on the PCD energy harvester. The experimental results show that removing the ceramic disk’s low output voltage part can improve the output power, reduce the resonance frequency, and increase the optimal impedance of the PCD energy harvester. Under the conditions of 10 g proof mass, 9.8 m/s2 acceleration, the PCD energy harvester with a 19-mm diameter and a 6-mm hole can reach a maximum output power of 8.34 mW.

Mechanistic Modeling and Economic Analysis of Piezoelectric Energy Harvesting Potential in Airport Pavements

This study investigated the feasibility of applying piezoelectric energy harvesting technology in airfield pavements through mechanistic modeling and economic analysis. The energy harvesting performance of piezoelectric transducers was evaluated based on mechanical energy induced by multi-wheel aircraft loading on flexible airfield pavements. A three-dimensional finite element model was used to estimate the stress pulse and magnitude under moving aircraft tire loading. A stack piezoelectric transducer design was used to estimate the power output of a piezoelectric harvester embedded at different locations and depths in the pavement. The aircraft load and speed were found to be vital factors affecting the power output, along with the installation depth and horizontal locations of the energy harvester. On the other hand, the installation of the energy module had a negligible influence on the horizontal tensile strains at the bottom of the asphalt layer and compressive strains on the top of the subgrade. However, the near-surface pavement strains increased when the edge ribs of the tire were loaded on the energy module. Feasibility analysis results showed that the calculated levelized cost of electricity was high in general, although it varies depending on the airport traffic levels and the service life of the energy module. With the development of piezoelectric materials and technology, further evaluation of energy harvesting applications at airports needs to be conducted.

Experimental Frequency Tuning Methodology of a Cantilever Piezoelectric Harvester Validated in a Multimodal Transportation

Piezoelectric energy harvesting is a promising technology that increases the autonomy of low power IoT devices in scenarios that are subjected to mechanical vibrations. This work shows the potential of this technology to power IoT devices with the energy that is harvested from vibrations occurred during air and road transportation. Adjusting the natural resonance frequency of the piezoelectric generator (PEG) to the mechanical acceleration frequency that has the highest power spectral density is key to increase the harvested energy. Therefore, in this work a commercial PEG is tuned to the best spectrogram frequency of a real vibration signal following a two-phase tuning process. The harvested power generated by the PEG has been validated in real scenarios, providing 2.4 μ Wh during flight (take-off, cruise flight, and landing), 11.3 μ Wh during truck transportation in urban areas, and 4.8 μ Wh during intercity transportation. The PEG has been embedded in an ultra-low power IoT device to validate how much this harvested energy can increase the autonomy in a real scenario that is subjected to similar vibrations. An NFC temperature data logger is developed for perishable products that are transported by air and road transports. The energy harvested by the PEG tuned with the methodology proposed in this work has increased the autonomy of the data logger 16.7% during a real use case of 30 h, which validates the potential of the piezoelectric energy harvesting technology to increase the autonomy of future low power IoT devices used in scenarios with aperiodic vibrations.

A Review of Human-Powered Energy Harvesting for Smart Electronics: Recent Progress and Challenges

Recently, energy harvesting from human motion has attracted substantial research into its ability to replace conventional batteries for smart electronics. Human motion exhibits excellent potential to provide sustainable and clean energy for powering low-powered electronics, such as portable instruments and wearable devices. This review article reports on the piezoelectric, electromagnetic, and triboelectric energy harvesting technologies that can effectively scavenge biomechanical energy from human motion such as, walking, stretching, and human limb movement, as well as from small displacements (e.g., heartbeat, respiration, and muscle movement) inside the human body. Furthermore, various recent designs and configurations of human motion energy harvesters are presented according to their working mechanisms, device compositions, and performances. In order to provide insight into future research prospects, the paper also discusses the limitations, issues, and challenges of piezoelectric, electromagnetic, and triboelectric energy harvesting technologies for the development of smart electronics.

Performance of a speed bump piezoelectric energy harvester for an automatic cellphone charging system

We propose a piezoelectric energy harvesting technology installed in a roadway speed bump. We have installed a module that can charge mobile phones utilizing a speed bump piezoelectric harvester (SBPH), which is easy to apply to roads. A highly integrated module with 40 piezo-generators was fixed and installed at the center of the speed bump. When a medium-sized vehicle passed the module at a speed of 30 km/h, an output voltage of 144 Vmax, output current of 45.2 mAmax, and output power of 4086.08 mWmax (6.81 W/m2) were measured at a load resistance of 2 kΩ. When the vehicle passed over the SBPH nine times, it charged a capacitor (10,000 μF) to provide 6 V for about 200 s, and the charged electrical energy was enough to operate a cellphone. The self-controlled battery charging system via electricity generated by the piezoelectric module could be applied to a speed bump installed on an actual road.

Watts-level road-compatible piezoelectric energy harvester for a self-powered temperature monitoring system on an actual roadway

Piezoelectric energy harvesting technology can be used for a wide range of purposes through the design of road energy harvesting devices. For the roadway piezoelectric energy harvester (RPEH) developed here, a piezoelectric energy harvester (PEH) is fixed at both ends to increase the tolerable load and a module durable against harsh highway environments were developed using aluminum plates, steel plates, and polypropylene bars. A maximum voltage of 66 V, maximum current of 30.37 mA and maximum output power of 830 mW were measured with 2 mm of displacement at 15 Hz using the RPEH (50 cm × 20 cm) with 80 PEH units connected in parallel. On an actual high-speed road, measurements from a medium-sized vehicle which passes the RPEH at a speed of 90 km/h record an output voltage of 46.52 Vmax, output current of 93.04 mAmax, and power of 4.3 Wmax (power density: 43.0 W/m2) at a load resistance level of 0.5 kΩ. In an actual roadway environment, the electrical energy generated by the RPEH is sufficient to operate a temperature sensor and to transmit data wirelessly.

Research Status and Development Direction of Piezoelectric Wind Energy Harvesting Technology

In recent years, with the rapid development of large-scale distributed wireless sensor systems and micro-power devices, the disadvantages of traditional chemical battery power supply mode are becoming more and more obvious. Piezoelectric energy collector has attracted wide attention because of its simple structure, no heating, no electromagnetic interference, environmental protection and easy miniaturization. Wind energy is a reproducible resource. Wind energy harvester based on piezoelectric intelligent material can be named piezoelectric wind energy harvesting which converts wind energy into electric power and will have great application prospect. To promote the development of piezoelectric wind energy harvesting technology, research statuses on piezoelectric wind energy harvesting technology are reviewed. The existing problem and development direction about piezoelectric wind energy harvester in the future are discussed. The study will be helpful for researchers engaged in piezoelectric wind energy harvesting.

A comprehensive review on piezoelectric energy harvesting technology: Materials, mechanisms, and applications

The last decade has witnessed significant advances in energy harvesting technologies as a possible alternative to provide a continuous power supply for small, low-power devices in applications, such as wireless sensing, data transmission, actuation, and medical implants. Piezoelectric energy harvesting (PEH) has been a salient topic in the literature and has attracted widespread attention from researchers due to its advantages of simple architecture, high power density, and good scalability. This paper presents a comprehensive review on the state-of-the-art of piezoelectric energy harvesting. Various key aspects to improve the overall performance of a PEH device are discussed, including basic fundamentals and configurations, materials and fabrication, performance enhancement mechanisms, applications, and future outlooks.

A High Efficient Piezoelectric Windmill using Magnetic Force for Low Wind Speed in Wireless Sensor Networks

An innovative small-scale piezoelectric energy harvester has been proposed to gather wind energy. A conventional horizontal-axis wind power generation has a low generating efficiency at low wind speed. To overcome this weakness, we designed a piezoelectric windmill optimized at low-speed wind. A piezoelectric device having high energy conversion efficiency is used in a small windmill. The maximum output power of the windmill was about 3.14 mW when wind speed was 1.94 m/s. Finally, the output power and the efficiency of the system were compared with a conventional wind power system. This work will be beneficial for the piezoelectric energy harvesting technology to be applied to the real world such as wireless sensor networks (WSN).

Preparation and performance research of stacked piezoelectric energy-harvesting units for pavements

The exploration and research of pavement piezoelectric energy harvesting technology provides new ideas for the collection and application of road green energy. To improve the applicability of the piezoelectric energy-harvesting units in road environment effectively, based on technical requirements of energy-harvesting units for pavements, this paper compares two processes for preparing stacked piezoelectric energy-harvesting units and evaluates their application performance in terms of electromechanical conversion performance and structural strength; and the optimal preparation process for the units is determined as well. Two detailed structure optimization schemes of U-shaped interlayer copper foil electrode structure and lateral lead electrode structure are designed, which are tested and evaluated from the three perspectives of energy output performance, working durability and material properties, and the optimal electrode structure is determined. The results indicate that at 0.7 MPa–10 Hz, the parallel connected units prepared based on the multilayer adhesive process can increase the terminal voltage by 28.0 V and the output power by 22.80 mW, which are superior than units prepared by the monolithic co-firing process. In addition, the multilayer units exhibit good structural stability and weatherability. Under the same load condition, the optimal load resistances of the units with the U-shaped interlayer copper foil electrode and the lateral lead electrode can reach 20 kΩ with comparable energy outputs. Subsequently, mechanical testing is conducted after 50,000 simulation (MTS) cyclic loading, the structural performance of the U-shaped interlayer copper foil units is relatively durable and stable: the open-circuit voltage is attenuated by 4.4 V, the output power is attenuated by 3.30 mW, and the average capacitance of a single unit is only attenuated by 3.4 nF. Finally, future research plan is discussed.

Development of wearable equipment and piezoelectric vibration energy harvest devices

With the continuous development of micro-electro-mechanical system, integrated circuit and wireless communication technology in recent years, piezoelectric vibration energy harvesting technology has been widely used in the power supply system of different scale electromechanical equipment. In particular, it is closely related to the human life wearable devices which shows the urgent demand of micro energy technology. In this paper, the basic principle and common structure of piezoelectric energy harvesting are reviewed. The main research achievements and progress of piezoelectric energy harvesting for wearable devices are analysed, and the challenges and proposed solutions for the piezoelectric energy harvesters based on wearable devices are discussed.

A Systematic Review of Energy Harvesting from Roadways by using Piezoelectric Materials Technology

Piezoelectric energy harvesting technology is attracting more attention in recent years due to the trend of finding new and green sources of energy. This project presents a state of the art review in the area of using piezoelectric materials to harvest energy from roadways. The aim of this project is to investigate the process of harvesting energy from roadways starting from the used piezoelectric materials, harvesters and the conditions of the roadways. Many papers were evaluated and analyzed to study the current progress in the area including of the efficiency and feasibility of extant work. The results were obtained from various sources under different circumstances and compared, in order to determine the most efficient outcome in terms of cost and implementation in practical applications.

All-inkjet-printed flexible piezoelectric generator made of solvent evaporation assisted BaTiO3 hybrid material

Attractive approaches based on flexible piezoelectric energy harvesting technology that convert ambient mechanical energies into electrical energy have attracted attention in response to recent progress in the field of flexible electronics technology. Although the harvesters on plastic substrates has shown the feasibility of the piezoelectric energy generation from the repetitive and tiny bending deformations, the complicated fabrication process and size limitations hinder the commercialization of piezoelectric self-powered technology. In this study, all-inkjet-printed flexible piezoelectric energy harvester based on a BaTiO3 hybrid film is demonstrated by adopting only a simple and facile inkjet-printing process. Flexible/large-area piezoelectric hybrid film and Ag electrode layers are printed onto a flexible substrate by only non-contact inkjet process without high temperature annealing and complicated transfer processes. All-inkjet-printed energy harvester converts the periodically mechanical deformations into an open-circuit voltage (Voc) of ~ 7V, a short-circuit current (Isc) of 2.5 μA (corresponding to a current density of 0.21 μA·cm−2), and an effective output power of around 5 μW (corresponding to a power density of 0.42 μW·cm−2). This novel approach provides an innovative platform for self-powered system and inorganic-based flexible electronics.

Charging capacitors using single crystal PMN-PT and PZN-PT energy harvesters coupled with the SSHI circuit

Piezoelectric energy harvesting technology is regarded as a remedy to the short-life battery issue in low-power electronic devices, and has been extensively studied in the past two decades. Although a variety of new structures and mechanisms have been proposed for piezoelectric energy harvesters (PEHs), there is not much progress made on the piezoelectric materials that play a determinant role in PEHs performance. Most energy harvesters are still constructed with lead zirconate titanate (PZT). Recently, the new-generation piezoelectric materials PMN-PT and PZN-PT single crystals are proposed and start to be used in transducers. Their electromechanical coupling factor (k33) is over 90%, and the piezoelectric coefficient (d33) can reach three times of that of PZT. This study characterizes the PMN-PT and PZN-PT single crystals used in energy harvesters, compared with the polycrystalline PZT, in terms of charging capacitors. Systematic discussions are presented on the voltage, power and energy responses, as well as the reverse coupling effect on the mechanical response and the self-discharge effect of capacitors. Furthermore, a self-powered synchronized switch harvesting on inductor (SSHI) circuit is constructed and tested with the new single-crystal based energy harvesters. Experiments indicate that PMN-PT and PZN-PT can significantly boost the charging capability of energy harvesters, and that performance can be further enhanced by the SSHI circuit.

An investigation on stress distribution effect on multi- piezoelectric energy harvesters

With the fast development of piezoelectric materials and due to its green and renewable characteristics, the piezoelectric energy harvesting technology has been paid more and more attention by pavement engineers. The stress distribution will significantly affect the piezoelectric material performance. In this paper, the effects of multiple piezoelectric elements on the generation of electrical energy and output power are studied. In the case of constant external load, the number of the piezoelectric units does not necessarily produce more energy. When the same multi piezoelectric units work together, if the stress state of the piezoelectric units is different, the total output energy affected by the connection mode. For uneven stress distribution, the optimal output mode is that each of the piezoelectric units rectified before connected in parallel.

PVDF based flexible piezoelectric nanogenerators using conjugated polymer:PCBM blend systems

Piezoelectric energy harvesting technology has received much attention as a powerful source of energy for a self-powered system. In this study, three main conjugated polymers that have delocalized π-electrons and excellent charge transport properties were studied: poly(3-hexylthiophene) (P1), poly[(4,8-di-(2-ethylhexyloxy)benzo[1,2-b:4,5-b′]dithiophene-2,6-diyl)-alt-(5,5′-yl-4,4′-bis(dodecyl)-2,2′-bithiophene)] (P2) and poly[(4,8-di-(2-ethylhexyloxy)benzo[1,2-b:4,5-b′]dithiophene-2,6-diyl)-alt-(5,5′-yl-4,4′-bis(2-ethylhexyl)-2,2′-bithiophene)] (P3). Each of three polymers was blended with phenyl-C61-butyric acid methyl ester (PCBM61), and the blend systems were used to make PVDF based piezoelectric nanogenerators (PNG-0–3). Polymers showed bimodal structures that have a majority edge-on orientation, forming a minority face-on orientation. At a 2Hz frequency and 0.2mm displacement, the output voltages (peak-to-peak) of PNG-(0–3) were 35.0V, 41.2V, 42.2V and 43.1V, respectively, and the output currents (peak-to-peak) were 558.5nA, 569.5nA, 572nA and 589nA, respectively. The energy conversion efficiencies of PNGs (0–3) were 6.47%, 11.62%, 13.36%, and 14.33%, respectively; therefore, the efficiency was improved by up to about 2.2 times.

A Preliminary Study on the IoT-Based Pavement Monitoring Platform Based on the Piezoelectric-Cantilever-Beam Powered Sensor

Green and sustainable power supply for sensors in pavement monitoring system has attracted attentions of civil engineers recently. In this paper, the piezoelectric energy harvesting technology is used to provide the power for the acceleration sensor and Radio Frequency (RF) communication. The developed piezoelectric bimorph cantilever beam is used for collecting the vibrational energy. The energy collection circuit is used to charge the battery, where the power can achieve 1.68 mW and can meet the power need of acceleration sensor for data collection and transmission in one operation cycle, that is, 32.8 seconds. Based on the piezoelectric-cantilever-beam powered sensor, the preliminary study on the IoT-based pavement monitoring platform is suggested, which provides a new applicable approach for civil infrastructure health monitoring.

Dynamic responses of SMA-epoxy composites and application for piezoelectric energy harvesting

Piezoelectric energy harvesting technologies provide effective measures for energy supply of wireless sensor network. In this work, shape memory alloy (SMA) reinforced epoxy composites was designed as the substructure of vibration energy harvester. Based on Hamilton’s variational principle, the theoretical model of vibration piezoelectric energy harvester was developed, and the voltage output of the energy harvester at different temperatures was simulated. The varying stiffness characteristics of the SMA-epoxy composites were theoretically investigated and experimentally proved to be effective. By measuring the vibration mode of the energy harvester, we discussed the influence of SMA-epoxy and temperature on dynamic response. Through the thermal-vibration experiments, the energy harvesting behavior was analyzed. The simulation and experimental results show that the natural frequencies can be shifted to not only to the smaller direction but also to the higher frequency direction, which could be altered from 39Hz to 41.8Hz. And the theoretical prediction on energy harvesting performance considering the temperature influences of SMA-epoxy composites is proposed and the results is consistent with experimental ones.

Recent Progress on PZT Based Piezoelectric Energy Harvesting Technologies

Energy harvesting is the most effective way to respond to the energy shortage and to produce sustainable power sources from the surrounding environment. The energy harvesting technology enables scavenging electrical energy from wasted energy sources, which always exist everywhere, such as in heat, fluids, vibrations, etc. In particular, piezoelectric energy harvesting, which uses a direct energy conversion from vibrations and mechanical deformation to the electrical energy, is a promising technique to supply power sources in unattended electronic devices, wireless sensor nodes, micro-electronic devices, etc., since it has higher energy conversion efficiency and a simple structure. Up to now, various technologies, such as advanced materials, micro- and macro-mechanics, and electric circuit design, have been investigated and emerged to improve performance and conversion efficiency of the piezoelectric energy harvesters. In this paper, we focus on recent progress of piezoelectric energy harvesting technologies based on PbZrxTi1-xO3 (PZT) materials, which have the most outstanding piezoelectric properties. The advanced piezoelectric energy harvesting technologies included materials, fabrications, unique designs, and properties are introduced to understand current technical levels and suggest the future directions of piezoelectric energy harvesting.

A mathematical model for piezoelectric ring energy harvesting technology from vehicle tires

A theoretical model for a dual-mass piezoelectric ring tire harvester is developed by an iteration method to determine the energy harvested from excitations of vehicle tires by rough roads. The piezoelectric ring harvester is made of a series of discrete PZT4 patches in a square shape circumferentially embedded in a polymer ring evenly. The harvester is placed between two the steel belts tightly pasted in the inner liner of tires for the harvesting process. The influences of some practical considerations, such as the central angle θ of the tire sector to measure the contact section of a tire, the width of patches, the number of piezoelectric patches in the direction of the tire width, the thickness of patches, the radius of the piezoelectric ring, the speed of a vehicle and the road roughness, on the root mean square of the generated electric power are discussed. The results show that a power up to 42.08W can be realized from a harvester with the central angle of θ, the radius of the piezoelectric ring, the width, the thickness, and the number of the PZT4 patch in the direction of the tire width being 30°, 0.25m, 0.01m, 0.01m and 3, respectively. The research on the theoretical model develops a novel technique for an efficient and practical energy harvesting from vehicle tires.