Estimation of Electric Charge Output for Piezoelectric Energy Harvesting

Abstract: Piezoelectric materials (PZT) can be used as mechanisms to transfer mechanical energy, usually ambient vibration, into electrical energy that can be stored and used to power other devices. With the recent advances in wireless and micro‐electro‐mechanical‐systems (MEMS) technology, sensors can be placed in exotic and remote locations. As these devices are wireless it becomes necessary that they have their own power supply. The power supply in most cases is the conventional battery; however, problems can occur when using batteries because of their finite life span. Because most sensors are being developed so that they can be placed in remote locations such as structural sensors on a bridge or global positioning service (GPS) tracking devices on animals in the wild, obtaining the sensor simply to replace the battery can become a very expensive task. Furthermore, in the case of sensors located on civil structures, it is often advantageous to embed them, making access impossible. Therefore, if a method of obtaining the untapped energy surrounding these sensors was implemented, significant life could be added to the power supply. One method is to use PZT materials to obtain ambient energy surrounding the test specimen. This captured energy could then be used to prolong the power supply or in the ideal case provide endless energy for the sensors lifespan. The goal of this study is to develop a model of the PZT power harvesting device. This model would simplify the design procedure necessary for determining the appropriate size and vibration levels necessary for sufficient energy to be produced and supplied to the electronic devices. An experimental verification of the model is also performed to ensure its accuracy.     

Transmissive Labyrinthine Acoustic Metamaterial-Based Holography for Extraordinary Energy Harvesting

Conventional energy sources are continuously depleting, and the world is actively seeking new green and efficient energy solutions. Enormous amounts of acoustic energy are dissipated daily, but the low intensity and limited efficiency of current harvesting techniques are preventing its adoption as a ubiquitous method of power generation. Herein, a strategic solution to increase acoustic energy harvesting efficiency using a specially designed metamaterial is implemented. A scalable transmissive labyrinthine acoustic metamaterial (LAM) is designed, developed, and employed to maximize ultrasound (40 kHz) capture over its large surface area (>27 k mm²), which is focused onto a piezoelectric film (78.6 mm²), thus magnifying incident sound pressure by 13.6 times. Three different piezoelectric films – two commercial and one lab-made nanocomposite film are tested with LAM in the acoustic energy harvesting system. An extraordinary voltage gain of 157–173% and a maximum power gain of 272% using the LAM compared to the case without the LAM are achieved. Multipoint focusing using holographic techniques, showcasing acoustic patterning to allow on-demand simultaneous harvesting in separate locations, is demonstrated. Our versatile approach for high-intensity acoustic energy harvesting opens future opportunities to exploit sound energy as a resource to contribute toward global sustainability.     

智能材料系统和结构中的压电材料

本文简述了智能和机敏材料的区别。综述了压电材料和含有压电材料作为驱动器，传感器以及压电纤维复合材料等不同智能材料系统和结构的性能及应用特征。展望了这类材料未来的发展。     

悬臂梁压电振动能采集器的集总参数模型和实验验证

压电振动能采集器是无线传感节点的一种理想电源,近年来受到广泛关注．考虑质量块和逆压电效应影响,建立了在基础激励作用下的悬臂梁压电振动能采集器的集总参数运动微分方程,得到了采集器固有频率的解析表达式．引入了2个反映压电层连接方式的常数,建立了对单压电层、双压电层并联和双压电层串联的悬臂梁压电振动能采集器均适用的耦合电路方程．求解以上方程,得到了简谐基础激励下的输出电压表达式．实验结果表明,固有频率和输出电压表达式的相对误差分别小于10％和20％．     

Recent Advancements in Nanogenerators for Energy Harvesting

Nanomaterial‐based generators are a highly promising power supply for micro/nanoscale devices, capable of directly harvesting energy from ambient sources without the need for batteries. These generators have been designed within four main types: piezoelectric, triboelectric, thermoelectric, and electret effects, and consist of ZnO‐based, silicon‐based, ferroelectric‐material‐based, polymer‐based, and graphene‐based examples. The representative achievements, current challenges, and future prospects of these nanogenerators are discussed.     

Energy Harvesting Research: The Road from Single Source to Multisource

Energy harvesting technology may be considered an ultimate solution to replace batteries and provide a long‐term power supply for wireless sensor networks. Looking back into its research history, individual energy harvesters for the conversion of single energy sources into electricity are developed first, followed by hybrid counterparts designed for use with multiple energy sources. Very recently, the concept of a truly multisource energy harvester built from only a single piece of material as the energy conversion component is proposed. This review, from the aspect of materials and device configurations, explains in detail a wide scope to give an overview of energy harvesting research. It covers single‐source devices including solar, thermal, kinetic and other types of energy harvesters, hybrid energy harvesting configurations for both single and multiple energy sources and single material, and multisource energy harvesters. It also includes the energy conversion principles of photovoltaic, electromagnetic, piezoelectric, triboelectric, electrostatic, electrostrictive, thermoelectric, pyroelectric, magnetostrictive, and dielectric devices. This is one of the most comprehensive reviews conducted to date, focusing on the entire energy harvesting research scene and providing a guide to seeking deeper and more specific research references and resources from every corner of the scientific community.     

Natural and Eco-Friendly Materials for Triboelectric Energy Harvesting

Triboelectric nanogenerators(TENGs)are promising electric energy harvesting devices as they can produce renewable clean energy using mechanical excitations from the environment.Several designs of triboelectric energy harvesters relying on biocompatible and eco-friendly natural materials have been introduced in recent years.Their ability to provide customizable self-powering for a wide range of applications,including biomedical devices,pressure and chemical sensors,and battery charging appliances,has been demonstrated.This review summarizes major advances already achieved in the field of triboelectric energy harvesting using biocompatible and eco-friendly natural materials.A rigorous,comparative,and critical analysis of preparation and testing methods is also presented.Electric power up to 14 mW was already achieved for the dry leaf/polyvinylidene fluoride-based TENG devices.These findings highlight the potential of eco-friendly self-powering systems and demonstrate the unique properties of the plants to generate electric energy for multiple applications.     

Resonator Rectenna Design Based on Metamaterials for Low-RF Energy Harvesting

In this paper, the design of a resonator rectenna, based on metamaterials and capable of harvesting radio-frequency energy at 2.45 GHz to power any low-power devices, is presented. The proposed design uses a simple and inexpensive circuit consisting of a microstrip patch antenna with a mushroom-like electromagnetic band gap (EBG), partially reflective surface (PRS) structure, rectifier circuit, voltage multiplier circuit, and 2.45 GHz Wi-Fi module. The mushroom-like EBG sheet was fabricated on an FR4 substrate surrounding the conventional patch antenna to suppress surface waves so as to enhance the antenna performance. Furthermore, the antenna performance was improved more by utilizing the slotted I-shaped structure as a superstrate called a PRS surface. The enhancement occurred via the reflection of the transmitted power. The proposed rectenna achieved a maximum directive gain of 11.62 dBi covering the industrial, scientific, and medical radio band of 2.40–2.48 GHz. A Wi-Fi 4231 access point transmitted signals in the 2.45 GHz band. The rectenna, located 45 anticlockwise relative to the access point, could achieve a maximum power of 0.53 μW. In this study, the rectenna was fully characterized and charged to low-power devices.     

A Review on Piezoelectric,Magnetostrictive, and Magnetoelectric Materials and Device Technologies for Energy Harvesting Applications

In the coming era of the internet of things (IoT), wireless sensor networks that monitor, detect, and gather data will play a crucial role in advancements in public safety, human healthcare, industrial automation, and energy management. Batteries are currently the power source of choice for operating wireless network devices due to their ease of installation; however, they require periodic replacement due to capacity limitations. Within the scope of the IoT, battery maintenance of the trillion sensor nodes that may be implemented will be practically infeasible from environmental, resource, and labor cost perspectives. In considering individual self‐powered sensor nodes, the idea of harvesting energy from ambient vibrations, heat, and electromagnetic waves has recently triggered noticeable research interest in the academic community. This paper gives an overview of energy harvesting materials and systems. Three main categories are presented: piezoelectric ceramics/polymers, magnetostrictive alloys, and magnetoelectric (ME) multiferroic composites. State‐of‐the‐art harvesting materials and structures are presented with a focus on characterization, fabrication, modeling and simulation, and durability and reliability. Some perspectives and challenges for the future development of energy harvesting materials are also highlighted.

     

应用于无线传感器节点的微小型复合能源收集系统(英文)

设计并实现了一种可应用于无线传感器节点的复合能源系统样机,基于一种无线地磁交通流传感器,提出了本文的设计目标.选择太阳能、风能、应变能作为系统的能量源.根据这3种不同能量源的特性,对能量管理模块与能量储存模块进行了针对性设计,最后实现并测试了样机.实验结果表明,该样机可连续35 h在3.55 V电压下输出50mW的电能.     

Scalable Bacterial Cellulose-Based Radiative Cooling Materials with Switchable Transparency for Thermal Management and Enhanced Solar Energy Harvesting

Radiative cooling materials that can dynamically control solar transmittance and emit thermal radiation into cold outer space are critical for smart thermal management and sustainable energy-efficient buildings. This work reports the judicious design and scalable fabrication of biosynthetic bacterial cellulose (BC)-based radiative cooling (Bio-RC) materials with switchable solar transmittance, which are developed by entangling silica microspheres with continuously secreted cellulose nanofibers during in situ cultivation. Theresulting film shows a high solar reflection (95.3%) that can be facilely switched between an opaque state and a transparent state upon wetting. Interestingly, the Bio-RC film exhibits a high mid-infrared emissivity (93.4%) and an average sub-ambient temperature drop of ≈3.7 °C at noon. When integrating with a commercially available semi-transparent solar cell, the switchable solar transmittance of Bio-RC film enables an enhancement of solar power conversion efficiency (opaque state: 0.92%, transparent state: 0.57%, bare solar cell: 0.33%). As a proof-of-concept illustration, an energy-efficient model house with its roof built with Bio-RC-integrated semi-transparent solar cell is demonstrated. This research can shine new light on the design and emerging applications of advanced radiative cooling materials.     

Hybrid Nanogenerators for Ocean Energy Harvesting: Mechanisms,Designs, and Applications

The ocean holds vast potential as a renewable energy source, but harnessing its power has been challenging due to low-frequency and high-amplitude stimulation. However, hybrid nanogenerators (HNGs) offer a promising solution to convert ocean energy into usable power efficiently. With their high sensitivity and flexible design, HNGs are ideal for low-frequency environments and remote ocean regions. Combining triboelectric nanogenerators (TENGs) with piezoelectric nanogenerators (PENGs) and electromagnetic nanogenerators (EMGs) creates a unique hybrid system that maximizes energy harvesting. Ultimately, hybrid energy-harvesting systems offer a sustainable and reliable solution for growing energy needs. This study provides an in-depth review of the latest research on ocean energy harvesting by hybrid systems, focusing on self-powered applications. The article also discusses primary hybrid designs for devices, powering self-powered units such as wireless communication systems, climate monitoring systems, and buoys as applications. The potential of HNGs is enormous, and with rapid advancements in research and fabrication, these systems are poised to revolutionize ocean energy harvesting. It outlines the pros and cons of HNGs and highlights the major challenges that must be overcome. Finally, future outlooks for hybrid energy harvesters are also discussed.     

Rational Design of MOF-Based Hybrid Nanomaterials for Directly Harvesting Electric Energy from Water Evaporation

The continuous exploration of clean-energy technology is critical for the sustainable development of society. The recent work on the electric energy harvesting from water evaporation has made a significant contribution to the utilization of clean energy for self-powering systems. Here, a novel metal–organic-framework-based hybrid nanomaterial is delicately designed and synthesized by the growth of UIO-66 nanoparticles on 2D AlOOH nanoflakes. Due to the combined merits from the 2D morphology, which is inherited from the AlOOH nanoflakes, and the high surface potential, which originates from the UIO-66 nanoparticles, the device made of the AlOOH/UIO-66 hybrid nanomaterials can harvest electric energy from natural water evaporation. An open-circuit voltage of 1.63 ± 0.10 V can be achieved on the prototype devices made of the hybrid nanomaterial. As a proof-of-concept application, a small electric appliance, e.g., a digital calculator, is powered up by a 3 × 3 device array connected in a combined series–parallel configuration.     

三角形状压电振子压电特性分析与仿真

(压电振子的几何形状是影响其振动发电的重要因素之一。在相同压电材料体积下,三角形压电振子相比于矩形和梯形压电振子具有更大的发电能力。选用悬臂梁式三角形状压电振子作为研究对象,利用有限元分析软件ANSYS进行仿真研究。建立有限元模型;通过静力学和模态分析,研究压电振子的几何形状对其输出电压、固有频率的影响规律,然后在满足原来输出电压不下降的前提下对其进行尺寸优化,提高单位体积的发电能力。在相同边界条件和外力作用下,优化尺寸模型的体积是原来的0.94倍,输出电压是原来的1.03倍,取得了很好的优化效果。