Multilayered flexible nanocomposite for hybrid nano- generator enabled by conjunction of piezoelectricity and triboelectricity

We fabricate a flexible hybrid nanogenerator （HNG）, based on multilayered nanocomposite materials, which integrates a piezoelectric nanogenerator （PENG） and a triboelectric nanogenerator （TENG） into a single structure with only two electrodes. The HNG enables enhancement of the electrical output of the nano- generators. An open-circuit voltage of 280 V and a short-circuit current of 25 μA are achieved by a HNG of 2.5 cm × 2.5 cm in size, superior to the performance of previously reported HNGs. In addition, the energy-conversion process of the HNG relies on the working mechanism of both the PENG and TENG. The polarization direction and doping content of BTO are the two major factors that affect the electrical output. Biomechanical energy harvesting from walking motion or the bending of an arm is also demonstrated.

Whirligig‑Inspired Hybrid Nanogenerator for Multi‑strategy Energy Harvesting

Portable energy solutions are highly desired in the era of the Internet of Things for powering various distributed micro-electronic devices.At the same time,the energy crisis and catastrophic global warming are becoming serious problems in the world,emphasizing the urgent need for clean and renewable energy.Here,we report a low-cost,high-performance,and portable hand-driven whirligig structured triboelectric–electromagnetic hybrid nanogenerator(whirligig-HNG)for multi-strategy energy harvesting.The whirligig-HNG comprises a dynamic supercoiling TENG via the pulling-strings and inner-distributed EMGs(variable number)in the rotator.The whirligig structure can readily convert linear displacement in low frequency into rotary motion in extremely high frequency.Based on this ingenious design,the whirligig-HNG is capable to harvest the triboelectric energy from the supercoiling/uncoiling process from the pulling strings and simultaneously utilize the high-frequency rotation energy via electromagnetic induction.We have systematically investigated the working mecha-nism of the whirligig-HNG for coupled energy harvesting and compared the individual characteristics of TENG and EMG.The whirligig-HNG is successfully demonstrated to light up more than 100 commercial light-emitting diodes(LEDs)and drive portable electronics.This research presents the enormous potential of whirligig-HNG as a manual and portable power supply for powering various portable electronics.

A Hybrid Biofuel and Triboelectric Nanogenerator for Bioenergy Harvesting

Various types of energy exist everywhere around us,and these energies can be harvested from multiple sources to power micro-/nanoelectronic system and even personal electronic products.In this work,we proposed a hybrid energy-harvesting system(HEHS)for potential in vivo applications.The HEHS consisted of a triboelectric nanogenerator and a glucose fuel cell for simultaneously harvesting biomechanical energy and biochemical energy in simulated body fluid.These two energy-harvesting units can work individually as a single power source or work simultaneously as an integrated system.This design strengthened the flexibility of harvesting multiple energies and enhanced corresponding electric output.Compared with any individual device,the integrated HEHS outputs a superimposed current and has a faster charging rate.Using the harvested energy,HEHS can power a calculator or a green light-emitting diode pattern.Considering the widely existed biomechanical energy and glucose molecules in the body,the developed HEHS can be a promising candidate for building in vivo self-powered healthcare monitoring system.

Hybridized triboelectric-electromagnetic nanogenerators and solar cell for energy harvesting and wireless power transmission

Energy harvesting and power transmission is a significant challenge for the self-powered technologies towards mobile electronic devices.Here,we propose a hybridized energy harvester to complement each other's strengths for simultaneously scavenging multiple types of energy and then wirelessly transmit the power.The harvester consists of electromagnetic-triboelectric nanogenerator units for collecting rotational energy and a commercial water-proof flexible solar cell.At a rotation rate of 500 rpm,the output current of electromagnetic-triboelectric nanogenerator units can reach about 630 mA through energy management.Moreover,the power harvested by hybridized energy harvester can be wirelessly transmitted up to a distance of about 100 cm in real time to charge mobile phone,anemometer,and hygrometer based on self-resonant coils.The hybridized energy harvester with wireless power transmission has potential applications in large-scale energy collection,long-distance wireless power transmission and sustainably driving mobile electronic devices.

Solar cell-based hybrid energy harvesters towards sustainability

Energy harvesting plays a crucial role in modern society.In the past years,solar energy,owing to its renewable,green,and infinite attributes,has attracted increasing attention across a broad range of applications from small-scale wearable electronics to large-scale energy powering.However,the utility of solar cells in providing a stable power supply for vari-ous electrical appliances in practical applications is restricted by weather conditions.To address this issue,researchers have made many efforts to integrate solar cells with other types of energy harvesters,thus developing hybrid energy har-vesters(HEHs),which can harvest energy from the ambient environment via different working mechanisms.In this re-view,four categories of energy harvesters including solar cells,triboelectric nanogenerators(TENGs),piezoelectric nanogenerators(PENGs),and thermoelectric generators(TEGs)are introduced.In addition,we systematically summar-ize the recent progress in solar cell-based hybrid energy harvesters(SCHEHs)with a focus on their structure designs and the corresponding applications.Three hybridization designs through unique combinations of TENG,PENG,and TEG with solar cells are elaborated in detail.Finally,the main challenges and perspectives for the future development of SCHEHs are discussed.

雨滴能量收集型摩擦纳米发电机的研究进展

简单阐述了摩擦纳米发电机(TENG)的工作原理及4种基本工作模式。总结了雨滴能量收集型TENG在基于垂直接触-分离结构、单电极结构、独立层结构3种工作模式及多种基本工作模式集成的结构优化及应用。介绍了开发出的其他结构类型的TENG及通过表面处理、结构优化等方式对雨滴能量收集效率的增强。此外,对其他类型如太阳能、风能等清洁能源收集装置与雨滴能量收集型TENG集成为互补的混合能源装置进行了介绍和分析。最后,对目前TENG在雨滴能量收集方面存在的问题和不足进行总结,并展望了未来的挑战和发展方向。

面向智能家居的混合能量收集系统研究

针对当前智能家居环境中分布的大量传感器节点供电难的问题,提出一种基于摩擦纳米发电机和电磁发电机的混合能量收集系统,可有效将智能家居环境中人体运动产生的机械能转换为电能输出。实验证明,该系统具有良好的输出性能,与所设计的电源管理电路相结合可以为智能家居中分布的传感器节点稳定供电。该系统的提出为解决智能家居中传感器节点的供电问题提供了一种新方案。

非谐振式的电磁-摩擦复合式纳米发电机

针对人体机械能频率低(<10 Hz)、振幅高、运动不规则的特点,为了实现对人体机械能的高效采集,本文利用非线性频带拓宽技术的单稳态法设计了一款非谐振式摩擦-电磁复合式能量采集器。该器件将电磁发电机(Electromagnetic Nanogenerator,EMG)和摩擦纳米发电机(Triboelectric Nanogenerator,TENG)集成至一个具有非线性特性的磁悬浮系统中,利用非线性系统幅频曲线共振峰值偏移现象,拓宽了器件的频率响应范围;引入了柔性多层摩擦发电单元,不仅增强了器件的低频响应特性,还提高了器件的输出功率。测试结果表明:在6 Hz、10 m/s^(2)的振动条件下,当外接电阻为100 MΩ,顶部摩擦发电单元TENG1和底部摩擦单元TENG2的瞬时输出功率分别为202.5μW和348.1μW;当外接电阻为60Ω时,两组电磁发电单元EMG1和EMG2的瞬时输出功率均可达到150 mW。此外,设计的复合式能量采集器不仅可以通过人体在4 min内的运动将容值0.022 F的电容器从0 V充电到3.3 V,还可以驱动低功耗传感器。所设计能量采集器突破了传统谐振式能量采集器在低频、随机振动环境下能量采集效率低的难题,能够用于自供电式低功耗便携式电子产品。

面向智能轴承自供电系统的压电-摩擦复合式振动能量采集器

针对智能轴承外圈径向开槽结构中以电池供能的状态监测设备存在应用场合受限的问题,提出了一种适用于智能轴承自供电系统的压电-摩擦复合式振动能量采集器。该能量采集器以带双质量块的三角形单晶压电悬臂梁为基础,在悬臂梁的振动方向上有机集成兼具限位功能的摩擦纳米发电机,实现了振动和限位碰撞过程中压电-摩擦电两种模式的复合协同发电,有效利用了空间并提高了输出性能。同时,利用集中参数法建立了能量采集器的机电耦合动力学模型,通过COMSOL软件分析了不同结构与尺寸对压电悬臂梁固有频率和输出电压的影响,并通过试验验证机电耦合动力学模型与仿真分析的准确性。试验结果表明:所提能量采集器能够在0~28.2 m/s^(2)的智能轴承正常工作振动加速度范围内有效工作;在加速度为2 m/s^(2)时,该采集器的压电和摩擦电单元开路输出电压最大峰峰值分别可达1.28 V和1.05 V;在加速度为20 m/s^(2)时,该采集器的压电和摩擦电单元开路输出电压最大峰峰值分别可达2.85 V和1.18 V。

Low-frequency wide-band hybrid energy harvester based on piezoelectric and triboelectric mechanism

Recently,hybrid energy harvester has been considered as an attractive potential approach to response the worldwide energy crisis due to the combination of advantages from different harvesting mechanism.In this paper,a novel low-frequency wide-band hybrid energy harvester based on piezoelectric and triboelectric mechanism is presented and systematically studied including structural design,fabrication process,working principle simulation and measurement.With a vibrational excitation,the polyvinylidene fluoride(PVDF) cantilevers will vibrate and impact the polydimethylsiloxane(PDMS) film on the substrate,producing a piezoelectric output as well as a triboelectric output.The structural parameters of each cantilever are optimized using finite element simulation,and the well-designed PVDF cantilevers with controllable PDMS mass not only reduce the device working frequency but also enlarge the bandwidth.Under a sweep-frequency test,three voltage peaks induced by the piezoelectric part are observed at 15,32.5 and 47.5 Hz,with the value of 320,288 and 264 mV,respectively.With the combined triboelectric part,a 20 V peak-peak voltage is generated at 15 Hz.The electrical driving ability of this hybrid energy harvester also has been demonstrated by lighting up a commercial light emitting diode(LED).

纳米发电机的研究现状及发展趋势

综述了纳米发电机的技术发展状况,系统介绍了纳米发电机的分类及工作原理,阐述了不同种类纳米发电机的特点和适用范围。基于国内外关于纳米发电机的研究,重点分析了纳米发电机的发电特性,对比了不同种类纳米发电机的开路电压、电流密度及功率密度的大小。最后,讨论了目前纳米发电机存在的问题,并且针对这些问题以及不同纳米发电机的特点和研究现状,对纳米发电机的发展趋势进行了预测,指出未来应着眼于高性能材料、工作原理和仿真模型、纳米发电机的集成化以及能量收集电路等方面的研究,并继续优化发电机结构,改进制备工艺以提高发电机性能。

一体式柔性可拉伸拱形摩擦-压电复合纳米发电机

针对目前可穿戴单兵能源装备对能源采集器件柔性可拉伸能力的迫切需求,提出了一种基于摩擦-压电协同换能机理的一体式柔性可拉伸拱形纳米发电机设计方案。利用混炼工艺将钛酸钡(BaTiO3)、聚四氟乙烯(PTFE)和镀银玻璃微珠分别混入到高温硫化硅橡胶中,分别制备出压电层、摩擦层和电极层,使器件实现了全柔性和可拉伸性能。器件采用拱形结构,可以响应拉伸和拍打两种常见的激励模式,有助于高效采集具有多自由度特点的人体运动能量。实验结果表明,拉伸模式下,器件主要依靠压电层产生电能输出,而在拍打模式下,器件则主要依靠摩擦层产生电能输出,复合输出性能得到明显提升,展现出其在可穿戴单兵能源装备领域广阔的应用前景。

复合微能源采集器研究进展及其应用

微能源采集技术是一门新兴的能源技术,受到国内外学者的广泛关注.近年来,随着电子产品功耗的逐步降低,采集环境能源为这些电子产品供电是解决目前电池供电持久性差、环境污染等难题的最佳方式.根据其工作原理的不同采集器可分为电磁式发电机、压电纳米发电机、摩擦纳米发电机等几类.单一换能机制的器件受制于其转换效率,无法实现对能量的最大转换.复合式发电机通过不同换能方式的一体化高度集成,实现对输出性能的提升,具有良好的应用前景.本文综述了近年来不同类型复合式发电机的研究现状,阐述了其工作原理及实际应用,对研究复合式微能源采集器具有一定参考价值.

振动能量收集技术的研究现状与展望

气候变暖、海平面上升、冰川消融等自然环境变化对人类社会的发展构成巨大挑战,迫使人们加速绿色能源技术的开发。微纳米技术、机械与材料工程的迅速发展使得振动能量的收集与应用成为可能,其主要部分为通过电磁转换、静电转换、压电转换、磁致伸缩转换、磁电转换、摩擦纳米发电以及它们的复合形式将振动能量转化为电能。其中摩擦纳米发电是最新的研究热点之一。本文回顾了振动能量收集技术原理、材料、结构等方面的研究现状,重点综述了国内外学者的主要研究成果,详细阐述了多种收集方式的原理、特点和电学输出性能,总结了目前该技术存在的关乎耦合性能、频带、收集效率、集成性和寿命等有待进一步解决的关键问题,并由此展望振动能量收集技术的研究发展趋势,希望为集能设计研究领域的工作者提供有价值的参考。

柔性纳米发电机及器件的最新研究进展

伴随着经济和社会的进步,人们对智能化、微型化、便携式电子设备的需求越来越迫切,推动了智能可穿戴器件和微电子系统的发展。供电系统是现代电子设备重要的组成部分,传统电池存在续航短、污染重等缺点。因此,亟待寻求一种绿色可持续供电的微电子器件。相比于传统纳米发电机,柔性纳米发电机以其优异的柔韧性、机械性和易加工性成为当前的研究热点,为解决目前可穿戴电子设备的供电需求问题提供了重要方法和路径。其中,柔性压电式、摩擦电式等自供电模式纳米发电机近年来受到广泛的应用和关注。综述了压电式、摩擦电式和复合式纳米发电机的国内外研究进展和工作原理,阐述了基于不同材料、结构和应用领域的纳米发电机,并对其在复合器件中的应用进行了概述,对该领域的发展趋势进行了总结和展望。

基于Ti_(3)SiC_(2)/Ecoflex纳米复合材料的足底能量采集器

由于人体运动幅度以及频率往往毫无规律,且运动频率很低,这使人体运动能量难以有效采集。针对此问题,研制了一种可高效收集低频能量的足底能量采集器。Ti_(3)SiC_(2)/Ecoflex作为足底能量采集器的负性摩擦材料,经过掺杂和表面修饰后足底能量采集器的电学性能提升了107%。足底能量采集器在2 Hz的运动频率下输出功率可达1.66 mW,面功率密度为1.84 W/m^(2)。此外,在工作10 h后电学性能保持不变,具有优异的稳定性与耐久性。实验表明,当人处于行走或者奔跑状态时,足底能量采集器可以分别为50盏LED灯以及温湿度计供能。这进一步推动了摩擦纳米发电机在人体运动能量采集领域的广泛应用。

基于拱形结构的摩擦-压电复合式能量采集器

随着纳米技术和加工工艺的发展,纳米发电机被提出用于将自然界中微弱低频振动机械能转化为电能,进而为小型传感系统长续航工作提供可能。基于摩擦纳米发电机和压电纳米发电机的电荷积累与转移规律,设计了拱形结构并构建了摩擦-压电复合式能量采集器,将两种力-电转换模式有效整合,并突破了以往能量采集器只能收集垂直方向机械能的限制。搭建了测试系统,研究了能量采集器的输出性能。摩擦单元经过整流后的输出开路电压和输出短路电流分别可达60 V和1.25μA,压电单元经过整流后的输出开路电压和输出短路电流分别为约10 V和约0.9μA。此外,制备的能量采集器不仅可为电容进行充电,还可点亮50只发光二极管(LED),在驱动小型电气设备领域展现出应用潜力。

Recent progress on flexible nanogenerators toward self-powered systems

The advances in wearable/flexible electronics have triggered tremendous demands for flexible power sources,where flexible nanogenerators,capable of converting mechanical energy into electricity,demonstrate its great potential.Here,recent progress on flexible nanogenerators for mechanical energy harvesting toward self-powered systems,including flexible piezoelectric and triboelectric nanogenerator,is reviewed.The emphasis is mainly on the basic working principle,the newly developed materials and structural design as well as associated typical applications for energy harvesting,sensing,and selfpowered systems.In addition,the progress of flexible hybrid nanogenerator in terms of its applications is also highlighted.Finally,the challenges and future perspectives toward flexible self-powered systems are reviewed.

Magnetically levitated/piezoelectric/triboelectric hybrid generator as a power supply for the temperature sensor

The combination of new intelligent materials and structure technology is becoming an effective way in energy havesting and self-powered sensing. In this work, we demonstrate a magnetically levitated/piezoelectric/triboelectric hybrid generator, which does not use complex structure and has high steady output performance. It includes three parts: magnetically levitated generator(MLG), piezoelectric generator(PNG), triboelectric nanogenerator(TENG). The peak power of each is 135 μW, 22 mW and3.6 mW, which are obtained at 1 MΩ, 10 kΩ and 1 kΩ, respectively. The hybrid generator can completely light up light-emitting diodes(LEDs) under the vibration frequency of 20 Hz and the vibration amplitude of 10 mm. It also can charge a 470 μF capacitor.On this basis, we have integrated the hybrid generaor as a power supply into a self-powered tempreature sensing system. The combination of three generators can not only broaden the operating range, but also increase the operating length and sensitivity.This work will extend the application of self-powered sensor in automatic production line and promote the development of industrial control technology.

PVDF/SBS柔性复合纤维薄膜压电-摩擦电纳米发电机

可将无规则机械能转换为电能的压电纳米发电机与摩擦纳米发电机能够为低功耗可穿戴电子设备提供独立、持续性供电,有利于促进柔性自供能电子器件多元化的发展。将二者进行集成,可综合二者电输出特性的优点,提高纳米发电机的性能。本文分别以聚偏二氟乙烯(PVDF)与苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)为正、负极摩擦材料,采用静电纺丝方法制备了PVDF/SBS复合纤维薄膜,并利用该复合纤维薄膜得到压电-摩擦电复合纳米发电机。研究结果表明:当PVDF掺入量为20wt%时,PVDF/SBS复合纤维薄膜的电学输出性能最佳,器件的开路电压与短路电流最大可达108 V与0.34μA,分别是纯SBS样品的5倍与6倍。将器件固定在手掌、鞋底处,收集拍手、行走、跑步等运动的能量,可产生不同幅度的输出电压,表明器件可有效收集人体运动的机械能;通过手掌拍打器件,可点亮64只商用蓝色LED灯珠;同时器件可检测瞬时压力变化,灵敏度最大可达3.685 V·N^(-1)。上述结果表明PVDF/SBS柔性复合纤维薄膜压电-摩擦电纳米发电机在传感监测和电子器件自供能领域具有良好的应用前景。