Energy Harvesting Devices Research Articles

Eco-friendly triboelectric nanogenerator for self-powering stacked In2O3 nanosheets/PPy nanoparticles-based NO2 gas sensor

As atmospheric issues and energy crises worsen, developing environmentally friendly, low-cost, high-performance self-powered gas sensing systems for gas pollutant monitoring is crucial for the development of ecological civilization. In this work, an eco-friendly self-powered nitrogen dioxide (NO2) sensor (EFNS) system based on an eco-friendly triboelectric nanogenerator (EF-TENG) is reported. The system comprises a power supply unit (EF-TENG) and a sensing unit (In2O3/PPy sensor), connected through a signal stabilization circuit. EF-TENG utilizes eco-friendly and biodegradable gelatin and PLA/PBAT as the friction layer. By introducing leaf structures on the gelatin surface using a template method, the output voltage and current of EF-TENG were increased by 1.44 and 1.67 times, respectively. The peak power density and root mean square power density of EF-TENG reached 1386 mW m−2 and 185.35 mW m−2, respectively. Additionally, EF-TENG exhibited excellent long-term stability, maintaining a stable output voltage (∼24 V) after rectification and voltage stabilization treatment under conditions of 15–55°C and 40–80 % RH. Additionally, an In2O3/PPy heterostructure sensor was prepared, and the EFNS system was constructed through impedance matching effects, revealing the NO2 response mechanism of the In2O3/PPy heterostructure. This achieved a wide detection range and highly sensitive (Vg/Va = 355 %@30 ppm) detection of NO2. This work provides insights into eco-friendly self-powered gas sensors and sensing mechanisms, offering ideas for the development of environmental monitoring sensors and clean energy harvesting devices.

Metal-organic framework based self-powered devices for human body energy harvesting.

The shift from traditional bulky electronics to smart wearable devices represents a crucial trend in technological advancement. In recent years, the focus has intensified on harnessing thermal and mechanical energy from human activities to power small wearable electronics. This vision has attracted considerable attention from researchers, with an emphasis on the development of suitable materials that can efficiently convert human body energy into usable electrical form. Metal-organic frameworks (MOFs), with their unique tunable structures, large surface areas, and high porosity, emerge as a promising material category for human body energy harvesting due to their ability to be precisely engineered at the molecular level, which allows for the optimization of their properties to suit specific energy harvesting needs. This article explores the progressive development of MOF materials, highlighting their potential in the realm of self-power devices for wearable applications. It first introduces the typical energy harvesting routes that are particularly suitable for harvesting human body energy, including thermoelectric, triboelectric, and piezoelectric techniques. Then, it delves into various research advances that have demonstrated the efficacy of MOFs in capturing and converting body-generated energy into electrical energy, emphasizing on the conceptual design, device fabrication, and applications in medical health monitoring, human-computer interaction, and motion monitoring. Furthermore, it discusses potential future directions for research in MOF-based self-powered devices and outlines perspectives that could drive breakthroughs in the efficiency and practicality of these devices.

A piezoelectric energy harvester for multi-type environments

Researchers have been studying the harvesting and utilization of mechanical vibration energy in the environment in recent years. Wind energy and water current energy are common energy in natural environment, the composite energy harvesting device that can harvest both wind energy and water energy is rarely reported. In this work, a piezoelectric energy harvester for multi-type environments is proposed, which can be installed in corresponding environments to harvest the wind energy, the water wave energy and the water current energy. In addition, the proposed energy harvesting device can adjust the attitude according to the direction of environmental energy. The energy harvesting principle is discussed and the performance of the device under different working conditions is tested by experiment. In the wind energy experiment, the maximum output power is 21.19 mW at a sustained wind speed of 8 m/s, and in the water energy experiment, the maximum output power is 2.01 mW at a medium infiltration depth and a flow velocity of 0.55 m/s. Finally, functional experiments are carried out to verify that the energy harvesting device proposed in this work can be put into practical use, and has a huge application prospect in long-term energy supply for outdoor microelectronic devices.

Physical and Chemical Surface Modification of Recycled Polystyrene Films for Improved Triboelectric Properties

Polystyrene (PS) is a very common material in packaging. In this study, it is recycled by turning it into energy harvesting devices: triboelectric generators. Herein, heat‐pressed films of recycled PS are formed and their surfaces are modified physically and chemically. The triboelectric properties of the films are determined using a dynamic testing machine, and the performance of the triboelectric generators is evaluated with a high‐speed contact–separation system. The developed charge density of the triboelectric generator increases two orders of magnitude—from 0.03 to 1.52 nC cm−2—by combining these surface modification methods. Such high values of charge density enable the production of single material triboelectric generators.

Engineered Lysozyme: An Eco‐Friendly Bio‐Mechanical Energy Harvester

Eco‐friendly and antimicrobial globular protein lysozyme is widely produced for several commercial applications. Interestingly, it can also be able to convert mechanical and thermal energy into electricity due to its piezo‐ and pyroelectric nature. Here, we demonstrate engineering of lysozyme into piezoelectric devices that can exploit the potential of lysozyme as environmentally friendly, biocompatible material for mechanical energy harvesting and sensorics, especially in micropowered electronic applications. Noteworthy that this flexible, shape adaptive devices made of crystalline lysozyme obtained from hen egg white exhibited a longitudinal piezoelectric charge coefficient (d ~ 2.7 pC N−1) and piezoelectric voltage coefficient (g ~ 76.24 mV m N−1) which are comparable to those of quartz (~2.3 pC N−1 and 50 mV m N−1). Simple finger tapping on bio‐organic energy harvester (BEH) made of lysozyme produced up to 350 mV peak‐to‐peak voltage, and a maximum instantaneous power output of 2.2 nW cm−2. We also demonstrated that the BEH could be used for self‐powered motion sensing for real‐time monitoring of different body functions. These results pave the way toward self‐powered, autonomous, environmental‐friendly bio‐organic devices for flexible energy harvesting, storage, and in wearable healthcare monitoring.

Integrating Battery-Less Energy Harvesting Devices in Multi-Hop Industrial Wireless Sensor Networks

Integrating Battery-Less Energy Harvesting Devices in Multi-Hop Industrial Wireless Sensor Networks

Novel ultrastable 2D MOF/MXene nanofluidic membrane with ultralow resistance for highly efficient osmotic power harvesting

Two-dimensional (2D) materials have shown great potential in harvesting osmotic power due to their high membrane selectivity, but the high resistance from tortuous pathways of 2D nanofluidic membranes still impedes the further improvement in output performance. Here, we report an innovative 2D MXCT (MXene/Cu-TCPP) lamellar membrane with ultralow resistance for highly efficient osmotic power generation. The incorporation of 2D Ti3C2Tx MXene with rich functional groups not only resolves the water-stability issue of 2D metal-organic framework (MOF) Cu-TCPP, but provides large surface charges for selective ion transport. The orderly sub-2 nm framework channels of Cu-TCPP provide much shorter permeation pathways for fast ion transport, thus endowing the MXCT membrane with ultralow resistance. Consequently, the MXCT membrane reaches an ultrahigh power output of ∼8.29 W/m2 by mixing seawater and river water, which is ∼275 % higher than that of the pristine MXene membrane. Additionally, it outperforms all the reported single-layer 2D nanosheet-based osmotic power generators under the same experimental conditions in terms of output power and internal resistance (9 kΩ). This work presents a reliable strategy for stabilizing 2D Cu-TCPP MOF in electrolytes, opening new avenues for designing promising 2D nanofluidic membranes for efficient blue energy harvesting and ionic devices.

Design and Experimental Research of a Lifting-Type Tidal Energy Capture Device

In this study, in order to promote the development of far-reaching marine aquaculture equipment in an intelligent direction and solve the problems related to power supply, a tidal current energy harvesting device for a low-velocity sea area is proposed. For low-velocity waters in farming areas, the device can effectively harness tidal energy to provide a stable power supply to open sea cages. A mathematical model of the Savonius turbine blade is established, and the influence of the distance between the impeller center and the water surface on the energy capture efficiency of the turbine is analyzed through numerical simulation. Using ANSYS2021R1 software, the velocity field of the floating body is simulated, and the overall structure and anchoring system of the power generation device is designed. In order to verify the effectiveness of the power generation device, a test model is built and a physical model test is carried out. The variation in parameters related to the relative distance between the impeller and the water under different flow velocities is tested, and the test data are analyzed. The test results show that the floating body can increase the flow speed by 10%. Optimizing the blade number and order of the S-turbine can capture more than 20% of the energy. Under different flow velocities, the capture power of the impeller first increases and then decreases with increasing distance from the water. When the center of the impeller is one-quarter of the impeller diameter higher than the water surface, the output power of the impeller is at the maximum. This indicates that the proposed power generation device can effectively use tidal energy under different water depth conditions and provide a stable power supply for far-reaching marine aquaculture equipment.

Spinel cobalt-based binary metal oxides as emerging materials for energy harvesting devices: synthesis, characterization and synchrotron radiation-enabled investigation.

The synthesis and characterization of spinel cobalt-based metal oxides (MCo2O4) with varying 3d-transition metal ions (Ni, Fe, Cu, and Zn) were explored using a hydrothermal process (140 °C for two hours) to be used as alternative counter electrodes for Pt-free dye-sensitized solar cells (DSSCs). Scanning electron microscopy (SEM) and atomic force microscopy (AFM) revealed distinct morphologies for each metal oxide, such as NiCo2O4 nanosheets, Cu Co2O4 nanoleaves, Fe Co2O4 diamond-like, and Zn Co2O4 hexagonal-like structures. The X-ray diffraction analysis confirmed the cubic spinel structure for the prepared MCo2O4 films. The functional groups of MCo2O4 materials were recognized in metal oxides throughout Fourier transform infrared (FTIR) analysis. The local structure analysis using X-ray absorption fine structure (XAFS) at Fe and Co K-edge identified octahedral (Oh) Co3+ and tetrahedral (Td) Co2+ coordination, with Zn2+ and Cu2+ favoring Td sites, while Ni3+ and Fe3+ preferred Oh active sites. Further investigations utilizing the Fourier transformation (FT) analysis showed comparable coordination numbers and interatomic distances ranked as Co-Cu > Co-Fe > Zn-Co > Co-Ni. Furthermore, the utilization of MCo2O4 thin films as counter electrodes in DSSC fabrication showed promising results. Notably, solar cells based on CuCo2O4 and ZnCo2O4 counter electrodes showed 1.9% and 1.13% power conversion efficiency, respectively. These findings indicate the potential of employing these binary metal oxides for efficient and cost-effective photovoltaic device production.

Piezoelectric Outputs of Electrospun PVDF Web as Full-Textile Sensor at Different Mechanical Excitation Frequencies.

With the increasing application of electrospun PVDF webs in piezoelectric sensors and energy-harvesting devices, it is crucial to understand their responses under complex mechanical excitations. However, the dependence of the piezoelectric effect on mechanical excitation properties is not fully comprehended. This study aims to investigate the piezoelectric output of randomly oriented electrospun PVDF nanofiber webs fabricated through different electrospinning processes at various mechanical excitation frequencies. The electrospun PVDF web was sandwiched between two textile electrodes, and its piezoelectric output as a full-textile sensor was measured across a frequency range from 0.1 Hz to 10 Hz. The experimental results revealed that the piezoelectric output of the electrospun PVDF web exhibited a nearly linear increase at excitation frequencies below 1.0 Hz and then reached an almost constant value thereafter up to 10 Hz, which is different from the hybrid PVDF or its copolymer web. Furthermore, the dependency of the piezoelectric output on the excitation frequency was found to be influenced by the specific electrospinning process employed, which determined the crystalline structure of electrospun PVDF nanofibers. These findings suggest that determining an appropriate working frequency for randomly oriented electrospun PVDF nanofiber webs is essential before practical implementation, and the piezoelectric response mode in different mechanical activation frequency ranges can be used to detect different human physiological behaviors.

Strong magnetoelectric coupling in novel Na0.5Bi0.5TiO3–BaFe12-2xCoxTixO19 multiferroic composite

Multiferroic composites of sol-gel synthesized Sodium Bismuth Titanate (Na0.5Bi0.5TiO3) and Co–Ti substituted Barium Hexaferrite (BaFe12-2xCoxTixO19; x = 0.0, 0.5, 1.0, 1.5 and 2.0) in the ratio 3:1 was synthesized through ceramic route. Successful formation of R3c rhombohedral and P63/mmc hexagonal phases corresponding to Na0.5Bi0.5TiO3 and BaFe12-2xCoxTixO19 respectively was confirmed from the XRD and Rietveld refinement pattern. The frequency and temperature dependence of dielectric constant and loss of the composite systems exhibited typical dispersion behaviour which could be understood using the Maxwell-Wagner model. Substituted samples showed enhanced dielectric behaviour where dielectric constant was observed to increase while loss tangent decreased. Using the Universal Jonscher's Power law (JPL), conductivition mechanisms of the composite systems were studied from the ac conductivity behaviour which revealed that the x = 0.0 sample followed Non-overlapping Small Polaron Tunnelling (NSPT) model while the remaining samples followed the Correlated Barrier Hopping (CBH) model. The complex impedance and Nyquist plot analysis showed the enhancement of resistive property in the x≠0 systems. Magnetic hysteresis loop measurements were conducted, and the associated parameters were determined with the assistance of the Law of Approach to Saturation (LAS). Favourable reduction in the magnetic anisotropy was observed indicating the disturbance of magnetic spin structure in the hexaferrite phase. The P-E loops established the novel room temperature multiferroic nature of the composite systems. Significant magnetoelectric coupling was detected at room temperature in all samples, with the x = 0.5 sample exhibiting the highest value of approximately 59.81 mV/cmOe. These desirable properties suggest that the composites may find future device applications as in magnetically tunable energy harvesting devices and self-powered magnetoelectric sensors in the future.

Performance Improvement and Application of Degradable Poly-l-lactide and Yttrium-Doped Zinc Oxide Hybrid Films for Energy Harvesting.

Piezoelectric nanogenerators (PENGs) are booming for energy collection and wearable energy supply as one of the next generations of green energy-harvesting devices. Balancing the output, safety, degradation, and cost is the key to solving the bottleneck of PENG application. In this regard, yttrium (Y)-doped zinc oxide (ZnO) (Y-ZnO) was synthesized and embedded into polylactide (PLLA) for developing degradable piezoelectric composite films with an enhanced energy-harvesting performance. The synthesized Y-ZnO exhibits high piezoelectric properties benefiting from the stronger polarity of the Y-O bond and regulation of oxygen vacancy concentration, which improve the output performance of the composite film with Y-ZnO and PLLA (Y-Z-PLLA). The obtained open-circuit voltage (Voc), short-circuit current (Isc), and instantaneous power density of the optimized Y-Z-PLLA PENG reach 17.52 V, 2.45 μA, and 1.76 μW/cm2, respectively. The proposed PENG also shows good degradability. In addition, practical applications of the proposed PENG were demonstrated by converting biomechanical energy, such as walking, running, and jumping, into electricity.

Analytical study of Restricted Access Window with short slots for fast and reliable data delivery from energy-harvesting sensors

To address the peculiarities of various Internet of Things applications and improve the performance of Wi-Fi-based sensor stations, a recent Wi-Fi HaLow standard introduces a mechanism called Periodic Restricted Access Window (PRAW). PRAW allows mapping groups of stations to periodic time intervals during which only these stations can transmit while the others cannot. This approach reduces contention and saves energy. However, the standard does not provide any recommendations on how to select the PRAW parameters according to scenario-specific requirements, leaving room for the research. A typical IoT scenario considers low-intensity traffic and requires fast and reliable data delivery from energy-harvesting devices while using the channel efficiently: there shall be still time for transmissions of other stations in the network. This paper develops an analytical model of PRAW that evaluates the probability of delivering data in time from every sensor station that harvests energy, accumulates it in small capacitors, and, thus, may not have enough energy for multiple retries. The model allows selecting such parameters of PRAW that minimize the channel resource consumption of a Wi-Fi HaLow network, provided that the delay and energy requirements are satisfied.

Przykłady Małej Architektury w oparciu o System Arm-Z

Arm-Z is a conceptual hyperredundant robotic manipulator composed on linearly joined number of identical modules. Each of them has one-degree-of-freedom (1-DOF) – the relative twist. Since modules are congruent, Arm-Z presents potential economical advantages and enhanced robustness. The modules can be mass produced and easily replaceable. The control of Arm-Z, however, is difficult and not intuitive. Therefore it most often requires the use of computational intelligence techniques. This article presents selected concepts for kinetic street furniture based on Arm-Z: a helical column of adjustable height, a sun tracking shade or solar energy harvesting device, bio-mimicing sculpture, sprinkler or fountain. All these ideas are based on low-tech approach. For this purpose, the initial unit in the chain is fixed to the solid foundation. For simplicity, the drive is applied directly to the first unit and transferred by the means of internal gears to the following modules. All of them are equipped with a set of cylindrical and bevel gears with straight teeth with involute profile (for connecting the modules).

Recent Progress in Polysaccharide-Based Materials for Energy Applications: A Review.

In recent years, polysaccharides have emerged as a promising alternative for the development of environmentally friendly materials. Polysaccharide-based materials have been mainly studied for applications in the food, packaging, and biomedical industries. However, many investigations report processing routes and treatments that enable the modification of the inherent properties of polysaccharides, making them useful as materials for energy applications. The control of the ionic and electronic conductivities of polysaccharide-based materials allows for the development of solid electrolytes and electrodes. The incorporation of conductive and semiconductive phases can modify the permittivities of polysaccharides, increasing their capacity for charge storage, making them useful as active surfaces of energy harvesting devices such as triboelectric nanogenerators. Polysaccharides are inexpensive and abundant and could be considered as a suitable option for the development and improvement of energy devices. This review provides an overview of the main research work related to the use of both common commercially available polysaccharides and local native polysaccharides, including starch, chitosan, carrageenan, ulvan, agar, and bacterial cellulose. Solid and gel electrolytes derived from polysaccharides show a wide range of ionic conductivities from 0.0173 × 10-3 to 80.9 × 10-3 S cm-1. Electrodes made from polysaccharides show good specific capacitances ranging from 8 to 753 F g-1 and current densities from 0.05 to 5 A g-1. Active surfaces based on polysaccharides show promising results with power densities ranging from 0.15 to 16 100 mW m-2. These investigations suggest that in the future polysaccharides could become suitable materials to replace some synthetic polymers used in the fabrication of energy storage devices, including batteries, supercapacitors, and energy harvesting devices.

Ferroelectric Material in Triboelectric Nanogenerator.

Ferroelectric materials, with their spontaneous electric polarization, are renewing research enthusiasm for their deployment in high-performance micro/nano energy harvesting devices such as triboelectric nanogenerators (TENGs). Here, the introduction of ferroelectric materials into the triboelectric interface not only significantly enhances the energy harvesting efficiency, but also drives TENGs into the era of intelligence and integration. The primary objective of the following paper is to tackle the newest innovations in TENGs based on ferroelectric materials. For this purpose, we begin with discussing the fundamental idea and then introduce the current progress with TENGs that are built on the base of ferroelectric materials. Various strategies, such as surface engineering, either in the micro or nano scale, are discussed, along with the environmental factors. Although our focus is on the enhancement of energy harvesting efficiency and output power density by utilizing ferroelectric materials, we also highlight their incorporation in self-powered electronics and sensing systems, where we analyze the most favorable and currently accessible options in attaining device intelligence and multifunctionality. Finally, we present a detailed outlook on TENGs that are based on ferroelectric materials.

A hybrid energy harvesting approach for transmission lines based on triboelectric nanogenerator and micro thermoelectric generator

To effectively detect faults in transmission lines, monitoring the operating status of these lines is imperative. However, providing power to monitoring devices for transmission line status presents a significant challenge. In this research, a hybrid energy harvesting approach based on micro thermoelectric generator (MTEG) and triboelectric nanogenerator (TENG) is proposed, and a theoretical model for MTEG-TENG hybrid energy harvesting is established. This study develops an integrated energy harvesting prototype, which incorporates oscillating-TENG (O-TENGs), MTEGs, and a power management control unit. This prototype not only harvests energy from the vibrations of transmission lines but also converts the lines thermal energy into electricity. The Experiment results show that the maximum open-circuit voltages of O-TENG and MTEG reach 80.3 V and 1.094 V, respectively. Compared to a single MTEG energy harvesting device, the prototype of the MTEG-TENG hybrid energy harvesting device demonstrates a 5.36% improvement in energy harvesting and battery charging performance. Consequently, this approach achieves self-powered monitoring with excellent stability and lower manufacturing costs. It provides an efficient and durable power approach for transmission line status monitoring devices.

Lead-Free Compositional Engineering to Induce Polar Phase in Polymeric Piezoelectric Host for Energy Harvesting Devices

Lead-Free Compositional Engineering to Induce Polar Phase in Polymeric Piezoelectric Host for Energy Harvesting Devices

Developments and prospects of additive manufacturing for thermoelectric materials and technologies

In view of the increased demand for electricity and the associated environmental and financial concerns, there is an urgent need to develop technological solutions that can improve the efficiency of engineering systems and processes. Thermoelectric (TE) technologies, with their capability of direct conversion of thermal energy into electrical energy, are promising technologies for green power generation through using them as energy harvesting devices for waste heat recovery in industrial processes and power generation systems.To date, TE technologies are still not commercialized on a large scale due to various economic and technical obstacles. The majority of previous research on TE technologies concentrated on improving the TE properties, such as electronic transport and figure-of-merit, while limited attempts were made to identify the best material processing techniques or reduce the cost of manufacturing. Conventional Manufacturing (CM) of TE materials and devices is multi-stage, complex, labour-intensive, time-consuming, and has high energy requirements. Thus, manufacturing challenges are considered key contributors toward limited industrial adoption of TE technologies.The rapid advent of advanced Additive Manufacturing (AM) processes, in recent years, caused dramatic changes in engineering design thinking and created opportunities to solve manufacturing challenges. With its significant capabilities, AM can be the route to address the shortcomings of CM of the thermoelectric technologies. In this regard, this paper presents an in-depth review of the literature studies on using AM technologies, such as selective laser melting, fused deposition modelling, direct ink writing, stereo lithography, etc., for manufacturing TE materials and devices. The benefits and challenges of each AM technology are discussed to identify their merits and the required future research. This paper demonstrates the role of AM in advancing green materials and technologies for solving some of the outstanding energy and environmental issues.

Spinning the Future: The Convergence of Nanofiber Technologies and Yarn Fabrication.

The rapid advancement in nanofiber technologies has revolutionized the domain of yarn materials, marking a significant leap in textile technology. This review dissects the nexus between cutting-edge nanofiber technologies and yarn manufacturing, aiming to illuminate the pathway toward engineering advanced textiles with unparalleled functionality. It first discusses the fundamentals of nanofiber assemblies and spinning techniques, primarily focusing on electrospinning, centrifugal spinning, and blow spinning. Additionally, the study delves into integrating nanofiber spinning technologies with traditional and modern yarn fabrication principles, elucidating the design principles that underlie the creation of yarns incorporating nanofibers. Twisting technologies are explored to examine how they can be optimized and adapted for incorporating nanofibers, thus enabling the production of innovative nanofiber-based yarns. Special attention is given to scalable strategies like centrifugal and blow spinning, which are spotlighted for their efficiency and scalability in fabricating nanofiber yarns. This review further analyses recently developed nanofiber yarn applications, including wearable sensors, biomedical devices, moisture management textiles, and energy harvesting and storage devices. We finally present a forward-looking perspective to address unresolved issues in nanofiber-based yarn technologies.