Improved Energy Harvesting Research Articles

The effect of magnetic proof masses on the energy harvesting bandwidth of piezoelectric coupled cantilever array

In order to explore the ability of magnetic force in improving energy harvesting bandwidth, a novel energy harvester of piezoelectric coupled cantilever array (PCCA) was proposed which introduces nonlinear magnetic force (damping) to differentiate the natural frequencies of PCCs and widen energy harvesting bandwidth of PCCA. Meanwhile, the design of PCCA can increase the number of voltage peaks of each PCC at the cost of decreasing the voltage peaks of its neighbouring PCCs at resonance. The effect of some significant factors, such as PCC interval, PCS length, PCC number, and PCC substrate thickness, on PCC voltage, PCC natural frequency, and PCCA bandwidth are deeply studied and analyzed by experiments and simulations. The results demonstrate that the bandwidth for the proposed PCCA can achieve 73 Hz by the standard of >15 V pp. voltage in the excitation of 1 g acceleration amplitude. Based on the experiment and simulation results, a series of theoretical models are derived to compute PCC voltage, PCC natural frequency, and bandwidth of PCCA with different design parameters, these theoretical models give a reliable instruction for the design of PCCAs to match environmental vibration with different frequency such as machine, wind, wave, and so on.

Collecting the energy of the electromagnetic fields over the infrared band based on the metastructures

Predicated on the surface plasmon polariton, this study proposes the metastructures (MSs) constructed from copper and general dielectric films. The MSs are specifically designed to gather electromagnetic (EM) wave energy over the infrared band on the surface. Evidence illustrates that, when EM waves impinge the surface of the MSs, there is a significant surge in surface energy density, confirmed to be a staggering 2022.90 times higher than that of the ancillary EM waves. This substantial multiplication owes its genesis to the enhanced impedance matching between the MSs and free space. Furthermore, the MSs demonstrate the ability to accurately determine refractive indices ranging from 1 to 1.39, as well as measure hydrogen density spanning from 0 g/cm3 to 0.13 g/cm3. This is achieved through the assessment of absorption peak locations, the intensity of absorption, and the field enhancement factor (FEF) at the peak. The subtle absorption peak experiences a shift in alignment with the changes in refractive indices. The relationship between the peak position and the refractive index demonstrates an exceptional degree of linearity, achieving the R2 value of 1. The values of Q, Sλc, and FOM average at 1437, 1.24 μm·RIU−1, and 682.38 RIU−1, respectively. The study also examines the effects of the incident angle of the external electromagnetic (EM) field and the number of dielectric films. Within a limited range of incident angles, an increase in the angle results in a shift of the absorption peak towards shorter wavelengths. The number of films plays a role in modifying the absorption intensity and the field enhancement factor (FEF) at the peaks. The proposed MSs offer improved energy harvesting capabilities from the surface EM fields. They can also be employed for refractive index detection. Besides, the field enhancement phenomenon provides valuable insights into the adsorption and storage of the hydrogen.

Sustainable Energy Harvesting Mechanism with Flow-Induced Vibration

This study investigates the feasibility of utilizing a flow-induced vibration actuator as a potential energy source using piezoelectric energy harvesting. The focus is on exploring the behavior of piezo films configured as cantilever beams subjected to flow-induced vibration, which can be induced with fluid or wind streams. The primary objective is to maximize the harvested energy from the vibrating structure. This paper develops theoretical models to analyze the resonant frequencies and energy-harvesting potential of the piezo films in the context of flow-induced vibration. Experimental validations are conducted to verify the theoretical predictions. The findings indicate that higher operating frequencies in the second mode offer improved energy harvesting efficiency compared with lower modes. With the strategic adjustment of resonant frequencies using attached masses on individual piezo films, the harvestable energy output of a single film can be significantly increased from less than 1 μW to approximately 18 μW. However, the phase differences among individual piezo films can impact frequency measurements, necessitating careful fine-tuning of the physical conditions of individual components. To optimize energy harvesting, this study emphasizes the importance of implementing efficient charging mechanisms. By identifying suitable environmental vibration sources, the required charging duration for a synthesized energy harvesting array can be reduced by 25% as well. Despite certain challenges, such as phase deviations and turbulence, this study demonstrates the promising potential of flow-induced vibration resonators as sustainable energy sources. This work lays the foundation for further advancements in energy harvesting technology, offering environmentally friendly and renewable energy solutions.

Coupled responses of the flow-induced vibration and flow-induced rotation of a rigid cylinder-plate body

In this study, coupled responses of flow-induced vibration and rotation for an elastically mounted cylinder-plate body are numerically investigated at a low Reynolds number of 120. A wide vibrational reduced velocity range of Uy = 3–18 under four rotational reduced velocities Uθ = 5, 8, 12, and 18 are considered. The non-bifurcation responses, bifurcation only in rotation responses, and bifurcation in both vibration and rotation responses are identified. Typical vortex-induced vibration (VIV) responses are recognized when considering the passive rotations, different from the full interactions between VIV and galloping for the vibration-only case. As Uθ increases, the peak vibration amplitudes increase, the onset Uy of the lock-in region becomes larger, and the lock-in region is wider. The phase angles of displacements versus lift coefficients experience a jump from 0° to 180° in the lock-in region, and the larger the Uθ, the wider the Uy range of phase jump. Whether the instantaneous posture of the cylinder-plate body is streamlined or not is determined by oscillation amplitudes and phase differences between displacements versus rotation angles. Streamlined profiles can be achieved under small oscillation amplitudes or when the phase angles are nearly 90°. The 2S (two isolated vortices) vortex shedding mode dominates the initial and desynchronization branch, while the 2P (two pairs of vortices), 2S* (two isolated vortices with tendency to split), and 2T (two triplets of vortices) modes appear in the lock-in region. After the symmetry-breaking bifurcation, the reattachment behavior becomes simpler and the length of the recirculation region is significantly increased, as compared with those in non-bifurcation region. With the above study, a new method of improving energy harvesting from flow-induced vibration, by incorporating passive rotations simultaneously, is first introduced. It is found that passive rotations can enhance the vibration responses and thus lead to the increased output power and energy transfer ratio, although they make less contributions to the total power. Generally, this mechanical system presents a promising opportunity for energy harvesting through flow-induced vibration.

Coral-like BaTiO3-Filled Polymeric Composites as Piezoelectric Nanogenerators for Movement Sensing.

Piezoelectric nanogenerators have prospective uses for generating mechanical energy and powering electronic devices due to their high output and flexible behavior. In this research, the synthesis of the three-dimensional coral-like BaTiO3 (CBT) and its filling into a polyvinylidene fluoride (PVDF) matrix to obtain composites with excellent energy harvesting properties are reported. The CBT-based PENG has a 163 V voltage and a 16.7 µA current at a frequency of 4 Hz with 50 N compression. Simulations show that the high local stresses in the CBT coral branch structure are the main reason for the improved performance. The piezoelectric nanogenerator showed good durability at 5000 cycles, and 50 commercial light-emitting diodes were turned on. The piezoelectric nanogenerator generates a voltage of 4.68-12 V to capture the energy generated by the ball falling from different heights and a voltage of ≈0.55 V to capture the mechanical energy of the ball's movement as it passes. This study suggests a CBT-based piezoelectric nanogenerator for potential use in piezoelectric sensors that has dramatically improved energy harvesting characteristics.

Towards a luminescent solar concentrator with ultra-broadband absorption and spectral conversion for optimizing photovoltaic solar cell response: “The photonic cannon shot”

Solar energy harvesting is largely limited by the spectral sensitivity of the employed photovoltaic solar cell, since typically the full potential of each photon of the whole solar spectrum is not efficiently used in the generation of electricity. Therefore, increasing the overall solar spectrum utilization is of crucial interest and stands up as a frontier-of-research approach in the photovoltaic sector. Here we present an innovative ultra-broadband absorption and multiple spectral conversion approach, by means of rare-earth doped materials together with organic dyes embedded in a luminescent solar concentrator. The combination of different luminescent materials is a key factor for improving energy harvesting over the whole solar spectrum. At the same time, a simultaneously combined effect of up-conversion and down-shifting of light is aimed to optimal spectral matching with amorphous silicon solar cells response. Thus, UV–visible photons coming from the incoming sunlight, together with UV–visible up-converted photons coming from near-infrared radiation, can be all shifted to the yellow-orange-red part of the spectrum. To the best of our knowledge, this represents the first reported proof-of-concept using LSCs with up-conversion and down-shifting photonic processes working together and sequentially.

Improving energy harvesting from low-frequency excitations by a hybrid tri-stable piezoelectric energy harvester

This paper presents the design of a novel hybrid tri-stable piezoelectric energy harvester (HTPEH) that improves the energy harvesting efficiency of piezoelectric energy harvesters operating at low frequencies. The proposed HTPEH is an extension of a conventional tri-stable cantilever piezoelectric energy harvester with an elastic base (TPEH + EB), and it incorporates vertical and rotational elastic amplifiers that are installed between the mass block at the left end of a cantilever beam and the left side of a U-shaped frame to enhance the system's nonlinear characteristics. By utilizing Hamilton's principle, a HTPEH's nonlinear electromechanical equation is formulated, and the harmonic balance method is used to obtain analytical solutions for the displacement amplitude, voltage amplitude, and power amplitude. The study investigates the effects of various parameters, including the elastic amplifier-to-base stiffness ratio and elastic amplifier-to-piezoelectric cantilever beam mass ratio on the energy harvesting performance of the HTPEH. The results indicate that the displacement and voltage amplitude of the HTPEH exhibit two peaks as the external excitation frequency increases, and adjusting the relative mass and stiffness between the elastic amplifier and the piezoelectric cantilever beam can alter the frequency band interval where the two response peaks of the system are located. This allows the HTPEH to enter inter-well motion at low-level external excitation, resulting in high output power. The HTPEH outperforms the TPEH + EB in terms of energy harvesting efficiency under low-frequency environmental excitation.

Numerical investigation of variable damping model based on cylinders with different submergence depths

To reduce the blockage effect, a novel arrangement involving a submerged cylinder and a floating cylinder arranged in tandem is studied using two-dimensional RANS equations in conjunction with the SST k-ω turbulence model. The motion of the cylinders is solved using the Newmark-β method. A variable damping method based on movement velocity is proposed to achieve continuity of motion and improve energy harvesting. Results indicate that the variable damping method enhances the motion response, increasing amplitude by 20.832% (submerged cylinder) and 34.764% (floating cylinder). Moreover, the absorbed power of the floating cylinder increases by 9%. Powers and exponent are comparatively linear concerning each other based on energy harvesting: absorbed power increases with increasing exponent when the exponent is smaller than 1, while it decreases with increasing exponent when the exponent is bigger than 1.

Systematic investigation of the effect of SnS2 nanofiller content on the piezoelectric performance of the PVDF-TrFE-based nanogenerator

In this work, SnS2 is used as a nanofiller material to improve the response of the polymer-based piezoelectric nanogenerator because of its better inherent piezoelectric properties in comparison to other 2D materials. For this, first, nanoflakes of tin sulfide (SnS2) were synthesized via the hydrothermal method, where the high purity of SnS2 powder is confirmed by Raman spectroscopy and X-ray diffraction studies. The obtained powder of SnS2 was then mixed with PVDF-TrFE in different weight percentages (0%, 1%, 3%, 5%, and 7%) of SnS2 to synthesize polymer composite films via drop-casting method. These films are then characterized with XRD and FTIR spectrometers which show enhancement in the electroactive beta phase of the nanocomposite films after doping of SnS2 powder, from 58.30% to 93.07%, which is in agreement with the polarization versus electric field (P-E) measurements that show increased remnant polarization after doping. These films are then used to fabricate a piezoelectric nanogenerator by adhering aluminum tape on both sides of the films. The piezoelectric nanogenerator's (PENG) output performance is analyzed by measuring the open-circuit voltage (Voc) and short-circuit (Isc) by tapping the nanogenerator with the help of a dynamic shaker, which shows that the output performance of PVDF-TrFE based PENGs gets enhanced after the introduction of SnS2 powder. The maximum output voltage of 14.4 V is obtained corresponding to the PENG with 5 wt% SnS2, which was almost 1.5 times that of the PENG made with bare PVDF-TrFE. The output piezoelectric current follows the similar trend, with the 5 wt% SnS2 PENG producing3.9μA of current, which was roughly 1.62 times more than the output of the bare PVDF-TrFE thin film. As a result, the present study demonstrates that adding SnS2 to the PVDF matrix can significantly improve energy harvesting technologies based on PVDF's piezoelectric properties.

Janus Metal–Organic Framework Membranes Boosting the Osmotic Energy Harvesting

The unique ion-transport properties in nanoconfined pores enable nanofluidic devices with great potential in harvesting osmotic energy. The energy conversion performance could be significantly improved by the precise regulation of the "permeability-selectivity" trade-off and the ion concentration polarization effect. Here, we take the advantage of electrodeposition technique to fabricate a Janus metal-organic framework (J-MOF) membrane that possesses rapid ion-transport capability and impeccable ion selectivity. The asymmetric structure and asymmetric surface charge distribution of the J-MOF device can suppress the ion concentration polarization effect and enhance the ion charge separation, exhibiting an improved energy harvesting performance. An output power density of 3.44 W/m2 has been achieved with the J-MOF membrane at a 1000-fold concentration gradient. This work provides a new strategy for fabricating high-performance energy-harvesting devices.

Effect of geometric non-linearity and tip mass on the frequency bandwidth of a cantilever piezoelectric energy harvester under tip excitation

The research community is investigating a variety of approaches to convert mechanical energies to useful electrical energy in order to fulfil the ever-increasing demand for energy and fulfil the requirements of the various sectors. In this regard, numerous contributions toward increasing the capacity and efficiency of the various energy harvesting techniques have been proposed in recent times; one such promising technology is piezoelectric-based vibration energy harvesting. In the present work, the effect of geometric nonlinearity and tip mass is investigated on the operational frequency range of a cantilever nonlinear piezoelectric energy harvester. The proposed mathematical model is based on an energy-based variational approach. The methodology is formulated for the piezoelectric patched cantilever beam and, eventually solved using an efficient numerical technique . An amplitude incremental iterative algorithm is used to solve the non-linear governing equations of motion for the proposed non-linear broadband harvester along with the experimental validation. Firstly, a parametric study is performed to determine the optimum piezoelectric patch dimensions. Subsequently, the attempt is made to increase the frequency bandwidth for optimum energy harvesting by taking advantage of geometrically non-linear behaviour. Additionally, a tip mass, appropriate for the excitation level, can be added to the harvester design to make it effective for lower excitation frequency. Increased frequency bandwidth for improved energy harvesting capacity with the hardening type nonlinearity and tip mass is meaningfully shown with the help of frequency-amplitude response. Furthermore, to interpret the efficacy of nonlinear harvesters in terms of frequency band-width, power spectral density plots with improved harvesting capability are presented and compared with the conventional linear vibration energy harvester.

Nature-Driven Biocompatible Epidermal Electronic Skin for Real-Time Wireless Monitoring of Human Physiological Signals.

Wearable bioelectronic patches are creating a transformative effect in the health care industry for human physiological signal monitoring. However, the use of such patches is restricted due to the unavailability of a proper power source. Ideal biodevices should be thin, soft, robust, energy-efficient, and biocompatible. Here, we report development of a flexible, lightweight, and biocompatible electronic skin-cum-portable power source for wearable bioelectronics by using a processed chicken feather fiber. The device is fabricated with a novel, breathable composite of biowaste chicken feather and organic poly(vinylidene fluoride) (PVDF) polymer, where the chicken feather fiber constitutes the "microbones" of the PVDF, enhancing its piezoelectric phase content, biocompatibility, and crystallinity. Thanks to its outstanding pressure sensitivity, the fabricated electronic skin is used for the monitoring of different human physiological signals such as body motion, finger and joint bending, throat activities, and pulse rate with excellent sensitivity. A wireless system is developed to remotely receive the different physiological signals as captured by the electronic skin. We also explore the capabilities of the device as a power source for other small electronics. The piezoelectric energy harvesting device can harvest a maximum output voltage of ∼28 V and an area power density of 1.4 μW·cm-2 from the human finger imparting. The improved energy harvesting property of the device is related to the induced higher fraction of the electroactive phase in the composite. The easy process ability, natural biocompatibility, superior piezoelectric performance, high pressure sensitivity, and alignment toward wireless transmission of the captured data make the device a promising candidate for wearable bioelectronic patches and power sources.

Improved energy harvesting ability of C3H7NH3PbI3 decorated PVDF nanofiber based flexible nanogenerator

Propylammonium lead iodide, C3H7NH3PbI3, was synthesized by sol-gel method and incorporated in polyvinylidene difluoride (PVDF) to produce nanofibers by electrospinning technique. These nanofibers possess an improved degree of crystallinity with the successful conversion of non-polar phase to polar phase content. The tensile strength and thermal stability of nanofibers are also enhanced significantly with the addition of C3H7NH3PbI3. The fabricated lightweight, flexible, durable, cost-effective, self-powered piezoelectric nanogenerator is observed to generate 60 V open circuit voltage, 27.5 μA short circuit current, and 9.81 mW/m2 power under periodic hammering with a free hand. Voltage generation of this nanogenerator scavenging mechanical energy from various sources is also detected. This device exhibits remarkable mechano-sensitivity (∼ 6.3 V/N in the low applied force region and 12.12 V/N in the higher applied force region) with superior energy conversion efficiency ∼ 42.03 %. The flexibility along with ultra-sensitivity of this power generator initiates its utility as wearable nano sensors. Moreover, the ultrafast capacitor charging ability of the nanogenerator assures its potential as a nano-tactile sensor. The optimal energy band gap and photoactive nature of the C3H7NH3PbI3@PVDF composite confirm its efficacy as a photodetector/diode. Therefore, the proposed C3H7NH3PbI3@PVDF composite enables to design a multifaceted device that can perform separately/simultaneously as mechanical energy and solar energy harvester.

Efficacy of singly curved thin piezo transducers for structural health monitoring and energy harvesting for RC structures

Piezoelectric materials have secured a significant place in the field of structural health monitoring (SHM) and energy harvesting over the past two decades. These materials are available in several forms and configurations, the efficacy of especially curved configurations is still unexplored. This article investigates, both experimentally and numerically, the potency of the curved configuration of the piezo transducers over the straight configuration when embedded in reinforced concrete (RC) structures for energy harvesting and SHM. The study consists of the comparative analysis of (a) open-circuit voltage generated across the piezo transducers; (b) the power developed under the impedance matching conditions; and (c) the potential of power storage into capacitors for both configurations. The article also experimentally examines the hitherto unexplored damage detection capability of the curved piezo transducers by the electro-mechanical impedance (EMI) technique. Results clearly demonstrate that curved piezo transducers exhibit better performance in comparison to straight configurations for both structural health monitoring and energy harvesting. A finite element (FE) analysis is also performed through a 3-D model of the real-life-sized RC beam with straight and curved piezo transducers embedded inside to evaluate the various parameters such as the angle of bend, the thickness, the number of elements and the position of placement of the curved transducers for energy harvesting. The FE simulations reveal an optimum range of the angle of bend as 130 to 160 degrees. There is a substantial impact of the increase in thickness of the transducers for energy harvesting in terms of its open-circuit voltage. The numerical analysis also suggests that the optimum position of placement of the piezo transducers is towards the top or bottom of the beam cross-section. The outcomes of the experimental and numerical investigations are very pivotal for the implementation of curved piezo transducers in real-life RC structures for improved energy harvesting and structural health monitoring.

An experimental application on energy harvesting with piezoelectric on asphalt pavements

With the dramatic increase in the world population, the demand for transportation and, accordingly, energy is also increasing. Clean and renewable energy sources are one of the most important research topics in all countries. The word piezo-electric that, means energy from pressure, is the ability of the material to change an electric field or electric potential as a result of mechanical pressure applied to some materials. This effect is directly related to the change in polarization density inside the material. If the material is not short-circuited, the applied loading and stress creates a voltage in the material. Energy production with materials that provide piezoelectric energy harvesting placed within asphalt pavements is one of the topics that road pavement engineers have been researching in recent years. This study was carried out as a preliminary study. In this study, experiments were made using different sensors to improve energy harvesting from asphalt pavements. The difference of this study from other studies was that different piezoelectric sensors were placed in the asphalt mixture samples and the measurements of the resulting voltages were made. As a result of the experimental study, voltages up to 0.210 V were obtained in the asphalt samples. The obtained results showed that this method is encouraging for energy harvesting and might be the answer for highway transport demand in the future.

Control of Cascaded Multilevel Converter for Wave Energy Applications

This paper proposes a control scheme for a wave energy conversion system based on a linear generator and a cascaded multilevel converter. The mechanical conversion system is composed of a buoy connected directly to a linear generator. The windings of the generator are individually controlled by a cascaded multilevel power converter using independent maximum power point tracking to improve energy harvesting. The output of the cascaded converter is controlled to keep the DC capacitors balanced and generate a multilevel voltage at the output terminals which reduces the losses in the underwater transmission line. Experimental results show the performance of the proposed control scheme maximizing the power generation by imposing a current with the same waveform of the induced voltage and balancing the DC capacitors.

Improving energy harvesting by nonlinear dual-beam energy harvester with an annular potential energy function

In this paper, we develop a nonlinear dual-beam energy harvester for broadband energy harvesting. Two identical piezoelectric cantilevers are placed orthogonal to each other and coupled by repulsive magnetic force. Analytical and experimental studies indicate that the combination of the resonant motions of the two beams yields an annular potential energy function, where the oscillator can circumambulate around the potential barrier. The advantages of the design concerning a conventional bistable piezoelectric cantilever were examined. It is proved that the proposed harvester has a bandwidth of 3.4 Hz and a voltage output performance 298.7% better than that of a bistable one under excitations of 0.5 g.

Dramatically enhanced energy harvesting capability in sandwich-structure modulated piezoelectric nanocomposites

Piezoelectric energy harvesting devices (PEHs) offer great potential for diverse electronic applications. However, it is still a great challenge to well combine appropriate mechanical strength and high output performance in composite-type PEHs. Herein, the sandwich-structured composite-type PEHs for high-output mechanical energy harvesting using piezoelectric Barium titanate nanoparticles and poly(vinylidenefluoride-co-trifluoroethylene) (P(VDF-TrFE)) copolymers matrix is reported. By intentionally modulating the distribution of piezoelectric nanoparticles in polymer matrix, a highest output of ∼60 V (open-circuit voltage), and ∼65 μW/cm3 (power density at load resistance of 50 MΩ), respectively, was obtained. Via mechanical property and energy harvesting capability quantification, the dramatically improved energy harvesting capability is determined to be stemmed from the stress-enforcement in embedded piezoelectric nanoparticles and optimized piezoelectric response. Besides, the device presents a sufficient mechanical durability, which endows it the ability for long time stable operation. This work sheds light on a universal strategy for fabricating high-performance composite-type PEHs by constructing a gradient distribution of piezoelectric active nanoparticles in polymer matrix.

Anion-Dependent Polarization and Piezoelectric Power Generation in Hybrid Halide MAPbX3 (X = I, Br, and Cl) Thin Films with Out-of-Plane Structural Adjustments.

Anion-dependent differences in the electromechanical energy harvesting capability of perovskite halides have not been experimentally demonstrated thus far. Herein, anion-dependent piezoelectricity and bending-driven power generation in high-quality methylammonium lead halide MAPbX3 (X = I, Br, and Cl) thin films are explored; additionally, anisotropic in situ strain is imposed to improve energy harvesting under tensile bending. After applying the maximum in situ strain of -0.73% for all the halide thin films, the MAPbI3 thin-film harvester exhibited a peak voltage/current of ≈23.1V/≈1703 nA as the best values, whereas MAPbBr3 and MAPbCl3 demonstrated ≈5.6V/≈176 nA and ≈3.3V/≈141 nA, respectively, under identical bending conditions. Apart from apparent ferroelectricity of tetragonal MAPbI3 , origin of the piezoelectricity in both cubic MAPbBr3 and MAPbCl3 is explored as being related to organic-inorganic hydrogen bonding, lattice distortion, and ionic migration, with experimental supports of effective piezoelectric coefficient and grain boundary potential. Conclusively, piezoelectricity of the cubic halides is assumed to be due to their soft polarity modes and relatively low elastic modulus with vacancies contributing to space-charge polarization. In the case of ferroelectric MAPbI3 , the distortion of PbI6 octahedra and atomic displacement within each octahedron are quantitatively estimated.

Natural Superhydrophobic Surfaces and Application

Superhydrophobicity refers to the phenomenon that the contact angle of various low surface tension water droplets on the solid surface is greater than 150°. Over the past few years, people have paid more attentions in the superhydrophobic surfaces’ design and application. The superhydrophobic surfaces are meaningful for basic research and various practical applications, such as self-cleaning, drag reduction, lubrication, and more. This paper summarizes the recent advances and developments in superhydrophobic surfaces systematically. Furthermore, in this work, the authors focus on the basic concepts of superhydrophobic surfaces and commonly used synthetic methods. Electrodeposition and electrospinning methods are mainly introduced. Finally, we also discuss the limitations and challenges encountered in the study of superhydrophobicity, mainly with regard to the fact that drag should be reduced to improve energy harvesting efficiency.