Broad Frequency Range Research Articles

Dynamics of ionic liquid-polymer gel membranes-Insight from NMR relaxometry for [BMIM][BF4]-PVDF-HFP systems.

1H spin-lattice relaxation experiments have been performed for ionic liquid-polymer gel membranes, including 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF4]) and poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP) with different proportions. The experiments have been performed in a broad range of resonance frequencies (from about 5Hz to 40MHz) vs temperature and complemented with analogous studies for [BMIM][BF4] in bulk as a reference. A model of the relaxation processes in the membranes has been proposed. The model includes two relaxation contributions. One of them corresponds to the concept of restricted, two-dimensional translation diffusion with a residence lifetime, while the second one has the form characteristic of polymers (mathematically similar to the limiting behavior of two-dimensional translation diffusion with a very long residence lifetime). The extensive dataset has been consistently interpreted in terms of the model, revealing two dynamical processes on the time scales of 10-7s (for the second relaxation contribution) and 10-9s (for the first one). The relationship of these relaxation contributions to the motion of the polymer or ionic liquid-polymer complexes and to the translation diffusion of BMIM cations in the matrix has been discussed.

Joint Wideband Spectrum Sensing and Carrier Frequency Estimation in the Multi-Path Propagation Environment Based on Sub-Nyquist Sampling

We consider the wideband spectrum sensing within a multi-path propagation environment, where a multi-antenna base station (BS) is tasked with identifying the frequency positions of multiple narrowband transmissions distributed across a broad range of frequencies. To tackle this, we propose a sub-Nyquist sampling structure that incorporates a phased array system. Specifically, each antenna is connected to two separate sampling channels, i.e., one for direct sampling and another for delayed sampling, with the latter incorporating a specified time delay factor. The cross-correlation matrices associated with the samples, which are characterized by different time lags, are calculated. These matrices are represented in tensor form, and the factor matrices are extracted through CANDECOMP/PARAFAC (CP) decomposition. By these factor matrices, the carrier frequencies and the power spectra of the far-field signals of interest are estimated. Numerical simulations are conducted to evaluate the performance of the proposed method, and the results reveal the feasibility and effectiveness of the approach, demonstrating its potential for accurate and efficient wideband spectrum sensing in complex multi-path propagation environments.

Reconfigurable wide-angle broadband terahertz wave antireflection using a non-volatile phase-change material.

Actively wide-angle broadband terahertz (THz) antireflection (AR) coatings with a flexible reconfigurability have a great potential for the development of next-generation versatile THz components and systems with high performance. Here, we present a reconfigurable wide-angle broadband THz AR coating using a phase change material Ge2Sb2Te5 (GST) film, which is based on the impedance matching method. The performance of GST-based AR coating can be effectively achieved by a thermal excitation, exhibiting the complete suppression of unwanted THz-wave reflections for incidence angles from 0∘ to 50∘ in the broad frequency range of 0.1-3.0 THz. Simulation and experimental results show that the GST-based AR coating can efficiently eliminate Fabry-Perot interference caused by unwanted THz-wave reflections from the substrate, thereby significantly improving the performances of THz devices. Moreover, the active AR mechanism of the GST-based coating is investigated, which elucidates the essential role of the phase transition between the amorphous and crystalline phases in changing the conductivity of the film to achieve an impedance matching condition under thermal excitation. Additionally, the non-volatile properties of GST can enable the AR coating to retain a long-term stability for optimal wave-impedance matching without power holding requirements. Our work provides a new, to the best of our knowledge, and promising way for realizing high-performance integrated THz components and systems in the future.

Key Sputtering Parameters for Precursor In2O3 Films to Achieve High Carrier Mobility.

Owing to their extremely high carrier mobility (μ) of >100 cm2/(V s) and suitable low carrier concentrations, transparent conducting films of solid-phase crystallized H-doped In2O3 (spc-IO:H) exhibit high conductivity with high optical transparency over a broad frequency range. These properties can be attributed to solid-phase crystallization of the amorphous precursor film. Therefore, the development of high-quality spc-IO:H films requires the deposition conditions of the precursor films to be optimized. This study systematically investigates the effects of three key sputtering parameters, namely, water vapor partial pressure (PH2O), radio frequency magnetron sputtering power (PRF), and flow ratio of O2 to total sputter gas (fO2) on the crystallographic texture evolution of spc-IO:H films during solid-phase crystallization. In addition, the carrier transport in the resulting films is examined. PH2O, PRF, and fO2 are found to be indispensable for producing high-mobility (>100 cm2/(V s)) spc-IO:H films. Furthermore, it is found that introducing a small amount of PH2O during deposition, a lower PRF, and a suitable fO2 facilitates the formation of precursor films having a lower crystallite density. Moreover, after annealing at a temperature of 200 °C, the IO:H precursor films with a lower crystallite density are found to have larger crystal grains. However, the μ values of the postannealed IO:H films are mainly correlated with the stoichiometric deviation.

Development of Flexible Hydrophobic Polypropylene/SPCB/GNP Hybrid Nanocomposite Films With Excellent EMI Shielding and Mechanical Properties

ABSTRACTThe demand for effective electromagnetic interference (EMI) shielding materials has driven the development of novel and facile approach for fabrication of conductive polymer nanocomposites. In this study, a polypropylene (PP)‐based hybrid nanocomposite was prepared by incorporating Super P conductive carbon black (SPCB) and graphene nanoplatelets (GNP) via latex technology. A simplistic method of fabrication was adopted where the nanofillers were stirred into the PP latex at room temperature, ensuring the proper dispersion of fillers within the matrix. Hybridizing the nanocomposite by the usage of two different fillers has resulted in a substantial improvement in EMI shielding performance of the material along with its mechanical and thermal properties. The samples were fabricated and tested in three different thicknesses to ensure that EMI shielding effectiveness (EMI SE) is a thickness dependent property and also the studies were carried out over a broad range of microwave frequency. A high electrical conductivity of 7.6 S m−1 was obtained and exceptional EMI SE of 65 dB (X band), 69.76 dB (Ku band), and 72.38 dB (K band) was showcased by 2 mm thickness composites. The optical images of PP latex incorporated with the fillers gave a clear understanding about the formation of conducting networks within the polymer matrix at percolation threshold. The addition of SPCB and GNP also showed a significant increase in hardness and tensile strength of the composite and helped in protecting the polymer matrix against photo radiation. The fillers also aided in the enhancement of the hydrophobicity of the films. The thermal stability, crystallization temperature (TC) and melting temperature (TM) of the composites were also improved when compared to that of neat The works aims at fabricating a hydrophobic and low‐density polymer nanocomposite showing excellent absorption dominant EMI SE.

A frequency-independent absorption function surrogate for perfectly matched layer in exterior acoustics

In many engineering applications, the solution of acoustic wave problems in the infinite domain is required over a broad frequency range with densely sampled increments. In order to achieve efficient numerical simulations via a spatial discretization, e.g. finite element method, additional artificial absorbing boundaries are necessary to truncate the computational domain into appropriate bounded sizes. One of the most commonly used non-reflecting techniques to attenuate propagating waves is known as the perfectly matched layer. However, the system matrices arising from the finite element treatment of the Helmholtz equation in the absorbing layers are frequency-dependent, implying that they must be formed and inverted at each frequency of interest. Such a procedure is rather troublesome for frequency sweeps. To address this, a surrogate of perfectly matched layers is proposed, which enables the corresponding system matrices to be independent of the frequency. Moreover, it avoids the use of a relatively large computational domain and relatively thick enclosed layers at low frequencies, thus improving the ability of perfectly matched layers across the entire frequency range. After that, an adaptive projection-based model order reduction scheme is further developed to reduce the computational complexity of exterior acoustic systems. A robust error indicator based on the relative error of two constructed reduced order models is accordingly introduced. The performance of the present solution framework is discussed and compared with other implementation strategies, in the context of multi-frequency solution of two-dimensional test models with single or multiple scatterers.

SH guided wave excitation in rails for defect and stress monitoring

Monitoring rail defects and thermal stress is imperative in ensuring the safety of railway transportation. Guided-wave-based inspection techniques emerge as a promising solution for concurrently detecting both the defects and thermal stress in rails. However, the substantial multimodal and dispersive nature of guided waves in the rail poses limitations on the application and advancement of this technology. This study systematically investigates the propagation characteristics of the SH0-like wave (the lowest-order shear horizontal-like wave) in the rail and its effectiveness in defect and axial stress monitoring through finite element simulations and experiments. A method based on dual opposite polarization active elements, and the corresponding piezoelectric transducers are proposed to excite SH0-like wave in the rail web and rail foot. Results show that SH0-like wave can travel stably across a broad frequency range in the rail web and rail foot. Additionally, both the simulations and experiments confirm that the SH0-like wave in the rail web is suitable for monitoring axial stress, as its velocity changes linearly with axial stress variations. Furthermore, the ability of the SH0-like wave to detect cracks and hole defects in the rail web is experimentally demonstrated. Given that the SH0-like wave is quasi-nondispersive in a broad frequency range and an SH0-like wave with high SRN can be effectively generated using the proposed method, this research aims to offer a practical technical solution to overcome the challenges of multimodal and dispersive effects in the guided-wave-based rail inspection techniques. It also sets the stage for developing a comprehensive system capable of simultaneously monitoring the defects and thermal stress in rails.

Single layer vanadium oxide assisted switchable metasurfaces for transmissive and reflective polarization conversion

Polarization control using metasurfaces is highly advantageous; however, most metasurfaces operate exclusively in either transmission or reflection mode. Additionally, achieving both wide bandwidth and high efficiency simultaneously in their design remains a significant challenge. Here, we design a high-efficiency and wideband switchable metasurface that can switch between transmissive and reflective polarization conversion modes by utilizing a single layer of I-shaped resonators and gold-vanadium dioxide (VO2) alternating gratings printed on a quartz substrate. When VO2 transitions to its metallic phase, the continuous metal layers of gold-VO2 eliminate transmission and the designed metasurface operates as a reflective cross-polarization converter with a polarization conversion ratio (PCR) exceeding 0.9 over a broad frequency range of 1.4–3.3 THz. Conversely, when VO2 is in its insulator phase, the THz incoming wave can transmit through the gratings, and the design behaves as a transmissive cross-polarization converter with a PCR above 0.99 in the 0.75-4.0 THz range for a forward y- polarized wave. The working mechanism for both transmissive and reflective polarization conversion modes is explained through theoretical analysis and surface current distributions. With the advantages of facile design, high performance, and dual functionality, our design is expected to be applied in the fields of imaging, sensing, and communication.

Enhanced SiC/NFG/Ni ternary composite microwave absorbing materials with micro-network structures produced by selective laser sintering

In this paper, a ternary composite wave-absorbing material consisting of silicon carbide (SiC), natural flake graphite (NFG) and nickel (Ni) has been successfully fabricated through a combined process of selective laser sintering (SLS) and vacuum pressure impregnation. The study investigated how the content of SiC powder affected the absorption capacity and mechanical performances of the composites. The findings indicate that as the proportion of SiC powder rises, the porosity of the composites diminishes, while the bending strength increases. As the content of SiC is 40 wt%, the porosity is 52.14 % and the flexure strength is 9.58 MPa, approximately five times greater than that of graphite-type ceramic preforms. The composite’s electromagnetic wave-absorbing capability initially improves and then declines with the increase of SiC content. When the SiC content is 10 wt% and the thickness is 1.5 mm, the composite absorbing material exhibits optimal electromagnetic absorption performance, with a minimum reflection loss (RLmin)of −44.04 dB and an effective absorption bandwidth (EAB) of 5.42 GHz (8.24–13.66 GHz). The composite material, characterized by its lightweight, high strength, and broad frequency range, shows promise for applications in microwave absorption technology.

A Universal Plug-and-Play Approach to In Situ Multinuclear Magnetic Resonance Analysis of Electrochemical Phenomena in Commercial Battery Cells.

Advancing electrochemical energy storage devices relies on versatile analytical tools capable of revealing the molecular mechanisms behind the function and degradation of battery materials in situ. The nuclear magnetic resonance phenomenon plays a pivotal role in fundamental studies of energy materials and devices because of its exceptional sensitivity to local environments and the dynamics of many electrochemically relevant elements. The jelly roll architecture is one of the most energy-dense and, therefore, most popular concepts implemented in pouch, prismatic, and cylindrical Li- and Na-ion cells. Such widely commercialized designs, however, represent a significant obstacle for a range of powerful in situ magnetic resonance-based methodologies due to negligible radio frequency electromagnetic field penetration through conductive metal casings and current collectors. In this work, we introduce an experimental setup that enables direct RF wave transmission through the cell terminals and current collectors, and provides efficient excitation and detection of NMR signals. An RF adapter designed as a plug-and-play device effectively turns the battery cell into an NMR probe that can be tuned to a broad range of Larmor frequencies. Due to its exceptional sensitivity, versatility, and multinuclear capability, the proposed methodology is suitable for fundamental research and industrial high-throughput screening applications. In situ NMR lineshapes provide a direct quantitative description of the chemical environments of electrochemically active elements and enable new metrics for the accurate assessment of state-of-charge (SoC) and state-of-health (SoH). Specifically, in commercial pouch cells based on lithium cobalt oxide, lithium nickel manganese cobalt oxide, and sodium nickel iron manganese oxide chemistries, 7Li and 23Na NMR data unambiguously show electrochemical transformations between intercalated and metallic forms of charge carrier ions, and reveal anisotropic magnetic properties of the electrode coating.

Search for thermonuclear burst oscillations in the Swift/BAT data set

This study comprehensively analyzes type I X-ray bursts observed by Swift/BAT from 2005 to April 2024 to search for X-ray burst oscillations (XBOs) in neutron star low-mass X-ray binaries. XBOs, periodic signals detected within type I X-ray bursts, typically range from 11 to 620 Hz and are often observed in the soft X-ray data of these bursts. Using the high-sensitivity and precise timing capabilities of the Swift/BAT, we found 50 type I X-ray bursts from 37 neutron star low-mass X-ray binaries. We conducted a detailed timing analysis of these bursts. For sources with known burst oscillation frequencies, our findings largely corroborate previous studies. However, many sources displayed low confidence levels in the oscillation signals, with Z12 values between 10 and 20. For sources without known oscillation/spin frequencies, we utilized FFT analysis to search for signals across a broad frequency range. This approach revealed potential oscillation signals, with several bursts showing significance levels exceeding 3σ, including those from MAXI J1421–613, XTE J1701–407, XMM J174457–2850.3, Swift J1734.5–3027, IGR J17473–2721, Swift J174805.3–244637, Swift J181723.1–164300, and X 1832–330.

Using wave based SEA methods to model noise and vibration in underwater structures across a broad frequency range

Modelling noise and vibration transmission in underwater structures is often challenging due to the large size of the structures and the need for analysis across a broad frequency range. Finite Element and Boundary Element methods are useful at lower frequencies but are typically not computationally tractable for system level models at mid and high frequencies. Statistical Energy Analysis (SEA) methods are widely used for modeling structures in air at mid and high frequencies. However, traditional SEA methods often do not contain enough detail to describe wave propagation in heavy fluid loaded structures in underwater applications. This paper discusses the use of a more general 'wave based' SEA method that uses periodic structure theory to accurately calculate the wavetypes of typical underwater structures. The paper illustrates the method by initially considering simple structural sections and showing the effects of: curvature, heavy fluid-loading, panel stiffeners/ribs. The method is then applied to a simplified full scale submarine model and comparisons are made with a nodal finite element model. The domain of validity and the hypotheses of the method are then discussed.

Low-frequency broadband acoustic ventilation meta-barrier based on consecutive multiple Fano resonances

Acoustic metamaterials utilizing Fano resonance provide the possibility of simultaneous airborne sound insulation and high-performance ventilation. However, the ultra-sharp line shape results in a narrow working frequency range, which is still insufficient for practical applications. In this work, we propose a low-frequency acoustic meta-barrier supporting consecutive multiple Fano resonances (CMFRs) with broadband (~75%) capability, efficient ventilation, and ultra-thin thickness, etc. The barrier features a binary metastructure, incorporating a chiral space coiling tunnel and a hollow pipe in a planar arrangement. This configuration offers discrete and continuous states within the composed Fano system, corresponding to the tunnel and the pipe, respectively. By means of superposition of multi-order Fano resonance modes, the destructive interference between the discrete and continuum states keeps effective in a broad frequency range, while simultaneously achieving high air permeability. Numerical results of transmission loss show significant attenuation of incident energy in the range of 479-1032 Hz. Our work lays the groundwork for next generation of Fano-based metamaterial applications, with far-reaching implications for noise control and related fields.

Design and analysis of Conceptual acoustic metamaterials applied to mitigating cooling fan noise for heavy-duty vehicles

The noise generated from cooling fans in heavy-duty vehicles like trucks poses challenges regarding environmental pollution and overall user comfort. To solve this problem, this study develops an acoustic metamaterial (AMM) that is constructed with small Helmholtz resonators in two layers. This concept can attenuate the noise in a broad frequency range. Furthermore, the particle swarm optimization (PSO) algorithm based on artificial intelligence (AI) is used to optimize the AMM structure. The key design parameters are discussed and analyzed. The installation strategies are put forth to examine the performance of the AMM. The proposed metamaterials, combined with the installation strategies, are numerically simulated using the finite element method. The results show that the current AMM is effective in reducing both tonal and broadband noise of interest. The findings shed light on the development of acoustic metamaterials for cooling-fan noise reduction in heavy-duty vehicles.

Effects of sound on bluff body aerodynamic characteristics in separated and reattaching flows

The coupling effects between sound and flow on the aerodynamic characteristics of bluff bodies are commonly encountered in engineering practices, such as wind turbine blades and heat exchanger compressors. This study experimentally investigates the effects of sound over a broad range of frequencies (0–400 Hz) and sound pressure levels (80–105 dB) on the streamwise wind pressures on a flat plate in both smooth and turbulent flows. Spectral analysis and proper orthogonal decomposition (POD) are employed to explore the effects of sound on the aerodynamic forces acting on the flat plate. The results show that the effects of sound on wind pressure distributions and separation bubble behaviors over the flat plate depend on both sound frequency and sound pressure level. Furthermore, the findings highlight the role of acoustic resonance, which can increase the fluctuating wind pressure on the plate surface by over 400%. These effects can also be influenced by sound pressure levels. Additionally, the results demonstrate varying degrees and forms of attenuation of sound effects in turbulent flows, depending on the wind flow characteristics.

Ultra‐wide Band Antipodal Vivaldi Antenna Using Metasurface Lens for Gain and Front‐To‐Back Ratio (FBR) Improvement

AbstractThis paper addresses the limited gain of conventional Antipodal Vivaldi Antenna (AVA) at higher frequencies. We propose a novel Metamaterial Lens Vivaldi Antenna (MLVA) design that overcomes this limitation by integrating an exponentially tapered antenna lens and a strategically placed Near Zero Refractive Index (NRZI) metamaterial lattice. The MLVA achieves exceptional wideband performance with a −3 dB gain bandwidth exceeding 148.6% from 3.7 to 25 GHz. The result demonstrates a peak realized gain of 11.8 dBi at 11.2 GHz, compared to 9.1 dBi conventional AVA, especially beyond 5 GHz. The compact MLVA design measures only 120 × 78 × 1.524 mm3 (1.48 × 0.96 × 0.0188λ03) λ0 where free‐space wavelength is the lowest frequency and is fabricated on RO4350 B substrate with a 50‐Ω SMA connector. Key features of the design include exponential flaring, and trapezoidal lens geometries chosen for their inherent ability to effectively collimate and direct the spherical wavefront. The incorporation of a dielectric lens and metasurface further enhances gain and Front‐to‐Back Ratio (FBR) by directing the majority of energy in the end‐fire direction. Experimental results validate the effectiveness of the proposed design, confirming simulation predictions. These outstanding characteristics make the MLVA a promising candidate for diverse wireless communication and radar applications demanding high data rates across a broad frequency range.

Boosting Low-E Electro-strain via High-Electronegativity B-Site Substitution in lead-free K0.5Na0.5NbO3-based ceramics

Lead-free piezoelectric actuators emerge as promising substitutes for their lead-containing counterparts to address environmental concerns. However, they often confront a trade-off between low driving electric fields and high electro-strain. Herein, a novel strategy to boost electro-strain under low electric fields is proposed by doping high-electronegativity B-site atoms into perovskite potassium sodium niobate-based ceramics. Our findings reveal that high-electronegativity B-site atoms elevate the covalency of B-O bonding, softening the short-range repulsion and introducing local multiphase coexistence. This leads to more nanoscale domain structures and lower coercive field, thereby enabling large strains to be produced at lower electric fields. Notably, a substantial 0.2% bipolar electro-strain and 0.1% unipolar electro-strain under 10kV cm-1 is achieved in Sr, Sb co-doped potassium sodium niobate ceramics, with a broad working frequency and temperature range, as well as excellent fatigue resistance. This study unveils innovative insights into designing lead-free piezoelectric ceramics with remarkable electro-strain performance and low driving electric field, promising a significant advancement in lead-free piezoelectric materials science and piezoelectric actuators.

Genesis and Propagation of Low‐Frequency Abyssal T‐Waves

AbstractAbyssal T‐waves are seismo‐acoustic waves originating from abyssal oceans. Unlike subduction‐zone‐generated slope T‐waves which are generated through multiple reflections between the sea surface and the gently dipping seafloor, the genesis of abyssal T‐waves cannot be explained by the same theory. Several hypotheses, including seafloor scattering, sea surface scattering, and internal‐wave‐induced volumetric scattering, have been proposed to elucidate their genesis and propagation. The elusive mechanism of abyssal T‐waves, particularly at low‐frequencies, hinders their use to quantify ocean temperatures through seismic ocean thermometry (SOT) and estimate oceanic earthquake parameters. Here, using realistic geophysical and oceanographic data, we first conduct numerical simulations to compare synthetic low‐frequency abyssal T‐waves under different hypotheses. Our simulations for the Romanche and Blanco transform faults suggest seafloor scattering as the dominant mechanism, with sea surface and internal waves contributing marginally. Short‐scale bathymetry can significantly enhance abyssal T‐waves across a broad frequency range. Also, observed T‐waves from repeating earthquakes in the Romanche, Chain, and Blanco transform faults exhibit remarkably high repeatability. Given the dynamic nature of sea surface roughness and internal waves, the highly repeatable T‐wave arrivals further support the seafloor scattering as the primary mechanism. The dominance of seafloor scattering makes abyssal T‐waves useable for constraining ocean temperature changes, thereby greatly expanding the data spectrum of SOT. Our observations of repeating abyssal T‐waves in the Romanche and Chain transform faults could provide a valuable data set for understanding Equatorial Atlantic warming. Still, further investigations incorporating high‐resolution bathymetry are warranted to better model abyssal T‐waves for earthquake parameter estimation.

Frequency stabilization of self-sustained oscillations in a sideband-driven electromechanical resonator

We present a method to stabilize the frequency of self-sustained vibrations in micromechanical and nanomechanical resonators. The method refers to a two-mode system with the vibrations at significantly different frequencies. The signal from one mode is used to control the other mode. In the experiment, self-sustained oscillations of micromechanical modes are excited by pumping at the blue-detuned sideband of the higher-frequency mode. Phase fluctuations of the two modes show near-perfect anticorrelation. They can be compensated in either of the modes by a stepwise change of the pump phase. The phase change of the controlled mode is proportional to the pump phase change, with the proportionality constant independent of the pump amplitude and frequency. This finding allows us to stabilize the phase of one mode against phase diffusion using the measured phase of the other mode. We demonstrate that phase fluctuations of either the high-frequency mode or the low-frequency mode can be significantly reduced. The results open new opportunities in generating stable vibrations in a broad frequency range via parametric down-conversion in nonlinear resonators. Published by the American Physical Society 2024

Design and experimentation of width tapered meandered array structure for low frequency broadband vibration energy harvesting

A novel 6DoF Tapered beam energy harvester, capable of operating across a broad and low frequency range, is proposed in this work. The hybrid structure incorporates regular beam array and zig-zag sections, enhancing deformation and bending. Width tapering with constant thickness optimizes the structural performance and energy harvesting capabilities of the beam. Tapering ensures even strain distribution, reducing the risk of structural failure. The proposed structure demonstrates wide band characteristics at low frequencies, delivering higher power output compared to an array of cantilevers for a given area. FEM analysis is conducted to optimize proof mass, aiming for closely spaced resonance frequencies and high-power output. Experimental validation on a prototype confirms the accuracy of the frequency response predicted by the models. Under harmonic base excitation of 0.4 g, the harvester yields an average DC power of 2497 μW, accounting for signal conditioning losses, within the frequency range of 9–20 Hz. The suggested structure offers excellent design flexibility, allowing adjustment of resonant frequencies by varying the number of beams, the slope and the proof mass of individual beams. The geometry of the proposed structure provides versatility, mechanical resilience, uniform strain distribution make it suitable for developing MEMS energy harvesters.