Frequency Of Cantilever Research Articles

Femtogram-Sensitive Cantilever Platform for Dynamic Graphene Oxide Nanosheet Monitoring.

This study introduces a new approach to optimizing graphene oxide (GO) properties using liquid-phase plasma treatment in a microenvironment. Our innovation exploits atomic force microscopy (AFM) cantilever frequency tracking to monitor mass variations in GO, which are indicative of surface oxidation-reduction processes or substituent doping (boron/nitrogen). Complementary in situ Raman spectroscopy has observed D/G band shifts, and X-ray photoelectron spectroscopy (XPS) determined the C/O ratio and B/N doping levels pre- and post-treatment, confirming chemical tuning to GO. We can achieve femtogram-level precision in detecting nanomaterial mass changes by correlating elemental ratios with AFM cantilever frequency measurements. This multifaceted approach not only enhances our understanding of the chemical properties of GO but also establishes a new, versatile method for monitoring, modifying, and optimizing the properties of nanomaterials.

Enhancing higher-order modal response in multifrequency atomic force microscopy with a coupled cantilever system.

Multifrequency atomic force microscopy (AFM) utilizes the multimode operation of cantilevers to achieve rapid high-resolution imaging and extract multiple properties. However, the higher-order modal response of traditional rectangular cantilever is weaker in air, which affects the sensitivity of multifrequency AFM detection. To address this issue, we previously proposed a bridge/cantilever coupled system model to enhance the higher-order modal response of the cantilever. This model is simpler and less costly than other enhancement methods, making it easier to be widely used. However, previous studies were limited to theoretical analysis and preliminary simulations regarding ideal conditions. In this paper, we undertake a more comprehensive investigation of the coupled system, taking into account the influence of probe and excitation surface sizes on the modal response. To facilitate the exploration of the effectiveness and optimal conditions for the coupled system in practical applications, a macroscale experimental platform is established. By conducting finite element analysis and experiments, we compare the performance of the coupled system with that of traditional cantilevers and quantify the enhancement in higher-order modal response. Also, the optimal conditions for the enhancement of macroscale cantilever modal response are explored. Additionally, we also supplement the characteristics of this model, including increasing the modal frequency of the original cantilever and generating additional resonance peaks, demonstrating the significant potential of the coupled system in various fields of AFM.

High-sensitivity narrow‑band T-shaped cantilever Fabry-perot acoustic sensor for photoacoustic spectroscopy

Photoacoustic spectroscopy (PAS) has been rapidly developed and applied to different detection scenarios. The acoustic pressure detection is an important part in the PAS system. In this paper, an ultrahigh sensitivity Fabry-Perot acoustic sensor with a T-shaped cantilever was proposed. To achieve the best acoustic pressure effect, the dimension of the cantilever structure was designed and optimized by finite element analysis using COMSOL Multiphysics. Simulation results showed that the sensitivity of such T-shaped cantilever was 1.5 times higher than that based on a rectangular cantilever, and the resonance frequency of T-shaped cantilever were able to modulate from 800 Hz to 1500 Hz by adjusting the multi-parameter characteristics. Experimental sensing results showed that the resonance frequency of T-shaped Fabry-Perot acoustic sensor was 1080 Hz, yielding a high sensitivity of 1.428 μm/Pa, with a signal-to-noise ratio (SNR) of 84.8 dB and a detectable pressure limit of 1.9 μPa/Hz1/2@1 kHz. We successfully used such acoustic sensor to measure acetylene (C2H2) concentration in the PAS. The sensitivity of PAS for C2H2 gas was 3.22 pm/ppm with a concentration range of 50 ppm ∼100 ppm, and the minimum detection limit was 24.91ppb.

Flexural resonant frequencies of an AFM cantilever in viscoelastic surface contact mode using modified nonlocal elasticity theory

Flexural resonant frequencies of an AFM cantilever in viscoelastic surface contact mode using modified nonlocal elasticity theory

Fiber-Optic Photoacoustic Gas Microsensor Dual Enhanced by Helmholtz Resonator and Interferometric Cantilever.

A high-sensitivity fiber-optic photoacoustic (PA) gas microsensor is demonstrated with dual enhancement based on acoustics and detection. Due to the characteristic of small size, a Helmholtz resonator is integrated into a miniature PA sensor. The acoustically amplified PA signal is detected by a high-sensitivity fiber Fabry-Perot (F-P) interferometric cantilever. The first-order resonant frequencies of the interferometric cantilever and Helmholtz resonator are matched by subtle adjustments. The weak PA signal is significantly enhanced in a volume of only 0.35 mL, which breaks the volume limitation of the resonance modes in traditional PA sensing systems. To improve the resolution of the microsensor, a white light interferometry (WLI)-based spectral demodulation algorithm is utilized. The experimental results indicate that the minimum detection limit of acetylene (C2H2) drops to about 15 ppb with an averaging time of 100 s, corresponding to the normalized noise equivalent absorption (NNEA) coefficient of 2.7 × 10-9 W·cm-1·Hz-1/2. The dual resonance enhanced fiber-optic PA gas microsensor has the merits of high sensitivity, intrinsic safety, and compact structure.

Enhancing nanoscale viscoelasticity characterization in bimodal atomic force microscopy.

Polymeric, soft, and biological materials exhibit viscoelasticity, which is a time dependent mechanical response to deformation. Material viscoelasticity emerges from the movement of a material's constituent molecules at the nano- and microscale in response to applied deformation. Therefore, viscoelastic properties depend on the speed at which a material is deformed. Recent technological advances, especially in atomic force microscopy (AFM), have provided tools to measure and map material viscoelasticity with nanoscale resolution. However, to obtain additional information about the viscoelastic behavior of a material from such measurements, theoretical grounding during data analysis is required. For example, commercially available bimodal AFM imaging maps two different viscoelastic properties of a sample, the storage modulus, E', and loss tangent, tan δ, with each property being measured by a different resonance frequency of the AFM cantilever. While such techniques provide high resolution maps of E' and tan δ, the different measurement frequencies make it difficult to calculate key viscoelastic properties of the sample such as: the model of viscoelasticity that describes the sample, the loss modulus, E'', at either frequency, elasticity E, viscosity η, and characteristic response times τ. To overcome this difficulty, we present a new data analysis procedure derived from linear viscoelasticity theory. This procedure is applied and validated by performing amplitude modulation-frequency modulation (AM-FM) AFM, a commercially available bimodal imaging technique, on a styrene-butadiene rubber (SBR) with known mechanical behavior. The new analysis procedure correctly identified the type of viscoelasticity exhibited by the SBR and accurately calculated SBR E, η, and τ, providing a useful means of enhancing the amount of information gained about a sample's nanoscale viscoelastic properties from bimodal AFM measurements. Additionally, being derived from fundamental models of linear viscoelasticity, the procedure can be employed for any technique where different viscoelastic properties are measured at different and discrete frequencies with applied deformations in the linear viscoelastic regime of a sample.

High performance fiber optic high frequency cantilever acoustical transducer based on PET film

High performance fiber optic high frequency cantilever acoustical transducer based on PET film

High-performance piezoelectric energy harvesting system with anti-interference capability for smart grid monitoring

This paper presents a piezoelectric energy harvesting device with anti-interference capability. The device utilizes magnetic coupling between the magnet at the tip of the piezoelectric cantilever and the alternating magnetic field surrounding power lines to efficiently harvest energy. Three piezoelectric cantilever structures are designed to optimize energy harvesting efficiency and space utilization. The impact of magnet interaction on the energy harvesting performance is investigated through theoretical analysis and experiments. The results demonstrate a decrease in the natural frequency of each piezoelectric cantilever due to magnet interaction. Frequency compensation techniques are applied to improve the overall output of the device. The anti-interference capability of the harvester is thoroughly evaluated, showing stable output even under random acceleration and the ability to withstand external interference. Additionally, the device successfully powers a wireless temperature and humidity sensor, validating its potential for self-powered wireless sensing nodes in grid monitoring systems.

Lissajous confocal fluorescent endomicroscopy with a lever mechanism and a frequency separation by an asymmetric polymer tube

We present a confocal fluorescent endomicroscopic system with a Lissajous scan using an asymmetric polymer tube and piezoelectric (PZT) tube actuator. The fiber cantilever’s scanning part is often inside the PZT tube actuator to reduce the scanner’s rigid length and enhance the beam deflection via a lever mechanism. Here, the mathematical model of the PZT tube actuator-based lever mechanism is first proposed by considering the piezoelectric parameters of the actuator and Euler-Bernoulli beam deflection, showing a good agreement with experimental data. In addition, an elliptical polymer tube is used to divide the resonant frequencies of the fiber cantilever, allowing enough scanning amplitudes and alleviating the inherent cross-coupling issue of a PZT tube actuator. The design optimization is performed by selecting the optimal lever length and the shape of the PFA tube. The implemented endomicroscopic probe could successfully acquire imaging results from both a lens-cleaning tissue and an ex-vivo mouse colon.

Optimization and Validation of Piezoelectric Cantilever Designs for Energy Harvesting from Bridge Vibrations

This study proposes an optimization strategy for bridge applications with a vibration-based energy harvester design. Piezoelectric cantilevers with multiple degrees of freedom (DOF) are designed and optimized to match resonant frequencies with the vibration frequencies of a full-scale bridge structure under different loading conditions and measurement locations. The specific optimization procedures include bridge vibration acceleration measurement, simulation model development for estimating the resonant frequencies, a regression model for optimization of mass combinations, and final installation on the full-scale bridge for validation. The results show that the simulation model predicted the resonant frequencies of cantilevers with less than 1 Hz difference compared with laboratory measurements. Following the entire optimization procedures proposed in this study, the optimized 2-DOF and 3-DOF cantilevers were capable of generating 18.9 [Formula: see text] J and 23.4 [Formula: see text] J energy under one loading pass, respectively, which were significantly higher than those from the baseline designs. The feasibility of the proposed optimization strategy was demonstrated and validated for vibration-based energy harvesting from bridge structures.

Study on ZnO and BaTiO3 for Low Frequency Applications

In this paper, we have discussed about piezo electric materials and its properties which are suitable for design and fabrication of low frequency applications. In this we have multiple of piezoelectric materials for the design of low frequency cantilever beam among them some of are here like, ceramic, lead zirconate titanate, composite material, barium titanate, quartz, pvdf, lithium niobate, lithium tantalate, zinc oxide, piezoelectric ceramics, among this here we compared two piezo electric materials they are P(VDF-TrFE) and copolymer such as ZnO and BaTiO3. This process has been done through polarization and annealing. Initially the process the process starts by simulation which includes calculation of polarization frequency of an compared elements, further the characterization of an BaTiO3 and ZnO will be done by oscilloscope and the fabrication of this materials will done through electrospinning.

Field Evaluation of Piezoelectric Energy Harvesters on Bridge Structure

This study aims to develop and evaluate vibration-based piezoelectric energy harvesters for generating power from a bridge structure. New designs of multiple-degree-of-freedom (DOF) cantilevers were proposed and evaluated in a laboratory and on a full-scale bridge. It was found that all cantilever designs showed potential of generating 35 V voltage outputs under a simple sinusoidal vibration scenario in the laboratory. Field testing results showed that the match between the vibration frequencies of bridge structure and the resonant frequencies of cantilevers significantly affected the voltage output from the piezoelectric energy harvester under moving tire loads. Through adding more DOF on the same cantilever, the voltage attenuation from peaks generated by the cantilever turned to be less significant after each load passing, leading to greater energy outputs in some cases. With adjusting the mass combination in the 3-DOF cantilever design, the voltage output and energy production reached 11.1 V and 58.2 μJ under one single loading pulse, respectively, which was higher than 9.2 V and 14.9 μJ obtained from the best scenario of 1-DOF cantilevers. The study findings indicate the potential of developing multi-band piezoelectric energy harvesters for harvesting energy from bridge vibrations.

A Gd‐Film Thermomagnetic Generator in Resonant Self‐Actuation Mode

AbstractThermomagnetic generation is a promising technology for conversion of low‐grade waste heat into electricity. Key requirements for the development of efficient thermomagnetic generators (TMGs) are tailored thermomagnetic materials as well as innovative designs enabling fast heat transfer. Recently, film‐based thermomagnetic generators are developed that operate in the mode of resonant self‐actuation enabling high frequency and stroke of a movable cantilever and, thus, efficient conversion of thermal energy into electrical energy. Here, the performance of a Gadolinium (Gd)‐film‐based TMG that is optimized for resonant self‐actuation near room temperature is reported. The Gd‐film TMG exhibits large oscillation frequencies up to 106 Hz and large strokes up to 2 mm corresponding to 38% of the oscillating cantilever's length. This performance occurs in a sharply bound range of ambient temperatures with an upper limit near the film's ferromagnetic to paramagnetic transition temperature Tc of 20 °C and of heat source temperatures ranging between 40 and 75 °C. The maximum power per footprint is 23.8 µWcm−2, at which the Gd film undergoes a temperature change of only 0.9 °C at ≈10 °C above Tc.

Research on a rotary piezoelectric wind energy harvester with bilateral excitation.

This paper describes a rotary piezoelectric wind energy harvester with bilateral excitation (B-RPWEH) that improves power generation performance. The power generating unit in the current piezoelectric cantilever wind energy harvester was primarily subjected to a periodic force in a single direction. The B-RPWEH adopted a reasonable bilateral magnet arrangement, thus avoiding the drawbacks of limited piezoelectric cantilever beam deformation and unstable power generation due to unidirectional excitation force. The factors affecting the power generation were theoretically analyzed, and the natural frequency and excitation force of the piezoelectric cantilever have been simulated and analyzed. A comprehensive experimental research method was used to investigate the output performance. The B-RPWEH reaches a maximum output voltage of 20.48Vpp when the piezoelectric sheet is fixed at an angle of 30°, the Savonius turbine number is 3, and the magnet diameter is 8mm. By adjusting the fixed angle of the piezoelectric sheet, the number of Savonius wind turbine blades, and the magnet diameter, the maximum voltage is increased by 52.38%, 4.49%, and 245.95%, respectively. The output power is 24.5 mW with an external resistor of 8 kΩ, and the normalized power density is 153.14 × 10-3 mW/mm3, capable of powering light-emitting diodes (LEDs). This structure can drive wireless networks or low-power electronics.

Dynamics analysis of width-varying microcantilevers: Interplay between eigenfrequencies, contact stiffness and interaction forces

In this study, the resonance-frequency dependence and modal sensitivity of the flexural vibration modes of overhang/T-shaped microcantilevers to the interaction force and surface stiffness variations were analysed, and a closed-form expression was derived. The Euler–Bernoulli beam theory was used to develop the overhang/T-shaped models, and a characteristic formula representing the dependence of cantilever frequencies on the overhang dimensions was obtained. The results of the derived expression were analysed using numerical simulations to investigate and compare the effects of the overhang width, length, repulsive and attractive forces, and surface contact stiffness on the flexural mode of overhang/T-shaped cantilevers. Furthermore, a closed-form expression for the modal sensitivities of the width-varying cantilever was derived, and the modal sensitivities were compared using numerical simulations. Finally, the effects of the interaction forces and contact stiffness on the frequency response and sensitivities of different cantilevers based on their stiffness and geometrical parameters were verified experimentally. This study can open new paths for designing, fabricating, and using width-varying cantilevers in sensing and imaging applications, particularly for cantilever array systems.

Vibration detection technology research based on piezoelectric cantilever

This paper studies the vibration detection technique based on the piezoelectric cantilever structure, and analyzes the relationship between the resonance frequency and the structure parameters. Although the output of the electrical signal is too small, it can be used to detect vibration during resonance with the maximum output voltage. A vibration testing device is designed based on piezoelectric cantilever structure, because in the vibration environment of the same frequency the vibration detection technology can obtain larger electrical signals. It can realize the automatic detection of real-time vibration state, and the vibration energy can charge the power supply through the energy storage circuit. Through the experimental method to verify relationship between the output voltage of piezoelectric cantilever beam, mass block, piezoelectric cantilever structure parameters and frequency, the experimental value of resonance frequency is very close with theoretical calculation value. The experimental resonant frequency of the designed piezoelectric cantilever beam is 16.5 Hz, which is slightly lower than the theoretical value of resonant frequency of 17.6 Hz, and the peak value of the piezoelectric output open-circuit voltage is 7.1 V.

Magnetic resonance force microscopy with matching frequencies of cantilever and spin

We have studied theoretically magnetic resonance force microscopy with a high-frequency nanomechanical cantilever when the cantilever frequency matches the resonant frequency of a single electron spin. Our analysis shows that in this situation, there is a small probability that the cantilever will oscillate with a large frequency shift. This can open new experimental opportunities for increasing the sensitivity in the detection of a single electron spin or even a single nuclear spin by using a high-frequency cantilever.

Dynamics of nonlinear cantilever piezoelectric–mechanical system: An intelligent computational approach

In this study, a novel application of intelligent computing by the exploitation of a supervised neural networks (SNNs) optimized with the Levenberg–Marquardt method (LMM) is presented to study the dynamics of nonlinear cantilever piezoelectric–mechanical system (NCPMS) represented with a second-order system of ordinary differential equation. The dataset for NCPMS is created using Adams numerical solver for input and target parameters for continuous mapping of SNN model of the system. The training, testing, and validation processes are exploited for SNNs models learned by LMM to determine the solution of NCPMS for different scenarios based on variation of amplitude and phase of cantilever frequency for small- and large-time domains while keeping the tip mass, beam length, mass density, capacitance and load resistance constant. The performance of SNN to solve NCPMS is substantiated on measurement of achieved accuracy through mean squared error, error histogram illustrations and regression analyzes.

Electron spin relaxation induced by a cantilever when the spin frequency matches the cantilever frequency

We study the electron spin relaxation induced by a high frequency nanomechanical cantilever with an attached ferromagnetic particle in a situation when the spin Larmor frequency matches the cantilever frequency. We consider a situation when the spin–cantilever system is described by the Jaynes–Cummings model. We have obtained an analytical solution describing the spin relaxation caused by the spin–cantilever interaction. Based on these results, we suggest a “spin thermometer” that could measure the temperature of nanomechanical cantilevers.

A Miniature Fiber-Optic Silicon Cantilever-Based Acoustic Sensor Using Ultra-High Speed Spectrum Demodulation

A silicon cantilever-based fiber-optic acoustic sensor (FOAS) is presented in this work. A rectangular cantilever is fabricated upon a silicon-on-insulator (SOI) wafer using a micro-electro-mechanical system (MEMS). The length, width and thickness of the silicon cantilever are 530 μm, 200 μm and 3 μm, respectively. The resonant frequency of the silicon cantilever is 14820 Hz with a sensitivity of 950 nm/Pa. An ultra-high speed absolute cavity length demodulation method is adopted using a complementary metal oxide semiconductor (CMOS) spectrometer and an 850 nm superluminescent light emitting diode (SLED). A modified Buneman frequency estimation and total phase demodulation algorithm is adopted. The frequency response curve shows a relatively flat trend from 20 Hz to 13 kHz. The sensor exhibits good linearities at different frequencies while the applied acoustic pressure is increased from 0 Pa to 2.5 Pa. Experimental results indicate that the minimum detectable pressure (MDP) of the proposed FOAS is calculated to be 25.68 μPa/Hz <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1/2</sup> at the frequency of 13 kHz. The silicon cantilever-based FOAS achieves broad operating bandwidth, high sensitivity, small size, and good stability.