Angular control of multi-mode resonance frequencies in obliquely deposited CoZr thin films with rotatable stripe domains

We present a method to detect the non-uniform elastic property changes of sensor coatings on microcantilever arrays due to radiation, analyte binding or adsorption. The method uses measurements of the resonance frequencies of higher order flexural modes to identify with high sensitivity the location and magnitude of non-uniform elasticity changes in a microcantilever coating. We validate theoretical predictions and demonstrate the method by monitoring the time evolution of resonance frequencies of different flexural modes of microcantilevers functionalized with a small drop of a photosensitive polymer as it is exposed to ultraviolet (UV) radiation. The method is particularly well-suited for measuring quantitatively the time varying elastic properties of thin films or biological materials attached to microcantilevers.

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Nanostructured Gold Thin Films: Young Modulus Measurement

Surface Review and Letters ◽

10.1142/s0218625x03005323 ◽

2003 ◽

Vol 10 (04) ◽

pp. 571-575 ◽

Cited By ~ 12

Author(s):

M. C. Salvadori ◽

A. R. Vaz ◽

L. L. Melo ◽

M. Cattani

Keyword(s):

Thin Films ◽

Beam Theory ◽

Young Modulus ◽

Atomic Force ◽

Resonance Frequencies ◽

Before And After ◽

Nanostructured Gold ◽

Modulus Measurement ◽

Gold Thin Films ◽

Bulk Elastic Modulus

We have uniformly coated the cantilever of an atomic force microscope (AFM) with gold thin films. These films are nanostructured with thickness going from 19 to 62 nm. The resonance frequencies of this cantilever have been measured, before and after the Au coatings. Taking into account these frequencies and the vibrating beam theory, we determined the Young modulus of the Au films, obtaining E2 = 69.1 ± 2.6 GPa , i.e. about 12% lower than the respective bulk elastic modulus.

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Correlation of optical and microstructural properties of Gd2O3 thin films through phase-modulated ellipsometry and multi-mode atomic force microscopy

Applied Surface Science ◽

10.1016/s0169-4332(02)00900-5 ◽

2002 ◽

Vol 200 (1-4) ◽

pp. 219-230 ◽

Cited By ~ 31

Author(s):

N.K Sahoo ◽

M Senthilkumar ◽

S Thakur ◽

D Bhattacharyya

Keyword(s):

Thin Films ◽

Atomic Force Microscopy ◽

Microstructural Properties ◽

Force Microscopy ◽

Atomic Force ◽

Multi Mode ◽

Mode Atomic Force Microscopy

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Fabrication and Testing of a Micromirror Device Actuated by PZT Thin Films

Journal of Microelectronics and Electronic Packaging ◽

10.4071/1551-4897-3.4.209 ◽

2006 ◽

Vol 3 (4) ◽

pp. 209-215

Author(s):

Z.M. Xiao ◽

B.J. Chen ◽

H. Fan

Keyword(s):

Thin Films ◽

Plasma Etching ◽

Sol Gel ◽

Two Dimensional ◽

Release Process ◽

Scanning Angle ◽

Pzt Thin Films ◽

Resonance Frequencies ◽

Bimorph Beam

The paper describes the fabrication and characterization of two-dimensional resonant micromirror device actuated by sol-gel deposited PZT thin films. The actuation principle is based on the bimorph beam structure, which consists of an oxide layer and a piezoelectric PZT layer. The two-dimensional scanning performance can be achieved by applying AC voltages with phase shifts at resonance to the actuating beams. The devices are fabricated through thin film depositions, lithography, dry plasma etching and the ICP release process. For a micromirror structure with a 300μm ×300μm mirror plate, the first four resonance frequencies are measured to be in the range of 10–30 kHz. To investigate the vibration modes, the deflections on different locations of the mirror plate are measured. The two dimensional scanning angle is determined to be in one direction and 11° at 23.4 kHz in the perpendicular direction.

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Shape Synthesis of Multi-mode Dielectric Resonator Antennas Using Characteristic Modes

Applied Computational Electromagnetics Society ◽

10.47037/2020.aces.j.351109 ◽

2021 ◽

Vol 35 (11) ◽

pp. 1280-1281

Author(s):

Binbin Yang ◽

Abdullah Eroglu ◽

Jacob Adams

Keyword(s):

Cost Function ◽

Dielectric Resonator ◽

Mode Analysis ◽

Synthesis Process ◽

Modal Parameters ◽

Characteristic Mode ◽

Dielectric Resonator Antennas ◽

Resonance Frequencies ◽

The Cost ◽

Multi Mode

This paper demonstrates a shape synthesis technique for multi-mode dielectric resonator antennas using binary genetic algorithm and characteristic mode analysis. The cost function for the synthesis process is defined from characteristic modal parameters, such as modal quality factors and self-resonance frequencies. Since only modal parameters are involved in the cost function, the shape synthesis process is made independent of feeds. In the paper, we demonstrate the shape synthesis of a DRA with three self-resonant modes at 3 GHz.

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Multi-Mode Vibration Energy Harvester and Tuned Mass Damper Using Double-Beam Structure

Volume 7: Dynamic Systems and Control; Mechatronics and Intelligent Machines, Parts A and B ◽

10.1115/imece2011-64762 ◽

2011 ◽

Author(s):

Wanlu Zhou ◽

Gopinath Reddy Penamalli ◽

Lei Zuo

Keyword(s):

Energy Harvesting ◽

Energy Harvester ◽

Tuned Mass Damper ◽

Primary Beam ◽

Vibration Energy ◽

Piezoelectric Energy ◽

Resonance Frequencies ◽

Mass Damper ◽

Tip Mass ◽

Multi Mode

A novel piezoelectric energy harvester with multi-mode dynamic magnifier is proposed and investigated in this paper, which is capable of significantly increasing the bandwidth and the energy harvested from the ambient vibration. The design comprises of an multi-mode intermediate beam with a tip mass, called “dynamic magnifier”, and an “energy harvesting beam with a tip mass. The piezoelectric film is adhered to the harvesting beam to harvest the vibration energy. By properly designing the parameters, such as the length, width and thickness of the two beams and the weight of the two tip masses, we can virtually magnify the motion in all the resonance frequencies of the energy harvesting beam, in a similar way as designing a new beam-type tuned mass damper (TMD) to damp the resonance frequencies of all the modes of the primary beam. Theoretical analysis, finite element simulation, and the experiment study are carried out. The results show that voltage produced by the harvesting beam is amplified for efficient energy harvesting over a broader frequency range, while the peaks of the first three modes of the primary beam can be effectively mitigated simultaneously. The experiment demonstrates 25.5 times more energy harvesting capacity than the conventional cantilever type harvester in broadband frequency 3–300Hz, and over 1000 times more energy close to the first three resonances of harvesting beam.

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Anisotropic Elastic Properties of Chiral Sculptured Thin Films at Micro-Scale Evaluated by Resonance Frequency Spectra

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.645-646.9 ◽

2015 ◽

Vol 645-646 ◽

pp. 9-14

Author(s):

Hui Fang ◽

Kenta Matsumoto ◽

Takashi Sumigawa ◽

Takayuki Kitamura

Keyword(s):

Thin Films ◽

Elastic Properties ◽

Vibration Testing ◽

Frequency Spectra ◽

Sculptured Thin Films ◽

Micro Scale ◽

Surface Areas ◽

Resonance Frequencies ◽

Glancing Angle ◽

Anisotropic Elastic

Chiral sculptured thin films (STFs) Glancing-angle deposition (GLAD) thin films are nanoengineered to meet the requirements of a variety of applications such as micro filters, sensors, and waveguides due to their unique frequency characteristics which cannot be achieved by conventional solid materials. For the design, it is necessary to understand the elastic properties of STFs. To facilitate this, we report on our newly developed advanced micro-scale vibration testing process. In the testing, specially designed micro-specimens with surface areas of tens by tens of microns are excited using a piezoelectric (PZT) actuator and the resonance frequencies are detected by a laser device in the vertical or lateral directions successfully. The anisotropy elastic modulus of STFs composed of helical nanosprings are identified on the basis of vibration testing. The thin film shows strong characteristic anisotropy that the solid one hardly can attain. The micro-scale testing technique can be extended to other materials and microstructures.

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Validating the dynamic coefficients of bearing pedestals in a multi-mode rotor—bearing system

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1243/09544062jmes1161 ◽

2009 ◽

Vol 223 (6) ◽

pp. 1359-1378 ◽

Cited By ~ 2

Author(s):

T M Lim ◽

G B Chai

Keyword(s):

Frequency Domain ◽

Hypothesis Test ◽

Statistical Hypothesis ◽

Testing Time ◽

Finite Element Software ◽

Dynamic Coefficients ◽

Statistical Hypothesis Test ◽

Resonance Frequencies ◽

Rotor Bearing ◽

Multi Mode

Over the years, methods have been developed to estimate the dynamic coefficients of bearings based on parameter identification techniques. The stage where the estimated coefficients obtained from these methods need to be validated on actual operating machines, especially those operating at hypercritical speeds, has been reached. This article extended the frequency domain parameter estimation technique normally used on bearings to extract the dynamic coefficients of the bearing pedestals in isolation. It is demonstrated here that by using only a single forcing mechanism located at an angle to the bearing pedestal, the eight possible stiffness and damping coefficients can be estimated accurately. An on-line frequency domain algorithm for estimating these coefficients was developed and tested in the laboratory for this purpose. Its ability to reduce testing time and to produce reliable coefficient estimates from structural spurious resonance is observed. Validations of the dynamic coefficients of the bearing pedestals were carried out by comparing the experimental and computer simulated responses and resonance frequencies of the arrangement of two multi-mode rotor—bearing-system's configurations. By using ANSYS Inc. finite element software as a comparison tool, the results indicated that a nine stations rotor model formulated by the stiffness coefficient method is highly accurate at predicting the rotor—bearing system's responses and resonance frequencies. The results also confirmed that rotor bearing's synchronous response is insensitive with respect to individual estimated parameters that have been determined by statistical hypothesis test to be insignificant.

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