scholarly journals Experimental Setup for Dynamic Analysis of Micro- and Nano-Mechanical Systems in Vacuum, Gas, and Liquid

Micromachines ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 162 ◽  
Author(s):  
Bram van den Brink ◽  
Farbod Alijani ◽  
Murali Ghatkesar
Keyword(s):  
Dynamic Analysis ◽  
Element Model ◽  
Dynamic Responses ◽  
Experimental Setup ◽  
Force Microscopy ◽  
Frequency Responses ◽  
Atomic Force ◽  
Different Types ◽  
Langevin Transducer ◽  
Good Agreement

An experimental setup to perform dynamic analysis of a micro- and nano-mechanical system in vacuum, gas, and liquid is presented. The setup mainly consists of a piezoelectric excitation part and the chamber that can be either evacuated for vacuum, or filled with gas or water. The design of the piezoelectric actuator was based on a Langevin transducer. The chamber is made out of materials that can sustain: vacuum, variety of gases and different types of liquids (mild acids, alkalies, common alcohols and oils). All the experiments were performed on commercial cantilevers used for contact and tapping mode Atomic Force Microscopy (AFM) with stiffness 0.2 N/m and 48 N/m, respectively, in vacuum, air and water. The performance of the setup was evaluated by comparing the measured actuator response to a finite element model. The frequency responses of the two AFM cantilevers measured were compared to analytical equations. A vacuum level of 0.6 mbar was obtained. The setup has a bandwidth of 10–550 kHz in vacuum and air, and a bandwidth of 50–550 kHz in liquid. The dynamic responses of the cantilevers show good agreement with theory in all media.

scholarly journals 3D phonon microscopy with sub-micron axial-resolution

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Richard J. Smith ◽  
Fernando Pérez-Cota ◽  
Leonel Marques ◽  
Matt Clark
Keyword(s):  
Signal To Noise Ratio ◽  
Single Cells ◽  
Optical Resolution ◽  
Acquisition Time ◽  
Label Free ◽  
Axial Resolution ◽  
Force Microscopy ◽  
Atomic Force ◽  
Accuracy And Precision ◽  
Good Agreement

AbstractBrillouin light scattering (BLS) is an emerging method for cell imaging and characterisation. It allows elasticity-related contrast, optical resolution and label-free operation. Phonon microscopy detects BLS from laser generated coherent phonon fields to offer an attractive route for imaging since, at GHz frequencies, the phonon wavelength is sub-optical. Using phonon fields to image single cells is challenging as the signal to noise ratio and acquisition time are often poor. However, recent advances in the instrumentation have enabled imaging of fixed and living cells. This work presents the first experimental characterisation of phonon-based axial resolution provided by the response to a sharp edge. The obtained axial resolution is up to 10 times higher than that of the optical system used to take the measurements. Validation of the results are obtained with various polymer objects, which are in good agreement with those obtained using atomic force microscopy. Edge localisation, and hence profilometry, of a phantom boundary is measured with accuracy and precision of approximately 60 nm and 100 nm respectively. Finally, 3D imaging of fixed cells in culture medium is demonstrated.

Effect of Surface Chemistry on Ruthenium Wet Etching

2021 ◽  
Vol 314 ◽  
pp. 302-306
Author(s):  
Quoc Toan Le ◽  
E. Kesters ◽  
M. Doms ◽  
Efrain Altamirano Sánchez
Keyword(s):  
Surface Roughness ◽  
Photoelectron Spectroscopy ◽  
Etching Rate ◽  
Wet Etching ◽  
X Ray ◽  
Force Microscopy ◽  
Metal Free ◽  
Atomic Force ◽  
Different Types ◽  
Effect Of Surface

Different types of ALD Ru films, including as-deposited, annealed Ru, without and with a subsequent CMP step, were used for wet etching study. With respect to the as-deposited Ru, the etching rate of the annealed Ru film in metal-free chemical mixtures (pH = 7-9) was found to decrease substantially. X-ray photoelectron spectroscopy characterization indicated that this behavior could be explained by the presence of the formation of RuOx (x = 2,3) caused by the anneal. A short CMP step applied to the annealed Ru wafer removed the surface RuOx, at least partially, resulting in a significant increase of the etching rate. The change in surface roughness was quantified using atomic force microscopy.

scholarly journals Simultaneous current, force and dissipation measurements on the Si(111) 7×7 surface with an optimized qPlus AFM/STM technique

2012 ◽  
Vol 3 ◽  
pp. 249-259 ◽  
Author(s):  
Zsolt Majzik ◽  
Martin Setvín ◽  
Andreas Bettac ◽  
Albrecht Feltz ◽  
Vladimír Cháb ◽  
...  
Keyword(s):  
Cross Talk ◽  
Tuning Fork ◽  
Tunneling Current ◽  
Quartz Tuning Fork ◽  
Scanning Tunneling ◽  
Experimental Setup ◽  
Force Microscopy ◽  
Atomic Force ◽  
Force Signal ◽  
Reported Data

We present the results of simultaneous scanning-tunneling and frequency-modulated dynamic atomic force microscopy measurements with a qPlus setup. The qPlus sensor is a purely electrical sensor based on a quartz tuning fork. If both the tunneling current and the force signal are to be measured at the tip, a cross-talk of the tunneling current with the force signal can easily occur. The origin and general features of the capacitive cross-talk will be discussed in detail in this contribution. Furthermore, we describe an experimental setup that improves the level of decoupling between the tunneling-current and the deflection signal. The efficiency of this experimental setup is demonstrated through topography and site-specific force/tunneling-spectroscopy measurements on the Si(111) 7×7 surface. The results show an excellent agreement with previously reported data measured by optical interferometric deflection.

Block Copolymer Microdomain Morphologies by Phase Detection Imaging

1996 ◽  
Vol 461 ◽  
Author(s):  
Ph. Leclère ◽  
J. M. Yu ◽  
R. Lazzaroni ◽  
Ph. Dubois ◽  
R. JéRôme ◽  
...  
Keyword(s):  
Scanning Probe Microscopy ◽  
Scanning Probe ◽  
Phase Detection ◽  
Surface Phase ◽  
Force Microscopy ◽  
Microscopy Technique ◽  
Atomic Force ◽  
Different Types ◽  
Microdomain Structure ◽  
Thermodynamic Processes

ABSTRACTAtomic Force Microscopy with Phase Detection Imaging is used to study the surface microdomain morphology of thick (i.e., ca. 2 mm) films of triblock copolymers, such as polymethylmethacrylate - block - polybutadiene - block - polymethylmethacrylate copolymers prepared by a well-taylored two-step sequential copolymerization promoted by a 1,3-diisopropenylbenzene based difunctional anionie initiator. By means of this new scanning probe microscopy technique, it is shown that the surface exhibits a segregated microphase structure, corresponding to the different types of components predicted theoretically by thermodynamic processes. We investigate the relationships between the size and characteristics of the microdomain structure as a function of the molecular parameters of the constituent polymers. Our data illustrate the interest of Phase Detection Imaging in the elucidation of surface phase separation in block copolymers.

Frequency Response of Carbon Nanotube Probes during Tapping Mode of Atomic Force Microscopy

2013 ◽  
Vol 378 ◽  
pp. 466-471
Author(s):  
Po Jen Shih ◽  
Shang Hao Cai
Keyword(s):  
Atomic Force Microscopy ◽  
Carbon Nanotube ◽  
Atomic Force Microscope ◽  
Frequency Response ◽  
Tapping Mode ◽  
Force Microscopy ◽  
Frequency Responses ◽  
Atomic Force ◽  
Frequency Drop ◽  
Atomic Force Microscope Measurement

The dynamic behaviors of carbon nanotube probes applied in Atomic Force Microscope measurement are of interest in advanced nanoscalar topography. In this paper, we developed the characteristic equations and applied the model analysis to solve the eigenvalues of the microcantilever and the carbon nanotube. The eigenvalues were then used in the tapping mode system to predict the frequency responses against the tip-sample separations. It was found that the frequency drop steeply if the separation was less than certain distances. This instability of frequency is deduced from the jump of microcantilever or the jump of the carbon nanotube. Various lengths and binding angles of the carbon nanotube were considered, and the results indicated that the binding angle dominated the frequency responses and jumps.

Dynamic Analysis of a Spur Geared Rotor-Bearing System with Nonlinear Gear Mesh Stiffness

2014 ◽  
Vol 945-949 ◽  
pp. 853-861 ◽  
Author(s):  
Ying Chung Chen ◽  
Chung Hao Kang ◽  
Siu Tong Choi
Keyword(s):  
Dynamic Analysis ◽  
Equations Of Motion ◽  
Element Model ◽  
Dynamic Responses ◽  
Mesh Stiffness ◽  
Gear Mesh ◽  
Lagrange’S Equation ◽  
Rotor Bearing ◽  
Gear Mesh Stiffness ◽  
Bearing System

The gear mesh stiffnesses have been regarded as constants in most previous models of geared rotor-bearing systems. In this paper, a dynamic analysis of a spur geared rotor-bearing system with nonlinear gear mesh stiffness is presented. The nonlinear gear mesh stiffness is accounted for by bending, fillet-foundation and contact deflections of gear teeth. A finite element model of the geared rotor-bearing system is developed, the equations of motion are obtained by applying Lagrange’s equation, and the dynamic responses are computed by using the fourth-order Runge-Kutta numerical method. Numerical results indicate that the proposed gear mesh stiffness provides a realistic dynamic response for spur geared rotor-bearing system.

Dynamic Analysis of an Elevator Traveling Cable Using a Singularity-Free Beam Formulation

2017 ◽  
Vol 84 (4) ◽  
Author(s):  
W. Fan ◽  
W. D. Zhu
Keyword(s):  
Dynamic Analysis ◽  
Multibody Dynamics ◽  
Natural Frequencies ◽  
Vertical Motion ◽  
Dynamic Responses ◽  
Mode Shapes ◽  
Out Of Plane ◽  
Forced Responses ◽  
Free Beam ◽  
Good Agreement

A round elevator traveling cable is modeled using a singularity-free beam formulation. Equilibria of the traveling cable with different elevator car positions are studied. Natural frequencies and the corresponding mode shapes of the traveling cable are calculated and they are in excellent agreement with those calculated by abaqus. In-plane natural frequencies of the traveling cable do not change much with the car position compared with its out-of-plane ones. Dynamic responses of the traveling cable are calculated and they are in good agreement with those from commercial multibody dynamics software recurdyn. Effects of vertical motion of the car on free responses of the traveling cable and those of in-plane and out-of-plane building sways on forced responses are investigated.

scholarly journals Theoretical study of the frequency shift in bimodal FM-AFM by fractional calculus

2012 ◽  
Vol 3 ◽  
pp. 198-206 ◽  
Author(s):  
Elena T Herruzo ◽  
Ricardo Garcia
Keyword(s):  
Fractional Calculus ◽  
Frequency Shift ◽  
Interaction Force ◽  
Simultaneous Recording ◽  
Force Microscopy ◽  
Simultaneous Excitation ◽  
Lennard Jones ◽  
Atomic Force ◽  
Different Types ◽  
Microscopy Method

Bimodal atomic force microscopy is a force-microscopy method that requires the simultaneous excitation of two eigenmodes of the cantilever. This method enables the simultaneous recording of several material properties and, at the same time, it also increases the sensitivity of the microscope. Here we apply fractional calculus to express the frequency shift of the second eigenmode in terms of the fractional derivative of the interaction force. We show that this approximation is valid for situations in which the amplitude of the first mode is larger than the length of scale of the force, corresponding to the most common experimental case. We also show that this approximation is valid for very different types of tip–surface forces such as the Lennard-Jones and Derjaguin–Muller–Toporov forces.

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