Mechanical Response of Diamond at Nanometer Scaes: Diamond Polishing and Atomic Force Microscopy

2000 ◽  
Vol 649 ◽  
Author(s):  
Ruben Pérez ◽  
Murray R. Jarvis ◽  
Michael C. Payne
Keyword(s):  
Chemical Nature ◽  
Mechanical Response ◽  
Normal Force ◽  
Single Atom ◽  
Mechanical Interaction ◽  
Contact Mode ◽  
Diamond Surfaces ◽  
Force Microscopy ◽  
Atomic Force ◽  
Diamond Polishing

ABSTRACTTotal energy pseudopotential methods are used to study two different processes involving the mechanical interaction of diamond nanoasperities and diamond surfaces: the wear processes reponsible for diamond polishing, an the mechanical deformation of tip and surface during the operation of the Atomic Force Microscope in contact Mode (CM-AFM). The strong asymmetry in the rate of polishing between different dirctions onthe diamond (110) surface is explained in terms of on atomistic mechanism for nano-groove formation. The pst–polishing surface morphology and the nature of the polishing residue epredicted by this mechanism are consistent with experimental evidence. In the case of CM-FAM, our calculations show that a tip terminated in a single atom is able to sustain forces in excess of 30 nN. The magnitude of the normal force was unexpectedlyfound to be verye similar for th approach on top of an atom or on a hollow position on the surface. This behaviour is due to tip relaxations induced by the interaction with the surface. These forces are also rather insensitive to the chemical nature of the tip apex.

The Adaptive Piezoelectric Microsensoriactuator for Active Control of Microcantilevers

2004 ◽  
Author(s):  
Steven Robert Burns ◽  
Daniel G. Cole ◽  
Robert L. Clark
Keyword(s):  
Mechanical Response ◽  
Contact Mode ◽  
Force Microscopy ◽  
Atomic Force ◽  
Resonance Response ◽  
Surface Image ◽  
The Difference ◽  
Micro Cantilever ◽  
Structure Sensor ◽  
Analog Circuitry

The adaptive piezoelectric sensoriactuator is modified for use at the microscale to facilitate non-contact mode imaging of a microcantilever MEMS device in atomic force microscopy. The sensoriactuator is a truly colocated (sensor and actuator occupy exactly the same position on the structure) sensor/actuator device that uses a hybrid digital and analog design to drive a structure while simultaneously sensing the mechanical response. Using a piezoelectric material to both sense and actuate simultaneously is problematic because of the difficulty in resolving the sensory (mechanical) and actuator (electrical) parts of the output signal. Implementation of the adaptive piezoelectric sensoriactuator at the microscale results in a system with electrical quantities that are vastly reduced or increased from typical macroscale values, requiring more precise components and more careful design and construction of analog circuitry. For example, a typical micro-cantilever piezoelectric has a capacitance of on the order of 100 pF with an impedance at 50 kHz nearly 32 kΩ. The signal levels are significantly smaller with a typical piezoelectric current on the order of 100 nA. Thus, environmental noise can overwhelm signals in the system mandating the use of high precision operational amplifiers featuring ultra-low bias currents (±30 fA) and careful guarding or shielding of all circuitry. As reported in this paper, the adaptive piezoelectric microsensoriactuator has been successfully used to simultaneously sense and actuate while imaging using non-contact mode. The self-sensing microcantilever was successfully tested to produce a surface image using the microsensoriactuator to measure the movement of the microcantilever. The RMS value of the microsensoriactuator output is compared with the desired RMS output and the difference is used to drive an active resonance response controller. The active resonance response controller determines the control signal required to augment or attenuate the microcantilever’s motion to match the desired motion.

Surface roughness measurements of vanadium-contaminated fluidized cracking catalysts by atomic force microscopy

1996 ◽  
Vol 54 ◽  
pp. 866-867
Author(s):  
H. Kinney ◽  
M.L. Occelli ◽  
S.A.C. Gould
Keyword(s):  
Surface Roughness ◽  
Zeolite Y ◽  
Atomic Level ◽  
Microporous Structure ◽  
Contact Mode ◽  
Force Microscopy ◽  
Atomic Force ◽  
Before And After ◽  
Roughness Measurements ◽  
Cracking Catalysts

For this study we have used a contact mode atomic force microscope (AFM) to study to topography of fluidized cracking catalysts (FCC), before and after contamination with 5% vanadium. We selected the AFM because of its ability to well characterize the surface roughness of materials down to the atomic level. It is believed that the cracking in the FCCs occurs mainly on the catalysts top 10-15 μm suggesting that the surface corrugation could play a key role in the FCCs microactivity properties. To test this hypothesis, we chose vanadium as a contaminate because this metal is capable of irreversibly destroying the FCC crystallinity as well as it microporous structure. In addition, we wanted to examine the extent to which steaming affects the vanadium contaminated FCC. Using the AFM, we measured the surface roughness of FCCs, before and after contamination and after steaming.We obtained our FCC (GRZ-1) from Davison. The FCC is generated so that it contains and estimated 35% rare earth exchaged zeolite Y, 50% kaolin and 15% binder.

scholarly journals Dynamic friction energy dissipation and enhanced contrast in high frequency bimodal atomic force microscopy

Friction ◽  
2021 ◽  
Author(s):  
Xinfeng Tan ◽  
Dan Guo ◽  
Jianbin Luo
Keyword(s):  
Atomic Force Microscopy ◽  
Energy Dissipation ◽  
Contact Friction ◽  
Measuring Instruments ◽  
Dynamic Friction ◽  
Contact Mode ◽  
Force Microscopy ◽  
Atomic Force ◽  
Friction Energy ◽  
New Applications

AbstractDynamic friction occurs not only between two contact objects sliding against each other, but also between two relative sliding surfaces several nanometres apart. Many emerging micro- and nano-mechanical systems that promise new applications in sensors or information technology may suffer or benefit from noncontact friction. Herein we demonstrate the distance-dependent friction energy dissipation between the tip and the heterogeneous polymers by the bimodal atomic force microscopy (AFM) method driving the second order flexural and the first order torsional vibration simultaneously. The pull-in problem caused by the attractive force is avoided, and the friction dissipation can be imaged near the surface. The friction dissipation coefficient concept is proposed and three different contact states are determined from phase and energy dissipation curves. Image contrast is enhanced in the intermediate setpoint region. The work offers an effective method for directly detecting the friction dissipation and high resolution images, which overcomes the disadvantages of existing methods such as contact mode AFM or other contact friction and wear measuring instruments.

scholarly journals Atomic force microscopy comparative analysis of the surface roughness of two posterior chamber phakic intraocular lens models: ICL versus IPCL

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Juan Gros-Otero ◽  
Samira Ketabi ◽  
Rafael Cañones-Zafra ◽  
Montserrat Garcia-Gonzalez ◽  
Cesar Villa-Collar ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Atomic Force Microscopy ◽  
Intraocular Lenses ◽  
Posterior Chamber ◽  
Anterior Surface ◽  
Contact Mode ◽  
Force Microscopy ◽  
Atomic Force ◽  
Phakic Intraocular Lenses ◽  
Roughness Measurements

Abstract Background To compare the anterior surface roughness of two commercially available posterior chamber phakic intraocular lenses (IOLs) using atomic force microscopy (AFM). Methods Four phakic IOLs were used for this prospective, experimental study: two Visian ICL EVO+ V5 lenses and two iPCL 2.0 lenses. All of them were brand new, were not previously implanted in humans, were monofocal and had a dioptric power of − 12 diopters (D). The anterior surface roughness was assessed using a JPK NanoWizard II® atomic force microscope in contact mode immersed in liquid. Olympus OMCL-RC800PSA commercial silicon nitride cantilever tips were used. Anterior surface roughness measurements were made in 7 areas of 10 × 10 μm at 512 × 512 point resolution. The roughness was measured using the root-mean-square (RMS) value within the given regions. Results The mean of all anterior surface roughness measurements was 6.09 ± 1.33 nm (nm) in the Visian ICL EVO+ V5 and 3.49 ± 0.41 nm in the iPCL 2.0 (p = 0.001). Conclusion In the current study, we found a statistically significant smoother anterior surface in the iPCL 2.0 phakic intraocular lenses compared with the VISIAN ICL EVO+ V5 lenses when studied with atomic force microscopy.

Contact and non-contact mode imaging by atomic force microscopy

1996 ◽  
Vol 273 (1-2) ◽  
pp. 138-142 ◽  
Author(s):  
Seizo Morita ◽  
Satoru Fujisawa ◽  
Eigo Kishi ◽  
Masahiro Ohta ◽  
Hitoshi Ueyama ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Contact Mode ◽  
Force Microscopy ◽  
Atomic Force

scholarly journals Friction and Mechanical Properties of AFM-Scan-Induced Ripples in Polymer Films

2021 ◽  
Vol 7 ◽  
Author(s):  
Sebastian Friedrich ◽  
Brunero Cappella
Keyword(s):  
Mechanical Properties ◽  
Polymer Films ◽  
Mechanical Response ◽  
Butyl Methacrylate ◽  
Clear Correlation ◽  
Contact Mode ◽  
Cantilever Deflection ◽  
Atomic Force ◽  
Volume Measurements ◽  
Force Volume

When compliant samples such as polymer films are scanned with an atomic force microscope (AFM) in contact mode, a periodic ripple pattern can be induced on the sample. In the present paper, friction and mechanical properties of such ripple structures on films of polystyrene (PS) and poly-n-(butyl methacrylate) (PnBMA) are investigated. Force volume measurements allow a quantitative analysis of the elastic moduli with nanometer resolution, showing a contrast in mechanical response between bundles and troughs. Additionally, analysis of the lateral cantilever deflection when scanning on pre-machined ripples shows a clear correlation between friction and the sample topography. Those results support the theory of crack propagation and the formation of voids as a mechanism responsible for the formation of ripples. This paper also shows the limits of the presented measuring methods for soft, compliant, and small structures. Special care must be taken to ensure that the analysis is not affected by artefacts.

scholarly journals Mechanical response of adherent giant liposomes to indentation with a conical AFM-tip

Soft Matter ◽  
2015 ◽  
Vol 11 (22) ◽  
pp. 4487-4495 ◽  
Author(s):  
Edith Schäfer ◽  
Marian Vache ◽  
Torben-Tobias Kliesch ◽  
Andreas Janshoff
Keyword(s):  
Mechanical Properties ◽  
Atomic Force Microscopy ◽  
Mechanical Response ◽  
Force Microscopy ◽  
Atomic Force

Mechanical properties of giant liposomes with actin cortices are determined with atomic force microscopy.

Conducting Polymer nanoComposites (CPC): Nanocharacterisation of layer by layer sprayed PMMA-CNT vapour sensors by Atomic force Microscopy in current Sensing Mode (CS-AFM)

2008 ◽  
Vol 1143 ◽  
Author(s):  
Bijandra Kumar ◽  
Mickaël Castro ◽  
Jianbo Lu ◽  
Jean-François Feller
Keyword(s):  
Atomic Force Microscopy ◽  
Spray Deposition ◽  
Dynamic Mode ◽  
Layer By Layer ◽  
Initial State ◽  
Contact Mode ◽  
Current Sensing ◽  
Multi Wall Carbon Nanotubes ◽  
Force Microscopy ◽  
Atomic Force

ABSTRACTOrganic vapour sensors based on poly (methylmethacrylate)-multi-wall carbon nanotubes (PMMA-CNT) conductive polymer nanocomposite (CPC) were developed via layer by layer technique by spray deposition. CPC Sensors were exposed to three different classes of solvents (chloroform, methanol and water) and their chemo-electrical properties were followed as a function of CNTcontent in dynamic mode. Detection time was found to be shorter than that necessary for full recovery of initial state. CNT real three dimensional network has been visualized by Atomic force microscopy in a field assisted intermittent contact mode. More interestingly real conductive network system and electrical ability of CPC have been explored by current-sensing atomic force microscopy (CS-AFM). Realistic effect of voltage on electrical conductivity has been found linear.

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