Response Measurement Accuracy for Off-Resonance Excitation in Atomic Force Microscopy

2010 ◽  
Author(s):  
Andrew J. Dick ◽  
R. Parker Eason
Keyword(s):  
Atomic Force Microscopy ◽  
Fundamental Frequency ◽  
Measurement Accuracy ◽  
Excitation Frequency ◽  
Resonance Excitation ◽  
Response Measurement ◽  
Force Microscopy ◽  
Atomic Force ◽  
Calibration Methods ◽  
Invaluable Tool

Dynamic atomic force microscopy (AFM) is an invaluable tool for characterizing and interacting with micro- and nano-scale systems. Standard measurement methods use a laser beam and a segmented photodiode to monitor the probe’s response. The diode reading is proportional to the slope of the probe and the displacement is obtained indirectly. As most operation methods use excitation around the fundamental frequency, calibration methods for determining the conversion factor to calculate the probe’s displacement are strongly inspired by the first vibrational mode shape. Within this paper, the results of an analytical study to predict measurement accuracy under non-standard excitation conditions with this calibration are presented. The influence of the excitation frequency, damping level, and laser spot location on this accuracy is investigated. The measurement accuracy for excitation at 2.5 times the fundamental frequency is of particular interest to the authors. Based upon the results, the use of a correction factor or a frequency-specific calibration is recommended.

Response Measurement Accuracy for Off-Resonance Excitation in Atomic Force Microscopy

2011 ◽  
Vol 134 (1) ◽  
Author(s):  
R. Parker Eason ◽  
Andrew J. Dick
Keyword(s):  
Atomic Force Microscopy ◽  
Measurement Accuracy ◽  
Excitation Frequency ◽  
Operating Conditions ◽  
Laser Spot ◽  
Resonance Excitation ◽  
Force Microscopy ◽  
Atomic Force ◽  
Mode Behavior ◽  
Tip Mass

Displacement measurement in atomic force microscopy (AFM) is most commonly obtained indirectly by measuring the slope of the AFM probe and applying a calibration factor. Static calibration techniques operate on the assumption that the probe response approximates single mode behavior. For off-resonance excitation or different operating conditions the contribution of higher modes may become significant. In this paper, changes to the calibrated slope-displacement relationship and the corresponding implications on measurement accuracy are investigated. A model is developed and numerical simulations are performed to examine the effect of laser spot position, tip mass, quality factor and excitation frequency on measurement accuracy. Free response conditions and operation under nonlinear tip-sample forces are considered. Results are verified experimentally using a representative macroscale system. A laser spot positioned at a nominal position between x = 0.5 and 0.6 is determined to minimize optical lever measurement error under conditions where the response is dominated by contributions from the first two modes, due to excitation as well as other factors.

Nonlinear Tapping-Tip Dynamics in Atomic Force Microscopy

2002 ◽  
Author(s):  
Soo Il Lee ◽  
Arvind Raman ◽  
Shuiqing Hu ◽  
Stephen W. Howell ◽  
Ron Reifenberger
Keyword(s):  
Nonlinear Dynamics ◽  
Atomic Force Microscopy ◽  
Nonlinear Response ◽  
Excitation Frequency ◽  
Computational Tools ◽  
Force Microscopy ◽  
Atomic Force ◽  
Highly Nonlinear ◽  
Intermittent Contact ◽  
Resolution Imaging

Tapping or intermittent contact atomic force microscopy (AFM) is widely used scanning probe techniques for high resolution imaging, manipulation and nanolithography. The presence of van der Waals forces and nanoscale impacts render highly nonlinear the dynamics of the AFM microcantilever while it operates in the tapping mode. A comprehensive nonlinear analysis of the nonlinear dynamics of AFM microcantilevers tapping on a nanostructure using the theoretical and computational tools of modern nonlinear dynamics has not yet been presented. Also, a rational connection between certain features of the tip-sample interaction potential and the nonlinear response has not been established satisfactorily. To address this problem, we have combined both experimental and nonlinear computational analysis of the tapping response of a microcantilever as a function of the excitation frequency. We show that this approach enables a comprehensive understanding of the nonlinear dynamic behavior observed in AFM experiments.

Atomic Force Microscopy Calibration Methods for Lateral Force, Elasticity, and Viscosity

1998 ◽  
Vol 522 ◽  
Author(s):  
C. K. Buenviaje ◽  
S.-R. Ge ◽  
M. H. Rafailovich ◽  
R. M. Overney
Keyword(s):  
Atomic Force Microscopy ◽  
Lateral Force ◽  
Force Microscopy ◽  
Atomic Force ◽  
Calibration Methods

scholarly journals Pulse-response measurement of frequency-resolved water dynamics on a hydrophilic surface using a Q-damped atomic force microscopy cantilever

2012 ◽  
Vol 3 ◽  
pp. 260-266
Author(s):  
Masami Kageshima
Keyword(s):  
Atomic Force Microscopy ◽  
Pulse Response ◽  
Water Dynamics ◽  
Control Technique ◽  
Response Measurement ◽  
Hydration Layer ◽  
Force Microscopy ◽  
Resonance Modes ◽  
Atomic Force ◽  
Atomic Force Microscopy Cantilever

The frequency-resolved viscoelasticity of a hydration layer on a mica surface was studied by pulse-response measurement of a magnetically driven atomic force microscopy cantilever. Resonant ringing of the cantilever due to its 1st and 2nd resonance modes was suppressed by means of the Q-control technique. The Fourier–Laplace transform of the deflection signal of the cantilever gave the frequency-resolved complex compliance of the cantilever–sample system. The significant viscoelasticity spectrum of the hydration layer was successfully derived in a frequency range below 100 kHz by comparison of data obtained at a distance of 300 nm from the substrate with those taken in the proximity of the substrate. A positive value of the real part of the stiffness was determined and is attributed to the reported solidification of the hydration layers.

scholarly journals Effect of Eigenmode Frequency on Loss Tangent Atomic Force Microscopy Measurements

2021 ◽  
Vol 11 (15) ◽  
pp. 6813
Author(s):  
Babak Eslami ◽  
Dylan Caputo
Keyword(s):  
Atomic Force Microscopy ◽  
Loss Tangent ◽  
Oscillation Amplitude ◽  
Excitation Frequency ◽  
Chemical Properties ◽  
Sample Surface ◽  
Force Microscopy ◽  
Atomic Force ◽  
Afm Cantilever ◽  
Tip Radius

Atomic Force Microscopy (AFM) is no longer used as a nanotechnology tool responsible for topography imaging. However, it is widely used in different fields to measure various types of material properties, such as mechanical, electrical, magnetic, or chemical properties. One of the recently developed characterization techniques is known as loss tangent. In loss tangent AFM, the AFM cantilever is excited, similar to amplitude modulation AFM (also known as tapping mode); however, the observable aspects are used to extract dissipative and conservative energies per cycle of oscillation. The ratio of dissipation to stored energy is defined as tanδ. This value can provide useful information about the sample under study, such as how viscoelastic or elastic the material is. One of the main advantages of the technique is the fact that it can be carried out by any AFM equipped with basic dynamic AFM characterization. However, this technique lacks some important experimental guidelines. Although there have been many studies in the past years on the effect of oscillation amplitude, tip radius, or environmental factors during the loss tangent measurements, there is still a need to investigate the effect of excitation frequency during measurements. In this paper, we studied four different sets of samples, performing loss tangent measurements with both first and second eigenmode frequencies. It is found that performing these measurements with higher eigenmode is advantageous, minimizing the tip penetration through the surface and therefore minimizing the error in loss tangent measurements due to humidity or artificial dissipations that are not dependent on the actual sample surface.

scholarly journals Determining amplitude and tilt of a lateral force microscopy sensor

2021 ◽  
Vol 12 ◽  
pp. 517-524
Author(s):  
Oliver Gretz ◽  
Alfred J Weymouth ◽  
Thomas Holzmann ◽  
Korbinian Pürckhauer ◽  
Franz J Giessibl
Keyword(s):  
Atomic Force Microscopy ◽  
Lateral Force ◽  
Scanning Tunneling ◽  
Two Dimensional ◽  
Local Surface ◽  
Lateral Force Microscopy ◽  
Tunneling Microscopy ◽  
Force Microscopy ◽  
Atomic Force ◽  
Calibration Methods

In lateral force microscopy (LFM), implemented as frequency-modulation atomic force microscopy, the tip oscillates parallel to the surface. Existing amplitude calibration methods are not applicable for mechanically excited LFM sensors at low temperature. Moreover, a slight angular offset of the oscillation direction (tilt) has a significant influence on the acquired data. To determine the amplitude and tilt we make use of the scanning tunneling microscopy (STM) channel and acquire data without and with oscillation of the tip above a local surface feature. We use a full two-dimensional current map of the STM data without oscillation to simulate data for a given amplitude and tilt. Finally, the amplitude and tilt are determined by fitting the simulation output to the data with oscillation.

Comparison of calibration methods for atomic-force microscopy cantilevers

2002 ◽  
Vol 14 (1) ◽  
pp. 1-6 ◽  
Author(s):  
N A Burnham ◽  
X Chen ◽  
C S Hodges ◽  
G A Matei ◽  
E J Thoreson ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Force Microscopy ◽  
Atomic Force ◽  
Calibration Methods
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