The effect of drive frequency and set point amplitude on tapping forces in atomic force microscopy: simulation and experiment

Harmonic atomic force microscopy (AFM) was employed to discriminate between different materials and to estimate the mixture ratio of the constituent components in nanocomposites. The major influencing factors, namely amplitude feedback set-point, drive frequency and laser spot position along the cantilever beam, were systematically investigated. Employing different set-points induces alternation of tip–sample interaction forces and thus different harmonic responses. The numerical simulations of the cantilever dynamics were well-correlated with the experimental observations. Owing to the deviation of the drive frequency from the fundamental resonance, harmonic amplitude contrast reversal may occur. It was also found that the laser spot position affects the harmonic signal strengths as expected. Based on these investigations, harmonic AFM was employed to identify material components and estimate the mixture ratio in multicomponent materials. The composite samples are composed of different kinds of nanoparticles with almost the same shape and size. Higher harmonic imaging offers better information on the distribution and mixture of different nanoparticles as compared to other techniques, including topography and conventional tapping phase. Therefore, harmonic AFM has potential applications in various fields of nanoscience and nanotechnology.

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Multi-Set Point Intermittent Contact (MUSIC) Mode Atomic Force Microscopy of Oligothiophene Fibrils

ACS Macro Letters ◽

10.1021/mz300025v ◽

2012 ◽

Vol 1 (3) ◽

pp. 380-383 ◽

Cited By ~ 18

Author(s):

Eike-Christian Spitzner ◽

Christian Riesch ◽

Ruth Szilluweit ◽

Liangfei Tian ◽

Holger Frauenrath ◽

...

Keyword(s):

Atomic Force Microscopy ◽

Set Point ◽

Force Microscopy ◽

Atomic Force ◽

Intermittent Contact ◽

Mode Atomic Force Microscopy

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A Method of Fabricating T Shape Nanochannel on Silicon Substrate

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.598.18 ◽

2014 ◽

Vol 598 ◽

pp. 18-22

Author(s):

Zone Ching Lin ◽

Hao Yuan Jheng ◽

Hao Yang Ding

Keyword(s):

Atomic Force Microscopy ◽

Silicon Substrate ◽

Si Substrate ◽

Cutting Depth ◽

Cutting Method ◽

Force Microscopy ◽

Single Pass ◽

Atomic Force ◽

Simulation And Experiment

The paper innovatively proposes using atomic force microscopy (AFM) and the concept of specific down force energy (SDFE) to establish a method for fabricating T shape nanochannel grooves on silicon (Si) substrate. Using the single-pass multi-layer cutting method of nanochannel groove using AFM proposed by the paper, a nanochannel looked like T shape is fabricated. For fabricating T shape nanochannel, it is set that cutting is firstly carried out for one pass on each cutting layer at a fixed down force. Then the probe carries out cutting for repeated passes. Using this cutting way by AFM and SDFE theory, the cutting depth and width of each pass can be predicted. The results of simulation and experiment of fabricating method for T shape nanochannel is further compared.

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