Comparison of photothermal and piezoacoustic excitation methods for frequency and phase modulation atomic force microscopy in liquid environments

Labuda, Aleksander; Kobayashi, Kei; Kiracofe, Daniel; Suzuki, Katsuyuki; Grütter, Peter; Yamada, Hirofumi

doi:10.1063/1.3601872

Cited by 65 publications

(84 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In some experimental conditions the second mode is not observed (A 2 = 0) as it is either too damped or falls outside the frequency range of the lock-in used for this experiment. Moreover, the presence of multiple peaks in the cantilever frequency response, resulting from the coupling between the acoustic excitation of the piezo and spurious mechanical modes [23,24], may sometime make it difficult to isolate the real resonance peak. In these cases, equation (1) was fitted by starting from the estimates given by the thermal noise spectrum and then 'enveloping' all the forest of peaks measured in AM mode under one single SHO peak.…”

Section: Dynamics Of Acoustically Excited Microcantilevers Immersed Imentioning

confidence: 99%

Nonlinear behaviour of self-excited microcantilevers in viscous fluids

Mouro

Tiribilli

Paoletti

2017

J. Micromech. Microeng.

View full text Add to dashboard Cite

Microcantilevers are increasingly being used to create sensitive sensors for rheology and mass sensing at the micro- and nano-scale. When operating in viscous liquids, the low quality factor of such resonant structures, translating to poor signal-to-noise ratio, is often manipulated by exploiting feedback strategies. However, the presence of feedback introduces poorly-understood dynamical behaviours that may severely degrade the sensor performance and reliability. In this paper, the dynamical behaviour of self-excited microcantilevers vibrating in viscous fluids is characterized experimentally and two complementary modelling approaches are proposed to explain and predict the behaviour of the closed-loop system. In particular, the delay introduced in the feedback loop is shown to cause surprising non-linear phenomena consisting of shifts and sudden-jumps of the oscillation frequency. The proposed dynamical models also suggest strategies for controlling such undesired phenomena.

show abstract

Section: Dynamics Of Acoustically Excited Microcantilevers Immersed Imentioning

confidence: 99%

Nonlinear behaviour of self-excited microcantilevers in viscous fluids

Mouro

Tiribilli

Paoletti

2017

J. Micromech. Microeng.

View full text Add to dashboard Cite

show abstract

“…The actuation of cantilevers in low Q environments can result in ≫ due to resonance coupling and a non-ideal actuator transfer function [35][36][37][38]. Under these conditions, the measured frequency shift, Δ , required to compensate Δ is reduced by ⁄ (see Ref [39] for an illustration):…”

Section: Phase Transfer Noisementioning

confidence: 99%

High viscosity environments: an unexpected route to obtain true atomic resolution with atomic force microscopy

et al. 2014

View full text Add to dashboard Cite

Atomic force microscopy (AFM) is widely used in liquid environments, where true atomic resolution at the solid-liquid interface can now be routinely achieved. It is generally expected that AFM operation in more viscous environments results in an increased noise contribution from the thermal motion of the cantilever, thereby reducing the signal-to-noise ratio (SNR). Thus, viscous fluids such as ionic and organic liquids have been generally avoided for highresolution AFM studies despite their relevance to, e.g. energy applications. Here, we investigate the thermal noise limitations of dynamic AFM operation in both low and high viscosity environments theoretically, deriving expressions for the amplitude, phase and frequency noise resulting from the thermal motion of the cantilever, thereby defining the performance limits of amplitude modulation (AM), phase modulation (PM) and frequency modulation (FM) AFM. We show that the assumption of a reduced SNR in viscous environments is not inherent to the technique and demonstrate that SNR values comparable to ultra-high vacuum systems can be obtained in high viscosity environments under certain conditions. Finally, we have obtained true atomic resolution images of highly ordered pyrolytic graphite and mica surfaces, thus revealing the potential of high-resolution imaging in high viscosity environments.High viscosity environments: an unexpected route to obtain true atomic resolution with atomic force microscopy 2

show abstract

“…11 These problems can largely be overcome using electrostatic excitation. In contrast to piezoacoustic actuation, electrostatic excitation only applies force to the AFM cantilever.…”

Section: Introductionmentioning

confidence: 99%

“…10 Even in cases where the cantilever resonance is not completely obscured, the resonance peak is often distorted, which can affect the accuracy of certain AFM techniques such as frequency modulation and phase modulation imaging. [11][12][13] Further, the spurious resonances can a) Author to whom correspondence should be addressed. Electronic mail:…”

Section: Introductionmentioning

confidence: 99%

Modular apparatus for electrostatic actuation of common atomic force microscope cantilevers

Long

Cannara

2015

Review of Scientific Instruments

View full text Add to dashboard Cite

Piezoelectric actuation of atomic force microscope (AFM) cantilevers often suffers from spurious mechanical resonances in the loop between the signal driving the cantilever and the actual tip motion. These spurious resonances can reduce the accuracy of AFM measurements and in some cases completely obscure the cantilever response. To address these limitations, we developed a specialized AFM cantilever holder for electrostatic actuation of AFM cantilevers. The holder contains electrical contacts for the AFM cantilever chip, as well as an electrode (or electrodes) that may be precisely positioned with respect to the back of the cantilever. By controlling the voltages on the AFM cantilever and the actuation electrode(s), an electrostatic force is applied directly to the cantilever, providing a near-ideal transfer function from drive signal to tip motion. We demonstrate both static and dynamic actuations, achieved through the application of direct current and alternating current voltage schemes, respectively. As an example application, we explore contact resonance atomic force microscopy, which is a technique for measuring the mechanical properties of surfaces on the sub-micron length scale. Using multiple electrodes, we also show that the torsional resonances of the AFM cantilever may be excited electrostatically, opening the door for advanced dynamic lateral force measurements with improved accuracy and precision.

show abstract

Comparison of photothermal and piezoacoustic excitation methods for frequency and phase modulation atomic force microscopy in liquid environments

Cited by 65 publications

References 26 publications

Nonlinear behaviour of self-excited microcantilevers in viscous fluids

Nonlinear behaviour of self-excited microcantilevers in viscous fluids

High viscosity environments: an unexpected route to obtain true atomic resolution with atomic force microscopy

Modular apparatus for electrostatic actuation of common atomic force microscope cantilevers

Contact Info

Product

Resources

About