Probing viscoelastic surfaces with bimodal tapping-mode atomic force microscopy: Underlying physics and observables for a standard linear solid model

• Santiago D. Solares

Beilstein J. Nanotechnol. 2014, 5, 1649–1663, doi:10.3762/bjnano.5.176

• by using contact resonance techniques [4][5][6][7][8], whereby classical properties are approximated by using contact models under small-amplitude oscillatory deformations. Such characterization is much more challenging to carry out by using intermittent-contact techniques due to the non-linear

• the sample storage and loss moduli. Similarly, in contact resonance methods [4][5][6][7][8] the user generally measures the cantilever frequency response to small amplitude excitations, from which an effective resonance frequency and quality factor can be computed and post-processed to also give the

• observables and calculated quantities from the AFM measurement (frequency, phase, amplitude, quality factor, etc.) to the surface properties. In contact resonance typically the Kelvin–Voigt model [40] is used, which consists of a linear spring in parallel with a damper (dashpot). It is incorporated into the

Trade-offs in sensitivity and sampling depth in bimodal atomic force microscopy and comparison to the trimodal case

• Babak Eslami,
• Daniel Ebeling and
• Santiago D. Solares

Beilstein J. Nanotechnol. 2014, 5, 1144–1151, doi:10.3762/bjnano.5.125

• through changes in the amplitude of the highest driven eigenmode, which has the highest dynamic force constant (the higher stiffness of higher eigenmodes has also been advantageous in subsurface imaging applications in contact resonance AFM [18]). In this paper we show that indentation depth modulation

Frequency, amplitude, and phase measurements in contact resonance atomic force microscopies

• Gheorghe Stan and
• Santiago D. Solares

Beilstein J. Nanotechnol. 2014, 5, 278–288, doi:10.3762/bjnano.5.30

• , and phase response of the first two eigenmodes of two contact-resonance atomic force microscopy (CR-AFM) configurations, which differ in the method used to excite the system (cantilever base vs sample excitation), are analyzed in this work. Similarities and differences in the observables of the

• is provided. Keywords: contact-resonance AFM; dynamic AFM; frequency modulation; phase-locked loop; viscoelasticity; Introduction A number of atomic force microscopy (AFM) variants have emerged since the introduction of the original technique in 1986 [1]. Besides topographical acquisition and

• acoustic microscopy (AFAM) configuration [3]), such that the tip oscillation amplitude and its phase with respect to the excitation can be measured and converted into a loss and storage modulus. In contact resonance AFM (CR-AFM) [3][4][5][6][7][8][9] a similar setup is used, supplying the sinusoidal

Towards 4-dimensional atomic force spectroscopy using the spectral inversion method

• Jeffrey C. Williams and
• Santiago D. Solares

Beilstein J. Nanotechnol. 2013, 4, 87–93, doi:10.3762/bjnano.4.10

• folding/unfolding. For example, it should be possible to develop methods for fitting experimental data to increasingly elaborate viscoelastic models that go beyond the Kelvin–Voigt model used in the current state of the art in contact-resonance AFM [15][16]. In particular, the Kelvin–Voigt model is not

Mapping mechanical properties of organic thin films by force-modulation microscopy in aqueous media

• Jianming Zhang,
• Zehra Parlak,
• Carleen M. Bowers,
• Terrence Oas and
• Stefan Zauscher

Beilstein J. Nanotechnol. 2012, 3, 464–474, doi:10.3762/bjnano.3.53

• microscopy (AFAM) [31], and contact resonance AFM (CR-AFM) [32][33][34][35], contact resonance frequencies are deliberately chosen to enhance the imaging sensitivity. However, acoustic AFM imaging in solution is challenging since the liquid phase complicates the cantilever dynamics through fluid damping. To

• of a quantitative viscoelastic modeling approach in liquids, in analogy to those developed for contact resonance AFM in air [32][33]. Results and Discussion FMM working principles Linear regime in FMM In FMM, the cantilever tip contacts the substrate surface with a constant static force while a small

• frequencies significantly below the contact resonance frequency, the cantilever and the contact can be modeled as two springs in series (see Supporting Information File 1). In summary, the deflection of the cantilever, uc, measured by FMM is, where z0 is the actuation amplitude of the contact, ω is the

Manipulation of gold colloidal nanoparticles with atomic force microscopy in dynamic mode: influence of particle–substrate chemistry and morphology, and of operating conditions

• Samer Darwich,
• Karine Mougin,
• Akshata Rao,
• Enrico Gnecco,
• Shrisudersan Jayaraman and
• Hamidou Haidara

Beilstein J. Nanotechnol. 2011, 2, 85–98, doi:10.3762/bjnano.2.10

• Equation 1 [36]. UHV measurements The images in UHV were acquired with a custom built AFM available at the University of Basel [21]. The base pressure was below 10−9 mbar. Due to the high quality factor in UHV, the out-of-contact-resonance frequency shift was used as the imaging parameter instead of the

Scanning probe microscopy and related methods

• Ernst Meyer

Beilstein J. Nanotechnol. 2010, 1, 155–157, doi:10.3762/bjnano.1.18

• optical microscopy, SNOM: Scanning nearfield optical microscopy, TSM: Thermal scanning microscopy, cr-AFM: contact-resonance AFM, SPSTM: Spin polarized STM, SHPM: Scanning Hall probe microscopy, SGM: Scanning gate microscopy, SVM: Scanning voltage microscopy / Nanopotentiometry, ESR-STM: Electron spin