Calibration of piezo actuators and systems by dynamic interferometry

• Knarik Khachatryan and
• Michael Reichling

Beilstein J. Nanotechnol. 2025, 16, 2086–2091, doi:10.3762/bjnano.16.143

• parts with high accuracy. This is commonly accomplished by piezo actuators, for instance, in the form of tube piezos for positioning the tip or optics. For their calibration, we propose an approach based on the dynamic response signal from a fiber interferometer used for cantilever displacement

• detection. The fine-positioning z-piezo of the fiber is calibrated by the analysis of measurements of the dynamic interferometer response signal recorded for various cantilever oscillation amplitudes and varied distances between the cantilever and the fiber end. Furthermore, we demonstrate the cantilever

• oscillation amplitude calibration under conditions of various amounts of tube piezo contraction and extension. The merits and limits of accuracy for such type of calibration are discussed. Keywords: cantilever excitation; fiber interferometer; NC-AFM; piezo calibration; non-contact atomic force microscopy

Multifrequency AFM integrating PeakForce tapping and higher eigenmodes for heterogeneous surface characterization

• Yanping Wei,
• Jiafeng Shen,
• Yirong Yao,
• Xuke Li,
• Ming Li and
• Peiling Ke

Beilstein J. Nanotechnol. 2025, 16, 2077–2085, doi:10.3762/bjnano.16.142

• nanoscale [1][2][3][4][5]. Among its various operating modes, tapping mode AFM is particularly prevalent due to lateral force minimization and its ability to give phase-contrast images of heterogeneous surfaces [6]. This mode involves oscillating the cantilever near its resonance frequency with the tip

• ]. The advent of multimodal AFM has extended the capabilities of tapping mode, exciting the cantilever at several eigenmode frequencies simultaneously. The amplitude of the primary eigenmode serves as feedback for topographical measurements, while the higher eigenmodes enhance material contrast. These

• factor (Q) cantilever dynamics amplify noise and demand meticulous parameter tuning [18]. To overcome these limitations, PeakForce tapping mode (PFT) was developed. It employs vertical probe oscillations at subresonant frequencies (0.5–8 kHz) to establish quasi-static tip–sample contact [18][19]. Unlike

Molecular and mechanical insights into gecko seta adhesion: multiscale simulations combining molecular dynamics and the finite element method

• Yash Jain,
• Saeed Norouzi,
• Tobias Materzok,
• Stanislav N. Gorb and
• Florian Müller-Plathe

Beilstein J. Nanotechnol. 2025, 16, 2055–2076, doi:10.3762/bjnano.16.141

• spatula was randomly selected from the set of ten uniquely generated spatula models (see subsection “Spatulae and substrate: particles”). Results and Discussion Forces, contacts, and displacement profiles AFM experiments measure forces exerted by the cantilever tip during pull-off, with the maximum

• pulling force representing the adhesion force between the spatula and the substrate [57]. These experiments typically report the force required to detach a spatula, but they are limited to measuring forces at the cantilever tip and cannot directly resolve molecular-scale interactions at the spatula

Mechanical property measurements enabled by short-term Fourier-transform of atomic force microscopy thermal deflection analysis

• Thomas Mathias,
• Roland Bennewitz and
• Philip Egberts

Beilstein J. Nanotechnol. 2025, 16, 1952–1962, doi:10.3762/bjnano.16.136

• reference material, rather than calculated directly from the dynamics models of the cantilever. We measured the cantilever displacement with very high sampling frequencies over the course of the experiment and captured its oscillations that result from thermal energy. Using short-term Fourier

• transformations, it was possible to fit the thermal resonance peak of the normal displacement to track the frequency and Q-factor of the cantilever during an experiment, using a similar process to that used to calibrate the normal bending stiffness of cantilevers. With this quantitative data, we have used the

• dynamic mechanics models relating the contact stiffness of the tip/cantilever pressing into a surface with the oscillation frequency of the cantilever and show that they did not accurately model the experiment. Several material combinations of tip and sample were examined; tip size and cantilever

Low-temperature AFM with a microwave cavity optomechanical transducer

• Ermes Scarano,
• Elisabet K. Arvidsson,
• August K. Roos,
• Erik Holmgren,
• Riccardo Borgani,
• Mats O. Tholén and
• David B. Haviland

Beilstein J. Nanotechnol. 2025, 16, 1873–1882, doi:10.3762/bjnano.16.130

• /bjnano.16.130 Abstract We demonstrate atomic force microscopy (AFM) imaging with a microcantilever force transducer where an integrated superconducting microwave resonant circuit detects cantilever deflection using the principles of cavity optomechanics. We discuss the detector responsivity and added

• noise, pointing to its crucial role in the context of force sensitivity. Through analysis of noise measurements we determine the effective temperature of the cantilever eigenmode and we determine the region of detector operation in which the sensor is thermal-noise-limited. Our analysis shows that the

• ]. The challenge for high-resolution AFM is designing such a detector for a test mass hosting a sharp tip that is scanned over a surface in ultrahigh vacuum and at ultralow temperature. In this paper, we report on an AFM cantilever force sensor with an integrated detector consisting of a compact

Venom-loaded cationic-functionalized poly(lactic acid) nanoparticles for serum production against Tityus serrulatus scorpion

• Philippe de Castro Mesquita,
• Karla Samara Rocha Soares,
• Manoela Torres-Rêgo,
• Emanuell dos Santos-Silva,
• Mariana Farias Alves-Silva,
• Alianda Maira Cornélio,
• Matheus de Freitas Fernandes-Pedrosa and
• Arnóbio Antônio da Silva-Júnior

Beilstein J. Nanotechnol. 2025, 16, 1633–1643, doi:10.3762/bjnano.16.115

• desiccator for 24 h. The images were obtained with a silicon tip, operating in the attractive region of a cantilever in non-contact mode. For the FEGSEM analyzes, a drop of dispersion was placed in a microscope slide with carbon tapes and dried under a desiccator for 24 h [46]. Protein-loading efficiency The

Mechanical stability of individual bacterial cells under different osmotic pressure conditions: a nanoindentation study of Pseudomonas aeruginosa

• Lizeth García-Torres,
• Idania De Alba Montero,
• Eleazar Samuel Kolosovas-Machuca,
• Facundo Ruiz,
• Sumati Bhatia,
• Jose Luis Cuellar Camacho and
• Jaime Ruiz-García

Beilstein J. Nanotechnol. 2025, 16, 1171–1183, doi:10.3762/bjnano.16.86

• displacement by the piezoelectric element are gathered in order to maintain a constant cantilever deflection or amplitude while a surface is scanned line by line Conversely, in FV quantitative information is extracted after analysis of a force–separation curve obtained from a performed nanoindentation

• a NanoScope V controller operated in fluid conditions throughout all experiments, using a pre-assembled fluid chamber with the appropriate solutions within a sealed O-ring. The instrument was operated in contact mode using MLCT probes from Bruker, cantilever D with a nominal spring constant of 0.03

• minimum damage to the mechanical integrity of the cell membrane. Before each experiment in FV mode, the cantilever was calibrated using the thermal-noise method which is integrated in the multimode AFM software and is briefly described next. First, the optical-lever sensitivity (OLS) of the cantilever was

Deep learning for enhancement of low-resolution and noisy scanning probe microscopy images

• Samuel Gelman,
• Irit Rosenhek-Goldian,
• Nir Kampf,
• Marek Patočka,
• Maricarmen Rios,
• Marcos Penedo,
• Georg Fantner,
• Amir Beker,
• Sidney R. Cohen and
• Ido Azuri

Beilstein J. Nanotechnol. 2025, 16, 1129–1140, doi:10.3762/bjnano.16.83

• described in [39]. Scans were made with a silicon tip on a silicon nitride cantilever (FASTSCANC, Bruker). The second set is composed of 25 pairs of low- and high-resolution images of a titanium film, which is used for AFM tip characterization (TipCheck, Aurora Nanodevices, BC, Canada). Images of 5 μm × 5

Shape, membrane morphology, and morphodynamic response of metabolically active human mitochondria revealed by scanning ion conductance microscopy

• Eric Lieberwirth,
• Anja Schaeper,
• Regina Lange,
• Ingo Barke,
• Simone Baltrusch and
• Sylvia Speller

Beilstein J. Nanotechnol. 2025, 16, 951–967, doi:10.3762/bjnano.16.73

• processes and warrants further investigation. Scanning probe microscopy (SPM) methods, such as atomic force microscopy (AFM), have been employed to image mitochondria in liquid, showing features of both the inner and outer membrane [22][23][24]. However, AFM measurements are influenced by the cantilever

• –sample interaction, often leading to an underestimation of mitochondrial apparent height due to applied cantilever pressure [22][25]. Similarly, scanning electron microscopy (SEM) offers high-resolution imaging but requires mitochondria to be chemically fixed, stained, and sectioned, which precludes the

• thus preventing the intermittency effect. A convolution effect, similar to the tip–sample convolution known from AFM, cannot account for the observed intermittency effect. The nanopipette tip exhibits an extremely high aspect ratio, in contrast to conventional AFM cantilever tips. A surface feature to

Tendency in tip polarity changes in non-contact atomic force microscopy imaging on a fluorite surface

• Bob Kyeyune,
• Philipp Rahe and
• Michael Reichling

Beilstein J. Nanotechnol. 2025, 16, 944–950, doi:10.3762/bjnano.16.72

• -ordered CaF2(111) [24][25], see [26] for further preparation details. RT experiments were performed with a UHV 750 AFM system (RHK, Troy, MI USA) operated at a base pressure of 7.0 × 10−11 mbar. An Ar+ ion-sputtered silicon cantilever with an eigenfrequency of around 300 kHz and a quality factor of 22000

• experiments were performed at 77 K using a LT UHV STM/AFM (ScientaOmicron, Taunusstein, Germany) operated at a base pressure of 5 × 10−10 mbar. NC-AFM measurements were conducted with a quartz cantilever based on a tuning fork [27] and a chemically etched tungsten tip attached to the end of the active prong

Thickness dependent oxidation in CrCl₃: a scanning X-ray photoemission and Kelvin probe microscopies study

• Shafaq Kazim,
• Rahul Parmar,
• Maryam Azizinia,
• Matteo Amati,
• Muhammad Rauf,
• Andrea Di Cicco,
• Seyed Javid Rezvani,
• Dario Mastrippolito,
• Luca Ottaviano,
• Tomasz Klimczuk,
• Luca Gregoratti and
• Roberto Gunnella

Beilstein J. Nanotechnol. 2025, 16, 749–761, doi:10.3762/bjnano.16.58

• cantilever coated with Pt at the resonance frequency of 68 kHz with an elastic constant of 1–5 N/m (AppNano) and doped diamond tips with 120 kHz and 8 N/m elastic constant (ADAMA). Kelvin probe force microscopy images were taken via double passage before and after applying an electric field by elevating the

The impact of tris(pentafluorophenyl)borane hole transport layer doping on interfacial charge extraction and recombination

• Konstantinos Bidinakis and
• Stefan A. L. Weber

Beilstein J. Nanotechnol. 2025, 16, 678–689, doi:10.3762/bjnano.16.52

• lock-in amplifier (Zurich Instruments), in an argon atmosphere glove box (less than 1% ppm O2 and negligible humidity). The cantilever used was SCM PIT V2 (resonance frequency: 75 kHz, spring constant: 3 N/m, Bruker). The scan rate of the measurement was 0.5 Hz. To increase the reliability of our data

• , we employed heterodyne-KPFM [55], whereby we mechanically excited the cantilever at its first resonant frequency, f1, and electrically excited at a frequency of (f2–f1), where f2 is the second resonant frequency [56]. Frequency mixing between the mechanical vibration at f1 and the electrostatic force

Nanoscale capacitance spectroscopy based on multifrequency electrostatic force microscopy

• Pascal N. Rohrbeck,
• Lukas D. Cavar,
• Franjo Weber,
• Peter G. Reichel,
• Mara Niebling and
• Stefan A. L. Weber

Beilstein J. Nanotechnol. 2025, 16, 637–651, doi:10.3762/bjnano.16.49

• method for nanoscale capacitance characterization at arbitrary frequencies above the second cantilever resonance. Besides a high spatial resolution, the key advantage of the multifrequency approach of MFH-EFM is that it measures the second-order capacitance gradient at almost arbitrary frequencies

• , SCM techniques face limitations due to nonlocal stray capacitances [40] from cantilever, tip cone, and the electrical connection, which hamper precise measurements and decrease resolution [55][61]. The advantage of SCFM methods is that capacitive forces depend on the first- or higher-order capacitance

• gradients with respect to the tip–sample distance, automatically canceling out the background capacitance caused by electrical connections and – to some degree – by the cantilever and the tip cone [24][25][55][56][57][58][59][60][61][62][63][64][65][66][67][68][69][70][71][72][73]. For example

Advanced atomic force microscopy techniques V

• Philipp Rahe,
• Ilko Bald,
• Nadine Hauptmann,
• Regina Hoffmann-Vogel,
• Harry Mönig and
• Michael Reichling

Beilstein J. Nanotechnol. 2025, 16, 54–56, doi:10.3762/bjnano.16.6

• et al. addresses the significantly increased precision of force spectroscopy measurements when performed with a quartz cantilever allowing to reduce the oscillation amplitude to values in the low picometer regime [2]. As the conversion of frequency-shift to force data critically depends on the

• accurate knowledge of the quartz cantilever stiffness, the authors develop a method to quantify the stiffness based on thermal noise measurements and numerical simulation. Calibrated measurements of conductivity and resistivity are the focus of the contribution by Piquemal et al. [3]. A particular

• . Khachartryan et al. highlight the strength of cantilever displacement detection with a Michelson-type fibre interferometer and provide a model for interferometric signal generation [4]. The interferometer response is slightly nonlinear under typical NC-AFM working conditions, while a large cantilever

New design of operational MEMS bridges for measurements of properties of FEBID-based nanostructures

• Bartosz Pruchnik,
• Krzysztof Kwoka,
• Ewelina Gacka,
• Dominik Badura,
• Piotr Kunicki,
• Andrzej Sierakowski,
• Paweł Janus,
• Tomasz Piasecki and
• Teodor Gotszalk

Beilstein J. Nanotechnol. 2024, 15, 1273–1282, doi:10.3762/bjnano.15.103

• different FIB parameters. An example of such a setup would be the cantilever described in [43]. On the base of the aligned opMEMS, a FEBID nanowire was deposited (Figure 7a) in a single-step process, where point-by-point deposition was performed along the pattern line using the following parameters: 5 keV

• stresses in thin films by deflecting a cantilever of defined size from a uniform membrane. We see a need for such experiments for future improvement of our proposed RoI spacing tuning method. The proposed approach allowed us to evaluate the leakage currents separately from the nanodevice properties. It was

Signal generation in dynamic interferometric displacement detection

• Knarik Khachatryan,
• Simon Anter,
• Michael Reichling and
• Alexander von Schmidsfeld

Beilstein J. Nanotechnol. 2024, 15, 1070–1076, doi:10.3762/bjnano.15.87

• to the harmonic displacement of the cantilever in the time domain. As the interferometer signal is limited in amplitude because of the spatial periodicity of the interferometer light field, an increasing cantilever oscillation amplitude creates an output signal with an increasingly complex temporal

• structure. By the fit of a model to the measured time-domain signal, all parameters governing the interferometric displacement signal can precisely be determined. It is demonstrated, that such an analysis specifically allows for the calibration of the cantilever oscillation amplitude with 2% accuracy

• between the light beams reflected from the fiber end (reference beam) and the cantilever (cavity beam), creating a standing wave pattern in the fiber with a spatial periodicity given by the light wavelength λ and a phase ϕ determined by the distance d between the fiber end and the cantilever. Any

Exploring surface charge dynamics: implications for AFM height measurements in 2D materials

• Mario Navarro-Rodriguez,
• Andres M. Somoza and
• Elisa Palacios-Lidon

Beilstein J. Nanotechnol. 2024, 15, 767–780, doi:10.3762/bjnano.15.64

• invasive mode, the driving excitation frequency can be fixed at, or near, the free resonance frequency of the cantilever, or tracked by using a phase-locked loop (PLL) to keep the system always in resonance. If the driving excitation frequency is kept fixed, the phase variations contain information about

Enhancing higher-order modal response in multifrequency atomic force microscopy with a coupled cantilever system

• Wendong Sun,
• Jianqiang Qian,
• Yingzi Li,
• Yanan Chen,
• Zhipeng Dou,
• Rui Lin,
• Peng Cheng,
• Xiaodong Gao,
• Quan Yuan and
• Yifan Hu

Beilstein J. Nanotechnol. 2024, 15, 694–703, doi:10.3762/bjnano.15.57

• traditional rectangular cantilever is weaker in air, which affects the sensitivity of multifrequency AFM detection. To address this issue, we previously proposed a bridge/cantilever coupled system model to enhance the higher-order modal response of the cantilever. This model is simpler and less costly than

• performance of the coupled system with that of traditional cantilevers and quantify the enhancement in higher-order modal response. Also, the optimal conditions for the enhancement of macroscale cantilever modal response are explored. Additionally, we also supplement the characteristics of this model

• , including increasing the modal frequency of the original cantilever and generating additional resonance peaks, demonstrating the significant potential of the coupled system in various fields of AFM. Keywords: atomic force microscopy; coupled system; higher-order modes; macroscale; multifrequency AFM

AFM-IR investigation of thin PECVD SiO_x films on a polypropylene substrate in the surface-sensitive mode

• Hendrik Müller,
• Hartmut Stadler,
• Teresa de los Arcos,
• Adrian Keller and
• Guido Grundmeier

Beilstein J. Nanotechnol. 2024, 15, 603–611, doi:10.3762/bjnano.15.51

• absorption of IR photons results in molecular vibrations in the material under investigation. This photon absorption also causes the thermal expansion of the material. The resulting photothermally generated tip–sample force is measured via changes in the deflection signal of the AFM cantilever. The

• of the cantilever was used as detection mode at 205 kHz. The drive mode was set to 845 kHz, which equals a higher contact resonance mode. The spectra were collected with a spectral resolution of 4 cm−1, and the phase-locked loop (PLL) was disabled for collecting the spectra. In addition to these

• source with two lock-in amplifiers. Nonlinear coupling of these processes in a small volume underneath the tip generates a surface expansion behavior containing the mixing frequencies, which are transferred into the cantilever deflection. Either the sum (C+M) or difference (C−M) frequency is chosen for

Stiffness calibration of qPlus sensors at low temperature through thermal noise measurements

• Laurent Nony,
• Sylvain Clair,
• Daniel Uehli,
• Aitziber Herrero,
• Jean-Marc Themlin,
• Andrea Campos,
• Franck Para,
• Alessandro Pioda and
• Christian Loppacher

Beilstein J. Nanotechnol. 2024, 15, 580–602, doi:10.3762/bjnano.15.50

• little precision. An accurate stiffness calibration is therefore mandatory if accurate force measurements are targeted. In nc-AFM, the probe may either be a silicon cantilever, a quartz tuning fork (QTF), or a length extensional resonator (LER). When used in ultrahigh vacuum (UHV) and at low temperature

• Calibration Methods: A Brief Review This section reminds some salient results about stiffness calibration methods reported in the literature, which forms the context of the present study. In the following, unless specified otherwise, the word “probe” either means a silicon cantilever or the free prong of a

• Equation 5. As for Q2 and Q3, there are few results in the literature on how they are expected to vary in UHV. Usually, the quality factor decreases with n (cf. [87] and silicon cantilever P5 in [56]). We therefore have set arbitrary values following that trend. The simulated temperature is 9.8 K. We first

Design, fabrication, and characterization of kinetic-inductive force sensors for scanning probe applications

• August K. Roos,
• Ermes Scarano,
• Elisabet K. Arvidsson,
• Erik Holmgren and
• David B. Haviland

Beilstein J. Nanotechnol. 2024, 15, 242–255, doi:10.3762/bjnano.15.23

• microscopy based on electromechanical coupling due to a strain-dependent kinetic inductance of a superconducting nanowire. The force sensor is a bending triangular plate (cantilever) whose deflection is measured via a shift in the resonant frequency of a high-Q superconducting microwave resonator at 4.5 GHz

• the coupling to the transmission line used to measure the microwave resonance. A detailed description of our fabrication is presented, including information about the process parameters used for each layer. We also discuss the fabrication of sharp tips on the cantilever using focused electron beam

• , gravitational waves acting on a 40 kg mirror in LIGO [3], or atomic-scale tip–surface forces acting on a 40 pg cantilever in an atomic force microscope (AFM). For AFM cantilevers operating at room temperature close to their fundamental resonant frequency in the kilohertz-to-megahertz range, optical

Quantitative wear evaluation of tips based on sharp structures

• Ke Xu and
• Houwen Leng

Beilstein J. Nanotechnol. 2024, 15, 230–241, doi:10.3762/bjnano.15.22

• , making it ideal for reverse imaging of the AFM probe tip to detect tip wear. AFM images were acquired using a Bruker Icon AFM system in tapping mode. The AFM probe used for AFM imaging was a Bruker FESPA-V2 probe. The cantilever was 225 µm long, 35 µm wide, and had a spring constant of 2.8 N/m. The

• working distance of 10–15 mm. Figure 7 presents an SEM image showcasing a probe tip with a rectangular cantilever and a triangular pyramid shape. The actual 3D morphology of the probe obtained using the 3D scanning results of the sample is shown in Figure 8. The analysis of the contour map of the probe

• scan images of the TipCheck sample. (a) 2D topography image and (b) 3D topography image. Extraction of scan line feature points. SEM images of AFM tips. (a) Image of tip and cantilever beam and (b) image of the tip; the dotted frame is a partially enlarged view of the tip. Reconstructed probe model. (a

Enhanced feedback performance in off-resonance AFM modes through pulse train sampling

• Mustafa Kangül,
• Navid Asmari,
• Santiago H. Andany,
• Marcos Penedo and
• Georg E. Fantner

Beilstein J. Nanotechnol. 2024, 15, 134–143, doi:10.3762/bjnano.15.13

• at frequencies far away from the resonance frequency of the cantilever (off-resonance tapping (ORT) modes) can provide high-resolution imaging of a wide range of sample types, including biological samples, soft polymers, and hard materials. These modes offer precise and stable control of vertical

• reads the deflection of the cantilever and keeps the applied tip–sample vertical force at a fixed setpoint value by adjusting the voltage applied to a Z axis nano-positioner. While this AFM mode achieves high precision in controlling vertical forces, the high lateral forces applied while scanning limits

• the application of this AFM method when gentle and non-damaging imaging is required, for instance on soft biological materials [1]. In order to make the instrument technique suitable for imaging fragile samples, several dynamic modes that rely on the resonance characteristics of the cantilever have

Determination of the radii of coated and uncoated silicon AFM sharp tips using a height calibration standard grating and a nonlinear regression function

• Perawat Boonpuek and
• Jonathan R. Felts

Beilstein J. Nanotechnol. 2023, 14, 1200–1207, doi:10.3762/bjnano.14.99

• strongly depend on the geometry of the AFM tip [7][8]. For example, the Pt-coated HQ:NSC18/Pt tip (for electrical force modulation AFM probes) and the Cr/Au-coated HQ:NSC16/Cr-Au tip (for tapping mode AFM probes with long AFM cantilever) produced by MikroMasch [9] have estimated nominal tip radii lower

• very sharp tips that can make a smaller difference in the scanned profile offset at the corners of the characterizer. A method for characterizing blunt tips was also demonstrated. Nanoindentation using four blunt tips on an AFM cantilever was performed in a normal loading process on a soft PVC sheet

• this measurement, the tip radius profile can be directly determined by the deflection and position signal of the AFM cantilever during contact between that edge surface and the tip end. Our point of interest for determining the tip radius using this standard grate is that the corner edge of the grate

Spatial variations of conductivity of self-assembled monolayers of dodecanethiol on Au/mica and Au/Si substrates

• Julian Skolaut,
• Jędrzej Tepper,
• Federica Galli,
• Wulf Wulfhekel and
• Jan M. van Ruitenbeek

Beilstein J. Nanotechnol. 2023, 14, 1169–1177, doi:10.3762/bjnano.14.97

• . In this mode of CAFM operation, a force–distance curve is measured at every pixel of the image. The tip is approached until a certain bend of the cantilever is reached, corresponding to the force setpoint Fsetpoint. Plotting the z position at which the force setpoint is reached provides the