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

• rate and therefore enables higher scan rates while refining the mechanical property mapping. Keywords: atomic force microscopy (AFM); feedback control; off-resonance tapping (ORT); pulsed-force mode; Introduction Constant force mode, a widely used AFM imaging mode, utilizes a feedback controller that

• before reaching the reference interaction window. Conclusion ORT modes offer the advantage of gentle probing and the ability to perform multiparametric imaging. However, the sampling rate of the feedback control significantly decreases to the kilohertz range compared to the megahertz range in contact

Thermophoretic tweezers for single nanoparticle manipulation

• Jošt Stergar and
• Natan Osterman

Beilstein J. Nanotechnol. 2020, 11, 1126–1133, doi:10.3762/bjnano.11.97

• -time force feedback can also be implemented with optical tweezers [14][15][16]. Recently, systems based on high-precision position detection and feedback control running at 100 kHz have been employed to generate arbitrary potentials for micrometer-sized particles [17][18]. A less commonly used

• with sizes of 1 μm and 200 nm in an aqueous medium. We model the effect with an overdamped Langevin dynamics simulation to obtain quantitative predictions. Since the feedback control algorithm can be easily modified, the resulting particle trapping potential can be thus arbitrarily shaped. We show this

Measurement of electrostatic tip–sample interactions by time-domain Kelvin probe force microscopy

• Christian Ritz,
• Tino Wagner and
• Andreas Stemmer

Beilstein J. Nanotechnol. 2020, 11, 911–921, doi:10.3762/bjnano.11.76

• used for optimal feedback control during this measurement [13]. The results of the standard technique are shown in Figure 4a–c. A second measurement was carried out using the TD-KFM controller. The topography-induced frequency shift was used as control signal for the height feedback in this case. The

Comparison of fresh and aged lithium iron phosphate cathodes using a tailored electrochemical strain microscopy technique

• Matthias Simolka,
• Hanno Kaess and
• Kaspar Andreas Friedrich

Beilstein J. Nanotechnol. 2020, 11, 583–596, doi:10.3762/bjnano.11.46

• of the sample and the deflection error of the AFM tip are recorded. The deflection error represents the feedback signal of the feedback control system for the tip–sample contact force control and is the difference between the set point and the effective value. The ESM signal is based on the real, in

Atomic-resolution imaging of rutile TiO₂(110)-(1 × 2) reconstructed surface by non-contact atomic force microscopy

• Daiki Katsube,
• Shoki Ojima,
• Eiichi Inami and
• Masayuki Abe

Beilstein J. Nanotechnol. 2020, 11, 443–449, doi:10.3762/bjnano.11.35

• feedback control was applied in frequency-modulation mode [30] with constant amplitude oscillation. The cantilever deflection was detected using an optical interferometer [31]. Since the electrostatic force due to the contact potential difference (CPD) between the tip and sample prevents high-resolution NC

A scanning probe microscopy study of nanostructured TiO₂/poly(3-hexylthiophene) hybrid heterojunctions for photovoltaic applications

• Laurie Letertre,
• Roland Roche,
• Olivier Douhéret,
• Hailu G. Kassa,
• Denis Mariolle,
• Nicolas Chevalier,
• Łukasz Borowik,
• Philippe Dumas,
• Benjamin Grévin,
• Roberto Lazzaroni and
• Philippe Leclère

Beilstein J. Nanotechnol. 2018, 9, 2087–2096, doi:10.3762/bjnano.9.197

• configuration considering no feedback control (right part) and feedback control (left part). The blue (orange) lines correspond to the situation in the dark (under illumination). eΔV (green color) represents the bond dipole in the dark, while eΔVlight (orange color) represents the photovoltage under

Quantitative comparison of wideband low-latency phase-locked loop circuit designs for high-speed frequency modulation atomic force microscopy

• Kazuki Miyata and
• Takeshi Fukuma

Beilstein J. Nanotechnol. 2018, 9, 1844–1855, doi:10.3762/bjnano.9.176

• signal is output from the PLL and used for tip–sample distance feedback control. Meanwhile, the VCO output is employed to excite cantilever oscillations, forming the cantilever excitation loop depicted in Figure 1a. Similarly to a general lock-in amplifier, an M-PLL utilizes a multiplication-based PC

Lyapunov estimation for high-speed demodulation in multifrequency atomic force microscopy

• David M. Harcombe,
• Michael G. Ruppert,
• Michael R. P. Ragazzon and
• Andrew J. Fleming

Beilstein J. Nanotechnol. 2018, 9, 490–498, doi:10.3762/bjnano.9.47

• interactions [2], atomic scale resolution imaging is achieved, which far exceeds the optical diffraction limit. An image generated by constant-force topography AFM depends entirely on its feedback control loop. The composition of a sample is visualized in three-dimensions by plotting the control signal against

The nanofluidic confinement apparatus: studying confinement-dependent nanoparticle behavior and diffusion

• Stefan Fringes,
• Felix Holzner and
• Armin W. Knoll

Beilstein J. Nanotechnol. 2018, 9, 301–310, doi:10.3762/bjnano.9.30

• of the nanofluidic confinement apparatus. We vary the gap distance for different measurements and then use the feedback-control loop to keep it constant (see Figure 2e) while acquiring frames for 15 s. The number of particles in the field of view reduces with decreasing gap distance. In our

High-speed dynamic-mode atomic force microscopy imaging of polymers: an adaptive multiloop-mode approach

• Juan Ren and
• Qingze Zou

Beilstein J. Nanotechnol. 2017, 8, 1563–1570, doi:10.3762/bjnano.8.158

• deflection (the TM deflection) – in addition to the transitional RMS amplitude feedback control, along with an online iterative feedforward control to track the sample topography. Although this AMLM technique has been proposed recently [1], imaging results of only one polymer sample at large scanning size

• track the sample topography by the AFM z-axis piezo. AMLM imaging introduces a feedback control of inner–outer loop structure to regulate the mean cantilever deflection per vibration period (called the TM-deflection). Thus the averaged (vertical) position of the cantilever in each tapping period is kept

• ]. As the TM-deflection responds much faster than the RMS tapping-amplitude to the sample topography variation, so the inner-outer loop feedback control of the TM-deflection is faster than that of the RMS tapping amplitude. Moreover, the TM-deflection feedback loop facilitates the regulation of the

Analysis and modification of defective surface aggregates on PCDTBT:PCBM solar cell blends using combined Kelvin probe, conductive and bimodal atomic force microscopy

• Hanaul Noh,
• Alfredo J. Diaz and
• Santiago D. Solares

Beilstein J. Nanotechnol. 2017, 8, 579–589, doi:10.3762/bjnano.8.62

• . (a)–(d) Topographies consecutively obtained by tapping-mode bimodal AFM using the first eigenmode of the cantilever for the distance feedback control and the third eigenmode for modulating indentation. (e)–(h) The third eigenmode amplitude signal, corresponding to a free amplitude of about 3 nm

Dynamic of cold-atom tips in anharmonic potentials

• Tobias Menold,
• Peter Federsel,
• Carola Rogulj,
• Hendrik Hölscher,
• József Fortágh and
• Andreas Günther

Beilstein J. Nanotechnol. 2016, 7, 1543–1555, doi:10.3762/bjnano.7.148

• atoms and could possibly allow for active feedback control of the tip motion. Methods like Q-control [33][34], which have been very successful in conventional force microscopy [35][36], are therefore realizable. The article is structured as follows: We start by describing the theory of tip motion in

Length-extension resonator as a force sensor for high-resolution frequency-modulation atomic force microscopy in air

• Hannes Beyer,
• Tino Wagner and
• Andreas Stemmer

Beilstein J. Nanotechnol. 2016, 7, 432–438, doi:10.3762/bjnano.7.38

• constant amplitude of 1.1 nm on a KBr(001) single crystal surface after cleavage in air. The initial excitation is 2.961 mV. Application of the slow feedback control. a) Evolution of frequency shift Δf (black), frequency shift offset Δfoffset (red), and dew point (blue) over 140 min. b) Large scale

Development of a novel nanoindentation technique by utilizing a dual-probe AFM system

• Eyup Cinar,
• Ferat Sahin and
• Dalia Yablon

Beilstein J. Nanotechnol. 2015, 6, 2015–2027, doi:10.3762/bjnano.6.205

• response curve with an inset including the change of phase over frequency. As the plots indicate, the tuning fork probes have a very sharp resonance curve enabling a sensitive error signal with accurate closed-loop feedback control. Depending on the application, it is possible to configure the system to be

Graphene on SiC(0001) inspected by dynamic atomic force microscopy at room temperature

• Mykola Telychko,
• Jan Berger,
• Zsolt Majzik,
• Pavel Jelínek and
• Martin Švec

Beilstein J. Nanotechnol. 2015, 6, 901–906, doi:10.3762/bjnano.6.93

• graphene honeycomb structure modulated by the q-6 periodicity. The Δf signal shows the honeycomb structure and the q-6 modulation as well. In this case, the slow feedback control of the tip–sample distance allows us to stay in the repulsive regime, achieving atomic resolution. This would be otherwise

Electroburning of few-layer graphene flakes, epitaxial graphene, and turbostratic graphene discs in air and under vacuum

• Andrea Candini,
• Nils Richter,
• Domenica Convertino,
• Camilla Coletti,
• Franck Balestro,
• Wolfgang Wernsdorfer,
• Mathias Kläui and
• Marco Affronte

Beilstein J. Nanotechnol. 2015, 6, 711–719, doi:10.3762/bjnano.6.72

• the resistance is observed [10]. When the measured resistance overcomes a fixed value corresponding to the complete formation of an open gap in the device, a feedback control of our electronics restores the voltage to zero very rapidly (<100 µs). The complete process takes approximately 10 to 20 s

Characterization of 10,12-pentacosadiynoic acid Langmuir–Blodgett monolayers and their use in metal–insulator–metal tunnel devices

• Saumya Sharma,
• Mohamad Khawaja,
• Manoj K. Ram,
• D. Yogi Goswami and
• Elias Stefanakos

Beilstein J. Nanotechnol. 2014, 5, 2240–2247, doi:10.3762/bjnano.5.233

• concentration of PDA dissolved in chloroform. The surface tension was measured using a paper Wilhelmy plate suspended in the water in the LB trough. The deposition conditions were regulated using surface tension and compression feedback control. This resulted in the formation of a closely packed film at the air

In situ growth optimization in focused electron-beam induced deposition

• Paul M. Weirich,
• Marcel Winhold,
• Christian H. Schwalb and
• Michael Huth

Beilstein J. Nanotechnol. 2013, 4, 919–926, doi:10.3762/bjnano.4.103

• changing the deposition parameters. Here, we present a first implementation of such a feedback control mechanism and employ an evolutionary genetic algorithm (GA) for the in situ optimization of the electrical conductivity of nanostructures that are prepared by FEBID [17]. By using the time gradient of the

Size-dependent characteristics of electrostatically actuated fluid-conveying carbon nanotubes based on modified couple stress theory

• Mir Masoud Seyyed Fakhrabadi,
• Abbas Rastgoo and
• Mohammad Taghi Ahmadian

Beilstein J. Nanotechnol. 2013, 4, 771–780, doi:10.3762/bjnano.4.88

• the larger tube can be the movable part of the system as considered in this paper, and the other parts such as graphene sheets and actuation devices can be added to the considered section of the nanotube (Figure 3). Another application of the system is its utilization for feedback control. A control

Multiple regimes of operation in bimodal AFM: understanding the energy of cantilever eigenmodes

• Daniel Kiracofe,
• Arvind Raman and
• Dalia Yablon

Beilstein J. Nanotechnol. 2013, 4, 385–393, doi:10.3762/bjnano.4.45

• bistability by using frequency modulation, phase modulation or other newer feedback control schemes, such as drive modulation. From a theoretical point of view, more research is needed to understand the nature of the different states and exactly why the contrast should reverse. The fact that there is no

High-resolution dynamic atomic force microscopy in liquids with different feedback architectures

• John Melcher,
• David Martínez-Martín,
• Miriam Jaafar,
• Julio Gómez-Herrero and
• Arvind Raman

Beilstein J. Nanotechnol. 2013, 4, 153–163, doi:10.3762/bjnano.4.15

• forces can be remarkable similar. Furthermore, the reduction in noncontact forces and quality factors in liquids diminishes the role of feedback control in achieving high-resolution images. The theoretical findings are supported by atomic-resolution images of mica in water acquired with AM, FM and DAM

• of imaging resolution and the role of feedback control in dAFM. Prior efforts to analyze imaging resolution in dAFM have typically focused on the small-amplitude limit in order to establish a relationship between various noise sources in the experimental setup and the minimum detectable gradient of

• the tip–sample force [1][4][8][9]. However, the optimal imaging amplitude in FM has also been considered [10]. The role of feedback control in dAFM and its stability have been studied largely by using numerical simulations to solve complex systems of nonlinear, integro-differential equations governing

Probing three-dimensional surface force fields with atomic resolution: Measurement strategies, limitations, and artifact reduction

• Mehmet Z. Baykara,
• Omur E. Dagdeviren,
• Todd C. Schwendemann,
• Harry Mönig,
• Eric I. Altman and
• Udo D. Schwarz

Beilstein J. Nanotechnol. 2012, 3, 637–650, doi:10.3762/bjnano.3.73

• current, which is recorded together with the frequency-shift data, does not decay too fast to provide accurate calibration at all distances covered by the 3-D set. A completely different source of drift may originate from the use of analog electronics for oscillation detection and amplitude/phase-feedback

• control during NC-AFM operation. With such setups, the output voltage that is supposed to faithfully reflect the cantilever resonance frequency may shift over time even if the resonance frequency stays constant. If this happens, the data acquisition software interprets the shift as an apparent change in

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

• feedback control. A cantilever in contact has contact resonance modes [46] and the cantilever vibration amplitude is amplified at the contact resonance frequency, which increases with increasing surface stiffness. Contact resonances modes in air have been used to quantify the stiffness of surfaces [31

Drive-amplitude-modulation atomic force microscopy: From vacuum to liquids

• Miriam Jaafar,
• David Martínez-Martín,
• Mariano Cuenca,
• John Melcher,
• Arvind Raman and
• Julio Gómez-Herrero

Beilstein J. Nanotechnol. 2012, 3, 336–344, doi:10.3762/bjnano.3.38

• been extended to operate in other media with lower Q, with remarkable success [11]. However, FM-AFM has a well-known drawback: The transition from noncontact to contact causes an instability in the feedback control [12], which is particularly important for inhomogeneous surfaces in which, for example