Articles de revues : « AFM cantilever »

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Dannberg, Oliver, et Thomas Fröhlich. « Steifigkeitsmessungen von AFM-Cantilevern ». tm - Technisches Messen 88, s1 (24 août 2021) : s3—s7. http://dx.doi.org/10.1515/teme-2021-0046.

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Zusammenfassung Zur rückführbaren Kraftmessung mit AFM-Cantilevern ist aufgrund von Fertigungstoleranzen eine individuelle Kalibrierung jedes einzelnen Cantilevers notwendig. An der TU-Ilmenau wurde ein Prüfstand entwickelt, welcher die Steifigkeit nach einem statisch experimentellen Verfahren bestimmt. Dabei wird der Cantilever um einen definierten Weg ausgelenkt und die dazu notwendige Kraft gemessen. Die Wegmessung erfolgt durch ein kommerzielles Differenzinterferometer und die Kraftmessung mithilfe einer neu entwickelten Wägezelle. In diesem Artikel wird die Funktion des Prüfstandes am Beispiel einer Kalibrierung beschrieben und ein Messunsicherheitsbudget aufgestellt. Die relative Messunsicherheit beträgt ca. 1,5% bei einer maximalen Kalibrierkraft von <100 nN. Eine anschließende Untersuchung des Cantilevers ergab keine nachweisbaren Schäden an dessen Spitze.

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Slattery, Ashley D., Adam J. Blanch, Cameron J. Shearer, Andrew J. Stapleton, Renee V. Goreham, Sarah L. Harmer, Jamie S. Quinton et Christopher T. Gibson. « Characterisation of the Material and Mechanical Properties of Atomic Force Microscope Cantilevers with a Plan-View Trapezoidal Geometry ». Applied Sciences 9, n^o 13 (27 juin 2019) : 2604. http://dx.doi.org/10.3390/app9132604.

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Cantilever devices have found applications in numerous scientific fields and instruments, including the atomic force microscope (AFM), and as sensors to detect a wide range of chemical and biological species. The mechanical properties, in particular, the spring constant of these devices is crucial when quantifying adhesive forces, material properties of surfaces, and in determining deposited mass for sensing applications. A key component in the spring constant of a cantilever is the plan-view shape. In recent years, the trapezoidal plan-view shape has become available since it offers certain advantages to fast-scanning AFM and can improve sensor performance in fluid environments. Euler beam equations relating cantilever stiffness to the cantilever dimensions and Young’s modulus have been proven useful and are used extensively to model cantilever mechanical behaviour and calibrate the spring constant. In this work, we derive a simple correction factor to the Euler beam equation for a beam-shaped cantilever that is applicable to any cantilever with a trapezoidal plan-view shape. This correction factor is based upon previous analytical work and simplifies the application of the previous researchers formula. A correction factor to the spring constant of an AFM cantilever is also required to calculate the torque produced by the tip when it contacts the sample surface, which is also dependent on the plan-view shape. In this work, we also derive a simple expression for the torque for triangular plan-view shaped cantilevers and show that for the current generation of trapezoidal plan-view shaped AFM cantilevers, this will be a good approximation. We shall apply both these correction factors to determine Young’s modulus for a range of trapezoidal-shaped AFM cantilevers, which are specially designed for fast-scanning. These types of AFM probes are much smaller in size when compared to standard AFM probes. In the process of analysing the mechanical properties of these cantilevers, important insights are also gained into their spring constant calibration and dimensional factors that contribute to the variability in their spring constant.

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Zhao, Yu Wen, Yun Peng Song, Sen Wu et Xing Fu. « Accurate and Traceable Calibration of the Stiffness of Various AFM Cantilevers ». Key Engineering Materials 645-646 (mai 2015) : 817–23. http://dx.doi.org/10.4028/www.scientific.net/kem.645-646.817.

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Atomic force microscope (AFM) is widely used to measure nanoforce in the analysis of nanomechanical and biomechanical properties. As the critical factor in the nanoforce measurement, the stiffness of the AFM cantilever must be determined properly. In this paper, an accurate and SI-traceable calibration method is presented to obtain the stiffness of the AFM cantilever in the normal direction. The calibration system consists of a homemade AFM head and an ultra-precision electromagnetic balance. The calibration is based on the Hooke's law i.e. the stiffness is equal to the force divided by the deflection of the cantilever. With this system, three kinds of cantilevers were calibrated. The relative standard deviation is better than 1%. The results of these experiments showed good accuracy and repeatability.

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Cho, Ki Ho, Hak Joo Lee, Jae Hyun Kim, Jong Man Kim, Yong Kweon Kim et Chang Wook Baek. « A Study of Nano-Indentation Test Using Rhombus-Shaped Cantilever in Atomic Force Microscope ». Key Engineering Materials 326-328 (décembre 2006) : 207–10. http://dx.doi.org/10.4028/www.scientific.net/kem.326-328.207.

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We have designed and fabricated diamond-shaped AFM cantilevers capable of performing multi-functioning tasks by using single crystal silicon (SCS) micromachining techniques. Structural improvement of the cantilever has clearly solved the crucial problems resulted from using conventional simple beam-AFM cantilever for mechanical testing. After forcecalibration of the cantilever, indentation tests are performed to determine the mechanical behaviors in micro/nano-scale as well as topographic imaging. A diamond Berkovich tip of which radius at the apex is approximately 20 nm is attached on the cantilever for the indentation test and 3D topography measurement. The indentation load-depth curves of nano-scale polymeric pattern (PAK01-UV curable blended resin) are measured and surface topography right after indenting is also obtained. Development of this novel cantilever will extend the AFM functionality into the highly sensitive mechanical testing devices in nano/pico scale.

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Dat, Le Tri, Ho Thanh Huy et Nguyen Duy Vy. « A Theoretical Study of Deflection of AFM Bimaterial Cantilevers Versus Irradiated Position ». Communications in Physics 28, n^o 3 (14 novembre 2018) : 255. http://dx.doi.org/10.15625/0868-3166/28/3/12673.

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The bimaterial cantilevers of atomic force microscopes have been widely used in chemical and bio-sensing. Due to the difference in the thermal expansion coefficients of the two layers, the cantilever is deflected and its deflections is dependent on the heat absorption from the ambient environment or the objects adsorbed on the cantilever surface. In this study, we theoretically examine the deflection of this cantilever considering different irradiated configurations of a laser beam and thicknesses of the coating layer. We show that the temperature difference between the end and the clamped position is maximized for an irradiation at the cantilever end and this difference reduces with increasing coating thickness. Especially, the maximal deflection is seen for an irradiation in the middle of the cantilever, around 0.6 of the cantilever length from the clamped position. The obtained results could help determining an irradiated configuration of laser and the coating thickness to optimize the sensitivity of the cantilevers in thermally sensing devices.

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Boubekri, Rachida, Edmond Cambril, L. Couraud, Lorenzo Bernardi, Ali Madouri, David Martrou et Sébastien Gauthier. « High Frequency 3C-SiC AFM Cantilever Using Thermal Actuation and Metallic Piezoresistive Detection ». Materials Science Forum 711 (janvier 2012) : 80–83. http://dx.doi.org/10.4028/www.scientific.net/msf.711.80.

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One way to improve the force sensitivity of Atomic Force Microscopy (AFM) cantilevers is to increase their resonance frequency. SiC is an excellent material for that purpose due to its high Young’s modulus and low mass density. This size reduction makes conventional optical motion detection methods inappropriate. Here, we introduce self-sensing, self-excited high frequency AFM cantilevers. The motion detection is based on the measurement of a metallic piezoresistor incorporated in the cantilever. The motion excitation is performed by electrothermal actuation using another metallic circuit. Cantilevers with sizes as low as 4 μm in length, 1.2 μm in width and 0.5 μm in thickness were realized by using different steps of e-beam lithography, deposition of thin gold films to pattern the piezoresistor and the electrothermal actuation electrode. Dry etching SF6plasma was used for etching the SiC cantilever and TMAH solution heated to 80°C to release the cantilever. In this case, a thigh control of underetching, which reduces the cantilever resonance frequency was required.

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Mordue, Christopher W., Jonathan M. R. Weaver et Phillip S. Dobson. « Thermal induced deflection in atomic force microscopy cantilevers : analysis & ; solution ». Measurement Science and Technology 34, n^o 12 (25 août 2023) : 125013. http://dx.doi.org/10.1088/1361-6501/acf061.

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Abstract Atomic force microscopy (AFM) cantilevers are commonly made from two material layers: a reflective coating and structural substrate. Although effective, this can result in thermally induced cantilever deflection due to ambient and local temperature changes. While this has been previously documented, key aspects of this common phenomenon have been overlooked. This work explores the impact of thermally induced cantilever deflection when in- and out-of-contact, including the topographic scan artefacts produced. Scanning thermal microscopy probes were employed to provide direct cantilever temperature measurement from Peltier and microheater sources, whilst permitting cantilever deflection to be simultaneously monitored. Optical lever-based measurements of thermal deflection in the AFM were found to vary by up to 250% depending on the reflected laser spot location on the cantilever. This highlights AFM’s inherent inability to correctly measure and account for thermal induced cantilever deflection in its feedback system. This is particularly problematic when scanning a tip in-contact with the surface, when probe behaviour is closer mechanically to that of a bridge than a cantilever regarding thermal bending. In this case, measurements of cantilever deflection and inferred surface topography contained significant artefacts and varied from negative to positive for different optical lever laser locations on the cantilevers. These topographic errors were measured to be up to 600 nm for a small temperature change of 2 K. However, all cantilevers measured showed a point of consistent, complete thermal deflection insensitivity 55% to 60% along their lengths. Positioning the reflected laser at this location, AFM scans exhibited improvements of up-to 97% in thermal topographic artefacts relative to other laser positions.

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Damircheli, Mehrnoosh, et Babak Eslami. « Design of V-shaped cantilevers for enhanced multifrequency AFM measurements ». Beilstein Journal of Nanotechnology 11 (6 octobre 2020) : 1525–41. http://dx.doi.org/10.3762/bjnano.11.135.

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As the application of atomic force microscopy (AFM) in soft matter characterization has expanded, the use of different types of cantilevers for these studies have also increased. One of the most common types of cantilevers used in soft matter imaging is V-shaped cantilevers due to their low normal spring constant. These types of cantilevers are also suitable for nanomanipulation due to their high lateral spring constants. The combination of low normal spring constant and high lateral spring constants makes V-shaped cantilevers promising candidates for imaging soft matter. Although these cantilevers are widely used in the field, there are no studies on the static and dynamic behavior of V-shaped cantilevers in multifrequency AFM due to their complex geometry. In this work, the static and dynamic properties of V-shaped cantilevers are studied while investigating their performance in multifrequency AFM (specifically bimodal AFM). By modeling the cantilevers based on Timoshenko beam theory, the geometrical dimensions such as length, base width, leg width and thickness are studied. By finding the static properties (mass, spring constants) and dynamic properties (resonance frequencies and quality factors) for different geometrical dimensions, the optimum V-shaped cantilever that can provide the maximum phase contrast in bimodal AFM between gold (Au) and polystyrene (PS) is found. Based on this study, it is found that as the length of the cantilever increases the 2nd eigenmode phase contrast decreases. However, the base width exhibits the opposite relationship. It is also found that the leg width does not have a monotone relationship similar to length and base width. The phase contrast increases for the range of 14 to 32 µm but decreases afterwards. The thickness of a V-shaped cantilever does not play a major role in defining the dynamics of the cantilever compared to other parameters. This work shows that in order to maximize the phase contrast, the ratio of second to first eigenmode frequencies should be minimized and be close to a whole number. Additionally, since V-shaped cantilevers are mostly used for soft matter imaging, lower frequency ratios dictate lower spring constant ratios, which can be advantageous due to lower forces applied to the surface by the tip given a sufficiently high first eigenmode frequency. Finally, two commercially available V-shaped cantilevers are theoretically and experimentally benchmarked with an optimum rectangular cantilever. Two sets of bimodal AFM experiments are carried out on Au-PS and PS-LDPE (polystyrene and low-density polyethylene) samples to verify the simulation results.

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Liu, Hao, Zuned Ahmed, Sasa Vranjkovic, Manfred Parschau, Andrada-Oana Mandru et Hans J. Hug. « A cantilever-based, ultrahigh-vacuum, low-temperature scanning probe instrument for multidimensional scanning force microscopy ». Beilstein Journal of Nanotechnology 13 (11 octobre 2022) : 1120–40. http://dx.doi.org/10.3762/bjnano.13.95.

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Cantilever-based atomic force microscopy (AFM) performed under ambient conditions has become an important tool to characterize new material systems as well as devices. Current instruments permit robust scanning over large areas, atomic-scale lateral resolution, and the characterization of various sample properties using multifrequency and multimodal AFM operation modes. Research of new quantum materials and devices, however, often requires low temperatures and ultrahigh vacuum (UHV) conditions and, more specifically, AFM instrumentation providing atomic resolution. For this, AFM instrumentation based on a tuning fork force sensor became increasingly popular. In comparison to microfabricated cantilevers, the more macroscopic tuning forks, however, lack sensitivity, which limits the measurement bandwidth. Moreover, multimodal and multifrequency techniques, such as those available in cantilever-based AFM carried out under ambient conditions, are challenging to implement. In this article, we describe a cantilever-based low-temperature UHV AFM setup that allows one to transfer the versatile AFM techniques developed for ambient conditions to UHV and low-temperature conditions. We demonstrate that such a cantilever-based AFM offers experimental flexibility by permitting multimodal or multifrequency operations with superior force derivative sensitivities and bandwidths. Our instrument has a sub-picometer gap stability and can simultaneously map not only vertical and lateral forces with atomic-scale resolution, but also perform rapid overview scans with the tip kept at larger tip–sample distances for robust imaging.

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Yeh, Meng Kao, Bo Yi Chen, Nyan Hwa Tai et Chien Chao Chiu. « Force Measurement by AFM Cantilever with Different Coating Layers ». Key Engineering Materials 326-328 (décembre 2006) : 377–80. http://dx.doi.org/10.4028/www.scientific.net/kem.326-328.377.

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Atomic force microscopy (AFM) is widely used in many fields, because of its outstanding force measurement ability in nano scale. Some coating layers are used to enhance the signal intensity, but these coating layers affect the spring constant of AFM cantilever and the accuracy of force measurement. In this paper, the spring constants of rectangular cantilever with different coating thickness were quantitatively measured and discussed. The finite element method was used to analyze the nonlinear force-displacement behavior from which the cantilever’s normal and torsional spring constants could be determined. The experimental data and the numerical results were also compared with the results from other methods. By considering the influence of coating layers and real cantilever geometries, the more accurate force measurements by AFM cantilever can be obtained.

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KWEON, HYUNKYU, et KIHO NAM. « MEASUREMENT OF AFM CANTILEVER SPRING CONSTANT BY USING THE SURFACE PROFILE ». International Journal of Modern Physics B 24, n^o 18 (20 juillet 2010) : 3597–606. http://dx.doi.org/10.1142/s0217979210054865.

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This study introduces a new method of measuring the stiffness (spring constant) of cantilevers that is designed to improve the measurement accuracy of (atomic force microscopy) (AFM). AFM cantilever spring constants are determined by the relation between the slope of the step height ascertained from the surface profile measurement results, and the size of the cantilever. The surface profile measurements of the standard specimens with three different step heights (height: 100, 500, and 1000 nm) were conducted using a standard cantilever with different stiffness. As a result of this exercise, the profile slope was found to be proportional to cantilever stiffness, and the necessity was uncovered to conduct a similar experiment in order to clarify the quantitative relation between stiffness and the profile slope when the same kind of cantilever is utilized.

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Moore, Steven Ian, Michael G. Ruppert et Yuen Kuan Yong. « Multimodal cantilevers with novel piezoelectric layer topology for sensitivity enhancement ». Beilstein Journal of Nanotechnology 8 (6 février 2017) : 358–71. http://dx.doi.org/10.3762/bjnano.8.38.

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Self-sensing techniques for atomic force microscope (AFM) cantilevers have several advantageous characteristics compared to the optical beam deflection method. The possibility of down scaling, parallelization of cantilever arrays and the absence of optical interference associated imaging artifacts have led to an increased research interest in these methods. However, for multifrequency AFM, the optimization of the transducer layout on the cantilever for higher order modes has not been addressed. To fully utilize an integrated piezoelectric transducer, this work alters the layout of the piezoelectric layer to maximize both the deflection of the cantilever and measured piezoelectric charge response for a given mode with respect to the spatial distribution of the strain. On a prototype cantilever design, significant increases in actuator and sensor sensitivities were achieved for the first four modes without any substantial increase in sensor noise. The transduction mechanism is specifically targeted at multifrequency AFM and has the potential to provide higher resolution imaging on higher order modes.

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Korayem, M. H., M. Taheri et S. D. Ghahnaviyeh. « Sobol method application in dimensional sensitivity analyses of different AFM cantilevers for biological particles ». Modern Physics Letters B 29, n^o 22 (20 août 2015) : 1550123. http://dx.doi.org/10.1142/s0217984915501237.

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Due to the more delicate nature of biological micro/nanoparticles, it is necessary to compute the critical force of manipulation. The modeling and simulation of reactions and nanomanipulator dynamics in a precise manipulation process require an exact modeling of cantilevers stiffness, especially the stiffness of dagger cantilevers because the previous model is not useful for this investigation. The stiffness values for V-shaped cantilevers can be obtained through several methods. One of them is the PBA method. In another approach, the cantilever is divided into two sections: a triangular head section and two slanted rectangular beams. Then, deformations along different directions are computed and used to obtain the stiffness values in different directions. The stiffness formulations of dagger cantilever are needed for this sensitivity analyses so the formulations have been driven first and then sensitivity analyses has been started. In examining the stiffness of the dagger-shaped cantilever, the micro-beam has been divided into two triangular and rectangular sections and by computing the displacements along different directions and using the existing relations, the stiffness values for dagger cantilever have been obtained. In this paper, after investigating the stiffness of common types of cantilevers, Sobol sensitivity analyses of the effects of various geometric parameters on the stiffness of these types of cantilevers have been carried out. Also, the effects of different cantilevers on the dynamic behavior of nanoparticles have been studied and the dagger-shaped cantilever has been deemed more suitable for the manipulation of biological particles.

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Ageev, Oleg A., Oleg I. Ilin, Alexei S. Kolomiytsev, Sergey A. Lisitsyn, Vladimir A. Smirnov et Evgeny G. Zamburg. « Formation of High Aspect Ratio Nanostructures Using Focused Ion Beam Induced Deposition of Carbon ». Applied Mechanics and Materials 752-753 (avril 2015) : 154–58. http://dx.doi.org/10.4028/www.scientific.net/amm.752-753.154.

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This paper presents results of the formation of high aspect nanostructures by local deposition of carbon, stimulated by focused ion beam (FIB). The structures used in the modification of the probe sensors were cantilevers for atomic force microscopy (AFM). The FIB structure of 5 mm length and 50 mm radius of curvature formed on the surface of the cantilever tip has shown to improve the accuracy of measurement by AFM. The outcome of this study is useful for the development of manufacturing processes and modification of the probe sensor-cantilever AFM structures of field-electron emitters as well as in the studies of micro- and nanosystems technology.

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Mishra, Rohit, Wilfried Grange et Martin Hegner. « Rapid and Reliable Calibration of Laser Beam Deflection System for Microcantilever-Based Sensor Setups ». Journal of Sensors 2012 (2012) : 1–6. http://dx.doi.org/10.1155/2012/617386.

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Cantilever array-based sensor devices widely utilise the laser-based optical deflection method for measuring static cantilever deflections mostly with home-built devices with individual geometries. In contrast to scanning probe microscopes, cantilever array devices have no additional positioning device like a piezo stage. As the cantilevers are used in more and more sensitive measurements, it is important to have a simple, rapid, and reliable calibration relating the deflection of the cantilever to the change in position measured by the position-sensitive detector. We present here a simple method for calibrating such systems utilising commercially available AFM cantilevers and the equipartition theorem.

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Dzedzickis, Andrius, Justė Rožėnė, Vytautas Bučinskas, Darius Viržonis et Inga Morkvėnaitė-Vilkončienė. « Characteristics and Functionality of Cantilevers and Scanners in Atomic Force Microscopy ». Materials 16, n^o 19 (24 septembre 2023) : 6379. http://dx.doi.org/10.3390/ma16196379.

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In this paper, we provide a systematic review of atomic force microscopy (AFM), a fast-developing technique that embraces scanners, controllers, and cantilevers. The main objectives of this review are to analyze the available technical solutions of AFM, including the limitations and problems. The main questions the review addresses are the problems of working in contact, noncontact, and tapping AFM modes. We do not include applications of AFM but rather the design of different parts and operation modes. Since the main part of AFM is the cantilever, we focused on its operation and design. Information from scientific articles published over the last 5 years is provided. Many articles in this period disclose minor amendments in the mechanical system but suggest innovative AFM control and imaging algorithms. Some of them are based on artificial intelligence. During operation, control of cantilever dynamic characteristics can be achieved by magnetic field, electrostatic, or aerodynamic forces.

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Liang, Li-Na, Liao-Liang Ke, Yue-Sheng Wang, Jie Yang et Sritawat Kitipornchai. « Flexural Vibration of an Atomic Force Microscope Cantilever Based on Modified Couple Stress Theory ». International Journal of Structural Stability and Dynamics 15, n^o 07 (31 août 2015) : 1540025. http://dx.doi.org/10.1142/s0219455415400258.

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This paper is concerned with the flexural vibration of an atomic force microscope (AFM) cantilever. The cantilever problem is formulated on the basis of the modified couple stress theory and the Timoshenko beam theory. The modified couple stress theory is a nonclassical continuum theory that includes one additional material parameter to describe the size effect. By using the Hamilton's principle, the governing equation of motion and the boundary conditions are derived for the AFM cantilevers. The equation is solved using the differential quadrature method for the natural frequencies and mode shapes. The effects of the sample surface contact stiffness, length scale parameter and location of the sensor tip on the flexural vibration characteristics of AFM cantilevers are discussed. Results show that the size effect on the frequency is significant when the thickness of the microcantilever has a similar value to the material length scale parameter.

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Ghatkesar, Murali Krishna, Hector Hugo Perez Garza et Urs Staufer. « Hollow AFM cantilever pipette ». Microelectronic Engineering 124 (juillet 2014) : 22–25. http://dx.doi.org/10.1016/j.mee.2014.04.019.

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Hosseini, Nahid, Matthias Neuenschwander, Oliver Peric, Santiago H. Andany, Jonathan D. Adams et Georg E. Fantner. « Integration of sharp silicon nitride tips into high-speed SU8 cantilevers in a batch fabrication process ». Beilstein Journal of Nanotechnology 10 (29 novembre 2019) : 2357–63. http://dx.doi.org/10.3762/bjnano.10.226.

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Employing polymer cantilevers has shown to outperform using their silicon or silicon nitride analogues concerning the imaging speed of atomic force microscopy (AFM) in tapping mode (intermittent contact mode with amplitude modulation) by up to one order of magnitude. However, tips of the cantilever made out of a polymer material do not meet the requirements for tip sharpness and durability. Combining the high imaging bandwidth of polymer cantilevers with making sharp and wear-resistant tips is essential for a future adoption of polymer cantilevers in routine AFM use. In this work, we have developed a batch fabrication process to integrate silicon nitride tips with an average tip radius of 9 ± 2 nm into high-speed SU8 cantilevers. Key aspects of the process are the mechanical anchoring of a moulded silicon nitride tip and a two-step release process. The fabrication recipe can be adjusted to any photo-processable polymer cantilever.

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Ganser, Christian, Gerhard Fritz-Popovski, Roland Morak, Parvin Sharifi, Benedetta Marmiroli, Barbara Sartori, Heinz Amenitsch, Thomas Griesser, Christian Teichert et Oskar Paris. « Cantilever bending based on humidity-actuated mesoporous silica/silicon bilayers ». Beilstein Journal of Nanotechnology 7 (28 avril 2016) : 637–44. http://dx.doi.org/10.3762/bjnano.7.56.

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We use a soft templating approach in combination with evaporation induced self-assembly to prepare mesoporous films containing cylindrical pores with elliptical cross-section on an ordered pore lattice. The film is deposited on silicon-based commercial atomic force microscope (AFM) cantilevers using dip coating. This bilayer cantilever is mounted in a humidity controlled AFM, and its deflection is measured as a function of relative humidity. We also investigate a similar film on bulk silicon substrate using grazing-incidence small-angle X-ray scattering (GISAXS), in order to determine nanostructural parameters of the film as well as the water-sorption-induced deformation of the ordered mesopore lattice. The strain of the mesoporous layer is related to the cantilever deflection using simple bilayer bending theory. We also develop a simple quantitative model for cantilever deflection which only requires cantilever geometry and nanostructural parameters of the porous layer as input parameters.

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Sone, Hayato, Shoichi Ichikawa, Yuji Matsubara, Mitsumasa Suzuki, Haruki Okano, Takashi Izumi et Sumio Hosaka. « Prototype of Frame-Type Cantilever for Biosensor and Femtogram Detection ». Key Engineering Materials 459 (décembre 2010) : 134–39. http://dx.doi.org/10.4028/www.scientific.net/kem.459.134.

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The possibility of realizing femtogram mass detection using a frame-type microcantilever has been studied in bioscience. To realize highly sensitive mass detection by reducing the viscose resistance in liquids, we designed frame-type cantilevers using finite element modeling (FEM). We fabricated prototypes of mesh-type, hole-type and conventional-type cantilevers using a semiconductor process. The properties of the cantilevers were measured by a conventional atomic force microscope (AFM) system. The measured resonance frequencies of the cantilevers were almost consistent with the calculated results of the FEM simulation in air. The resonance frequency and quality (Q) factor of the mesh-type cantilever were larger than those of the conventional-type cantilever in water. We measured the frequency change due to gold film deposition on the mesh-type cantilever. Then, we estimated the mass sensitivity of the cantilever at about 16.6 fg/Hz. This value is more than 10 times smaller than that of the conventional-type cantilever. These results indicate that the mesh-type cantilever has the advantage of reducing the viscous resistance and achieving high sensitivity in liquids.

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Lee, Hak Joo, Ki Ho Cho, Jae Hyun Kim, Seung Woo Han, Byung Ik Choi, Chang Wook Baek, Jong Man Kim et Sung Hoon Choa. « Force-Calibrated AFM for Mechanical Test of Freestanding Thin Films ». Key Engineering Materials 297-300 (novembre 2005) : 275–79. http://dx.doi.org/10.4028/www.scientific.net/kem.297-300.275.

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Atomic force microscope (AFM) is a powerful tool for exploring a nano-scale world. It can measure a nano-scale surface topography with very high resolution and detect a very small force. In this paper, we propose a novel AFM cantilever and its calibration scheme to utilize AFM as a mechanical testing machine. We call this AFM with a new cantilever as a force-calibrated AFM. The feasibility of the AFM cantilever is validated through measurement of mechanical properties of freestanding Au thin films.

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Magonov, Sergei. « High-Resolution Imaging with Atomic Force Microscopy ». Microscopy Today 12, n^o 5 (septembre 2004) : 12–15. http://dx.doi.org/10.1017/s1551929500056248.

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The invention of scanning tunneling microscopy (STM) in 1982 revolutionized surface analysis by providing atomic-scale surface imaging of conducting and semiconducting materials. Shortly after that, atomic force microscopy (AFM) was introduced as an accessory of STM for high-resolution imaging of surfaces independent of their conductivity. Mechanical force interactions between a sharp tip placed at one end of a micro fabricated cantilever and a sample surface were employed for imaging in this method. In the past decade, AFM has developed into a leading scanning probe technique applied in many fields of fundamental and industrial research. The progress of AFM has been made possible by implementation of an optical level detection scheme, which allows precise measuring of the cantilever deflection caused by the tip-sample forces, by mass microfabrication of probes consisting of cantilevers, and by developments of oscillatory imaging modes, particularly, Tapping ModeTM.

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LEE, HAK-JOO, JAE-HYUN KIM, KIHO CHO, JAE-YOON KANG, CHANG-WOOK BAEK, JONG-MAN KIM et SUNG-HOON CHOA. « SYMMETRIC AFM CANTILEVER FOR MECHANICAL CHARACTERIZATION OF Mo THIN FILM ». International Journal of Modern Physics B 20, n^o 25n27 (30 octobre 2006) : 3781–86. http://dx.doi.org/10.1142/s0217979206040362.

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We have developed a novel method and device for measuring the mechanical properties of micro/nano structures. An atomic force microscope (AFM) was employed to sense applied force and displacement and a new AFM cantilever which overcame the critical problems associated with conventional AFM cantilever systems was fabricated using single crystal silicon (110). The symmetrically designed cantilever removed lateral motion of the probe during indentation and strip bending tests. Strip bending tests on fixed-fixed molybdenum ( Mo ) strips 1 μm in thickness using the assembled cantilever in AFM system showed that consistent load-displacement curves can be obtained. The effect of adhesive energy on mechanical tests in micro/nano-scale was revealed.

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Cha, Wujoon, Matthew F. Campbell, Akshat Jain et Igor Bargatin. « Hollow AFM Cantilever with Holes ». Engineering Proceedings 4, n^o 1 (14 avril 2021) : 13. http://dx.doi.org/10.3390/micromachines2021-09544.

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Tang, Chen Zhi. « A Method to Fabricate Thin Micro Silicon Cantilever Based on Optical Lithography with AZ 1518 ». Key Engineering Materials 645-646 (mai 2015) : 1093–98. http://dx.doi.org/10.4028/www.scientific.net/kem.645-646.1093.

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AZ 1518 is a standard thin positive photoresist in AZ1500series which has been widely used in photolithography process, beside this, as a perfect semiconductor material, micro sized silicon cantilevers have been widely used in micro electromechanical systems (MEMS). In This paper, we have presented the process of fabricate micro silicon cantilever, including the selection of the photoresist, developer and substrate, optical lithography method and PLD method. After these, AFM is used to study the cantilever pattern and the angle of inclined planes. The research results show the exposure time and experimental environment can significantly influent the quality of cantilever pattern.

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Schumacher, Zeno, Yoichi Miyahara, Laure Aeschimann et Peter Grütter. « Improved atomic force microscopy cantilever performance by partial reflective coating ». Beilstein Journal of Nanotechnology 6 (3 juillet 2015) : 1450–56. http://dx.doi.org/10.3762/bjnano.6.150.

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Optical beam deflection systems are widely used in cantilever based atomic force microscopy (AFM). Most commercial cantilevers have a reflective metal coating on the detector side to increase the reflectivity in order to achieve a high signal on the photodiode. Although the reflective coating is usually much thinner than the cantilever, it can still significantly contribute to the damping of the cantilever, leading to a lower mechanical quality factor (Q-factor). In dynamic mode operation in high vacuum, a cantilever with a high Q-factor is desired in order to achieve a lower minimal detectable force. The reflective coating can also increase the low-frequency force noise. In contact mode and force spectroscopy, a cantilever with minimal low-frequency force noise is desirable. We present a study on cantilevers with a partial reflective coating on the detector side. For this study, soft (≈0.01 N/m) and stiff (≈28 N/m) rectangular cantilevers were used with a custom partial coating at the tip end of the cantilever. The Q-factor, the detection and the force noise of fully coated, partially coated and uncoated cantilevers are compared and force distance curves are shown. Our results show an improvement in low-frequency force noise and increased Q-factor for the partially coated cantilevers compared to fully coated ones while maintaining the same reflectivity, therefore making it possible to combine the best of both worlds.

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Grigoriadis, Kyriakos, Alexandros Palaiologos, Anastasios Zavos et Pantelis G. Nikolakopoulos. « A Tribological Simulation for a Typical Carbon Coated AFM Cantilever Interacting with a Monolayer Graphene Sheet ». MATEC Web of Conferences 188 (2018) : 01029. http://dx.doi.org/10.1051/matecconf/201818801029.

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This study aims on the dynamic and tribological characterization of a Single Layer Graphene Sheet (SLGS) including the effects of a graphene cantilever’s deflection. A 10 x 10 nm graphene model is developed, which is modally analyzed for both Zigzag and Armchair lattices. A typical Atomic Force Microscope (AFM) cantilever with carbon coated tip is also modeled during the simulation. The friction forces applied on the tip during its movement can be evaluated. The real contact area is characterized as the carbon atom tip is interlinked with the graphene atoms via the Lennard-Jones model. This study confirmed that the deformation of the AFM cantilever, is important to predict more accurately the tribological behaviour of graphene and the effect of its lattice orientation to its frictional properties. Therefore, this simulation provides an interesting way to understand the complex interaction between the cantilever tip and the sample in different contact conditions.

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Giessibl, Franz. « Probing the Nature of Chemical Bonds by Atomic Force Microscopy ». Molecules 26, n^o 13 (3 juillet 2021) : 4068. http://dx.doi.org/10.3390/molecules26134068.

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The nature of the chemical bond is important in all natural sciences, ranging from biology to chemistry, physics and materials science. The atomic force microscope (AFM) allows to put a single chemical bond on the test bench, probing its strength and angular dependence. We review experimental AFM data, covering precise studies of van-der-Waals-, covalent-, ionic-, metallic- and hydrogen bonds as well as bonds between artificial and natural atoms. Further, we discuss some of the density functional theory calculations that are related to the experimental studies of the chemical bonds. A description of frequency modulation AFM, the most precise AFM method, discusses some of the experimental challenges in measuring bonding forces. In frequency modulation AFM, forces between the tip of an oscillating cantilever change its frequency. Initially, cantilevers were made mainly from silicon. Most of the high precision measurements of bonding strengths by AFM became possible with a technology transfer from the quartz watch technology to AFM by using quartz-based cantilevers (“qPlus force sensors”), briefly described here.

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Zauscher, Stefan. « Putting a Sphere on an Atomic Force Microscope Cantilever Tip ». Microscopy Today 5, n^o 10 (décembre 1997) : 6. http://dx.doi.org/10.1017/s155192950006065x.

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Atomic Force Microscopes (AFM) can measure the force between a surface and the tip of a cantilever as a junction of separation with great precision. For example, van der Waals type forces and electrostatic repulsive forces can easily be measured in aqueous solutions using an AFM. The complex, pyramidal shape of the typical AFM cantilever is, however, not well suited for quantitative measurements. It is thus desirable to attach particles of known geometry (usually spheres) to the tip of a cantilever.

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Tortonese, M., et F. J. Giessibl. « Atomic-Force Microscopy with piezoresistive cantilevers ». Proceedings, annual meeting, Electron Microscopy Society of America 52 (1994) : 1064–65. http://dx.doi.org/10.1017/s0424820100173054.

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The atomic force microscope (AFM) works by measuring the deflection of a cantilever as it is scanned over a sample. A sharp tip at the end of the cantilever is responsible for the high lateral resolution achieved with the AFM. There are several ways to measure the deflection of the cantilever. The technique used to measure the deflection of the cantilever most often dictates the mechanical complexity and stability of the instrument. Electron tunneling, interferometry and capacitive sensors have been used successfully. The most common way to measure the cantilever deflection is by means of an optical deflection detector.The piezoresistivc cantilever offers a new way to measure the deflection of the cantilever, with performances comparable to the performances of other deflection detectors, and with the advantage that the sensor is incorporated in the cantilever. This simplifies the design and operation of the microscope In particular, the piezoresistive cantilever facilitates the use and often improves the performances of an AFM when operated in ultra high vacuum (UHV), at low temperature, or when used to image large samples.

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Cleveland, Jason. « Anomalous Changes in Tip Height in Tapping AFM ». Microscopy Today 8, n^o 4 (mai 2000) : 36–37. http://dx.doi.org/10.1017/s155192950006346x.

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This effect can be understood by considering what happens to the cantilever and tip as the base of the vibrating cantilever is brought closer to the sample (like in a force curve). When the vibrating cantilever first approaches the surface, the tip senses attractive forces. In standard imaging conditions, these are usually due to meniscus forces between a layer of adsorbed liquid (often water) on the surface of the sample and the tip. However, even in clean conditions, other attractive forces like Van der Waals will generally be present. These attractive forces move the resonance of the cantilever downward in frequency. Since the cantilever is being driven at the original resonance frequency of the cantilever, this will cause the cantilever amplitude to decrease as the attractive forces puli the resonance peak out from under the drive frequency. This decrease is often quite linear with distance, but doesn't have to be. In this case the tip is actually turning around some distance (this could typically be a few nanometers) before it touches the surface. This regime is commonly called the “attractive” regime because attractive forces dominate the behavior of the cantilever.

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Ficek, Mateusz, Maciej J. Głowacki, Krzysztof Gajewski, Piotr Kunicki, Ewelina Gacka, Krystian Sycz, Mariusz Mrózek et al. « Integration of Fluorescent, NV-Rich Nanodiamond Particles with AFM Cantilevers by Focused Ion Beam for Hybrid Optical and Micromechanical Devices ». Coatings 11, n^o 11 (29 octobre 2021) : 1332. http://dx.doi.org/10.3390/coatings11111332.

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In this paper, a novel fabrication technology of atomic force microscopy (AFM) probes integrating cantilever tips with an NV-rich diamond particle is presented. Nanomanipulation techniques combined with the focused electron beam-induced deposition (FEBID) procedure were applied to position the NV-rich diamond particle on an AFM cantilever tip. Ultrasonic treatment of nanodiamond suspension was applied to reduce the size of diamond particles for proper geometry and symmetry. The fabricated AFM probes were tested utilizing measurements of the electrical resistance at highly oriented pyrolytic graphite (HOPG) and compared with a standard AFM cantilever performance. The results showed novel perspectives arising from combining the functionalities of a scanning AFM with optically detected magnetic resonance (ODMR). In particular, it offers enhanced magnetometric sensitivity and the nanometric resolution.

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Dillon, Eoghan, Kevin Kjoller et Craig Prater. « Lorentz Contact Resonance Imaging for Atomic Force Microscopes : Probing Mechanical and Thermal Properties on the Nanoscale ». Microscopy Today 21, n^o 6 (novembre 2013) : 18–24. http://dx.doi.org/10.1017/s1551929513000989.

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Atomic force microscopy (AFM) has been widely used in both industry and academia for imaging the surface topography of a material with nanoscale resolution. However, often little other information is obtained. Contact resonance AFM (CR-AFM) is a technique that can provide information about the viscoelastic properties of a material in contact with an AFM probe by measuring the contact stiffness between the probe and sample. In CR-AFM, an AFM cantilever is oscillated, and the amplitude and frequency of the resonance modes of the cantilever are monitored. When a probe or sample is oscillated, the tip sample interaction can be approximated as an ideal spring-dashpot system using the Voigt-Kelvin model shown in Figure 1. Contact resonance frequencies of the AFM cantilever will shift depending on the contact stiffness, k, between the tip and sample. The damping effect on the system comes from dissipative tip sample forces such as viscosity and adhesion. Damping, η, is observed in a CR-AFM system by monitoring the amplitude and Q factor of the resonant modes of the cantilever. This contact stiffness and damping information can then be used to obtain information about the viscoelastic properties of the material when fit to an applicable model.

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Lopez-Ayon, G. Monserratt, David J. Oliver, Peter H. Grutter et Svetlana V. Komarova. « Deconvolution of Calcium Fluorescent Indicator Signal from AFM Cantilever Reflection ». Microscopy and Microanalysis 18, n^o 4 (30 juillet 2012) : 808–15. http://dx.doi.org/10.1017/s1431927612000402.

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AbstractAtomic force microscopy (AFM) can be combined with fluorescence microscopy to measure the changes in intracellular calcium levels (indicated by fluorescence of Ca2+ sensitive dye fluo-4) in response to mechanical stimulation performed by AFM. Mechanical stimulation using AFM is associated with cantilever movement, which may interfere with the fluorescence signal. The motion of the AFM cantilever with respect to the sample resulted in changes of the reflection of light back to the sample and a subsequent variation in the fluorescence intensity, which was not related to changes in intracellular Ca2+ levels. When global Ca2+ responses to a single stimulation were assessed, the interference of reflected light with the fluorescent signal was minimal. However, in experiments where local repetitive stimulations were performed, reflection artifacts, correlated with cantilever motion, represented a significant component of the fluorescent signal. We developed a protocol to correct the fluorescence traces for reflection artifacts, as well as photobleaching. An added benefit of our method is that the cantilever reflection in the fluorescence recordings can be used for precise temporal correlation of the AFM and fluorescence measurements.

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Wu, Jianhua, Ying Fang, Dong Yang et Cheng Zhu. « Thermo-Mechanical Responses of a Surface-Coupled AFM Cantilever ». Journal of Biomechanical Engineering 127, n^o 7 (15 août 2005) : 1208–15. http://dx.doi.org/10.1115/1.2073647.

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Atomic force microscopy (AFM) has been widely used for measuring mechanical properties of biological specimens such as cells, DNA, and proteins. This is usually done by monitoring deformations in response to controlled applied forces, which have to be at ultralow levels due to the extreme softness of the specimens. Consequently, such experiments may be susceptible to thermal excitations, manifested as force and displacement fluctuations that could reduce the measurement accuracy. To take advantage of, rather than to be limited by, such fluctuations, we have characterized the thermomechanical responses of an arbitrarily shaped AFM cantilever with the tip coupled to an elastic spring. Our analysis shows that the cantilever and the specimen behave as springs in parallel. This provides a method for determining the elasticity of the specimen by measuring the change in the tip fluctuations in the presence and absence of coupling. For rectangular and V-shaped cantilevers, we have derived a relationship between the mean-square deflection and the mean-square inclination and an approximate expression for the specimen spring constant in terms of contributions to the mean-square inclination from the first few vibration modes.

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Zhang, Gai Mei, Li Ping Yang, Chen Qiang, Yuan Wei, Jian Dong Lu et Dong Sheng Jiang. « Analysis on the Contact Mechanics between Tip and Sample in Atomic Force Acoustic Microscope Method ». Advanced Materials Research 800 (septembre 2013) : 325–29. http://dx.doi.org/10.4028/www.scientific.net/amr.800.325.

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Atomic force acoustic microscopy (AFAM) is a technique combining the atomic force microscope (AFM) and ultrasonic technique, where the cantilever or the sample surface is vibrated at ultrasonic frequencies while a sample surface is scanned with the sensor tip contacting the sample. At a consequence, the amplitude of the cantilever vibration as well as the shift of the cantilever resonance frequencies contain information about local tip-sample contact stiffness and can be used as imaging quantities. It has been demonstrated to be a powerful tool for the investigation of the local elastic prosperities of sample surface. The sample is tested in the contact mode, the resonant frequency of the cantilever is measured, by which the contact stiffness is calculated based on the model of vibration of the cantilever, and then the elastic property of sample is evaluated according to the contact theory. Therefore, the contact model has an important impact on the calculation of elastic modulus. This paper analyzes the contact model between the AFM probe and the sample, and it is investigated based on finite element method (FEM) that the results of the test are affected by parameters.

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Rabe, U., S. Hirsekorn, M. Reinstädtler, T. Sulzbach, Ch Lehrer et W. Arnold. « Influence of the cantilever holder on the vibrations of AFM cantilevers ». Nanotechnology 18, n^o 4 (12 décembre 2006) : 044008. http://dx.doi.org/10.1088/0957-4484/18/4/044008.

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Liu, Shujie, Shuichi Nagasawa, Satoru Takahashi et Kiyoshi Takamasu. « Development of a Multi-Ball-Cantilever AFM for Measuring Resist Surface ». Journal of Robotics and Mechatronics 18, n^o 6 (20 décembre 2006) : 698–704. http://dx.doi.org/10.20965/jrm.2006.p0698.

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Semiconductor processing must be fast and highly accurate when measuring the surface profile of soft thin films such as photoresists. We propose doing so using a multi-ball-cantilever AFM, which covers a wide area at high speed. Each cantilever has a ball stylus with a diameter that does not plastically deform measured surfaces. We studied resist profiles and the influence of the AFM stylus on the resist surface. To verify our proposal’s feasibility, we simulated the relationship of the indenter shape, size, and load and resist surface deformation using the finite element method (FEM). We discuss the influence of the AFM stylus based on the force-displacement curve. Experiments using the multi-ball-cantilever AFM confirmed its feasibility for measuring surface profiles highly accurately.

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Dai, Gao Liang, F. Pohlenz, H. U. Danzebrink et L. Koenders. « Dimensional Measurements for Micro- and Nanotechnology ». Key Engineering Materials 381-382 (juin 2008) : 7–10. http://dx.doi.org/10.4028/www.scientific.net/kem.381-382.7.

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Metrology plays an important role in the development and commercialisation of micro and nanotechnology. For calibrating versatile micro- and nanoscale standards, a dimensional metrology instrument coupled with multi sensor heads including atomic force microscope (AFM), tactile stylus, laser focus sensor and assembled cantilever probes (ACPs) has been developed. Two kinds of ACPs are highlighted in the paper. One is fabricated by gluing a vertical AFM cantilever to a horizontal AFM cantilever using micro assembling techniques. It is applicable for direct and non-destructive measurements of sidewall surfaces. The other is an ACP ball probe designed for true 3D measurements of micro structures. It is realised by gluing a tungsten wire with a probing sphere ball, 40 ... 120 µm in diameter, to a horizontal AFM cantilever. The ACP ball probe has advantages such as small probing forces (<1µN) and high probing sensitivity. Some typical calibrations on micro and nano structures such as step height, grating and sphere calotte artefact are introduced.

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Dannberg, Oliver, Michael Kühnel et Thomas Fröhlich. « Entwicklung einer Cantileverkalibriereinrichtung ». tm - Technisches Messen 87, n^o 10 (25 octobre 2020) : 622–29. http://dx.doi.org/10.1515/teme-2020-0064.

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ZusammenfassungDas Messen kleiner Kräfte ist in vielen wissenschaftlichen Bereichen, wie beispielsweise der Physik oder Biologie, erforderlich. Bei Kräften im Bereich von Nanonewton werden typischerweise AFM-Cantilever als Kraftsensoren genutzt. Die Steifigkeit des Cantilevers muss bekannt sein um von der Durchbiegung auf die Kraft zu schließen. Aufgrund von Fertigungsabweichungen kommt es zu einer großen Streuung der Cantileversteifigkeit. Für eine präzise Kraftmessung muss daher jeder einzelne Cantilever kalibriert werden. Das derzeit genauste Kalibrierverfahren basiert darauf die Kraft-Weg-Kennlinie des Cantilevers statisch zu messen und ihren Anstieg zu bestimmen. In diesem Artikel wird ein neuartiger Prüfstand beschrieben welcher nach diesem Prinzip arbeitet. Ein Interferometer misst die Position und eine neuartige, eingelenkige Wägezelle die Kraft des Cantilevers. Die Wägezelle wurde in zwei unabhängigen Experimenten mit übereinstimmendem Ergebnis kalibriert. Abschließend werden die Messergebnisse einer Cantileverkalibrierung präsentiert.

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Lindsay, S. M. « Direct Magnetic Excitation of Cantilevers for Dynamic Force Microscocopy in Liquids ». Microscopy and Microanalysis 5, S2 (août 1999) : 1002–3. http://dx.doi.org/10.1017/s143192760001833x.

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The mechanical Q-factor of an AFM cantilever immersed in fluid is reduced to a small value (ca. 3) owing to viscous damping. Thus, a large driving force is needed to excite the cantilever into bending motion in fluid. There are two common methods for exciting cantilevers for dynamic force microscopy in fluids, illustrated in Figure 1. Fig. la illustrates acoustic excitation in which a piezoelectric transducer displaces the base of the cantilever, causing bending motion of the cantilever when the driving frequency is near to a bending resonance of the cantilever. Fig. lb shows magnetic excitation. In magnetic excitation, a magnetic field is used to cause bending of a magnetic cantilever either through magnetostriction or MXB forces.Acoustic excitation has the highest amplitude at mechanical resonances of the cantilever housing, with the result that the response is dominated by these sharp features,Fig. 2a. In contrast, the response to magnetic excitation is intrinsic to the cantilever, Fig. 2b. Thus, magnetic excitation permits the cantilever to be driven over a wide range of frequencies. This is important for calibration of the amplitude and for experiments involving time and concentration dependence in tip-sample interactions, e.g., anti-body recognition imaging.

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Stappers, Linda, et Jan Fransaer. « Colloidal Probe AFM Measurements of the Electrophoretic Force ». Key Engineering Materials 314 (juillet 2006) : 1–6. http://dx.doi.org/10.4028/www.scientific.net/kem.314.1.

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Colloidal probe atomic force microscopy is a very useful tool in the study of colloidal interactions. Although this technique has been applied to study interactions between a particle and a polarized electrode during electrodeposition, it has never been used to study interactions in high electric fields as encountered in electrophoretic deposition. In this work, a preliminary study was undertaken to verify whether colloidal probe AFM could be used to measure the electrophoretic force on a particle. It was found that the electrophoretic force could be detected by colloidal probe AFM under certain circumstances. In order to prevent that the contribution of the cantilever on the measurement of the electrophoretic force becomes large, the charge on the cantilever should be small compared to the charge of the particle, which is attached to the cantilever. Moreover, the area of cantilever surface which is oriented parallel to the electric field should be small to minimize the contribution of the cantilever.

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Gibson, Christopher T., Brandon L. Weeks, Chris Abell, Trevor Rayment et Sverre Myhra. « Calibration of AFM cantilever spring constants ». Ultramicroscopy 97, n^o 1-4 (octobre 2003) : 113–18. http://dx.doi.org/10.1016/s0304-3991(03)00035-4.

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Richter, C., P. Weinzierl, W. Engl, C. Penzkofer, B. Irmer et T. Sulzbach. « Cantilever probes for high speed AFM ». Microsystem Technologies 18, n^o 7-8 (29 février 2012) : 1119–26. http://dx.doi.org/10.1007/s00542-012-1454-8.

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Guerre, Roland, Ute Drechsler et Daniel Jubin et Michel Despont. « Low-cost AFM cantilever manufacturing technology ». Journal of Micromechanics and Microengineering 18, n^o 11 (26 septembre 2008) : 115013. http://dx.doi.org/10.1088/0960-1317/18/11/115013.

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Xie, H. Y. « Frequency shifts of cantilever in AFM ». Applied Surface Science 252, n^o 2 (octobre 2005) : 372–78. http://dx.doi.org/10.1016/j.apsusc.2005.01.014.

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Lübbe, Jannis, Matthias Temmen, Philipp Rahe, Angelika Kühnle et Michael Reichling. « Determining cantilever stiffness from thermal noise ». Beilstein Journal of Nanotechnology 4 (28 mars 2013) : 227–33. http://dx.doi.org/10.3762/bjnano.4.23.

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We critically discuss the extraction of intrinsic cantilever properties, namely eigenfrequency f n , quality factor Q n and specifically the stiffness k n of the nth cantilever oscillation mode from thermal noise by an analysis of the power spectral density of displacement fluctuations of the cantilever in contact with a thermal bath. The practical applicability of this approach is demonstrated for several cantilevers with eigenfrequencies ranging from 50 kHz to 2 MHz. As such an analysis requires a sophisticated spectral analysis, we introduce a new method to determine k n from a spectral analysis of the demodulated oscillation signal of the excited cantilever that can be performed in the frequency range of 10 Hz to 1 kHz regardless of the eigenfrequency of the cantilever. We demonstrate that the latter method is in particular useful for noncontact atomic force microscopy (NC-AFM) where the required simple instrumentation for spectral analysis is available in most experimental systems.

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Beltrán, F. J. Espinoza, J. Muñoz-Saldaña, D. Torres-Torres, R. Torres-Martínez et G. A. Schneider. « Atomic force microscopy cantilever simulation by finite element methods for quantitative atomic force acoustic microscopy measurements ». Journal of Materials Research 21, n^o 12 (décembre 2006) : 3072–79. http://dx.doi.org/10.1557/jmr.2006.0379.

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Measurements of vibrational spectra of atomic force microscopy (AFM) microprobes in contact with a sample allow a good correlation between resonance frequencies shifts and the effective elastic modulus of the tip-sample system. In this work we use finite element methods for modeling the AFM microprobe vibration considering actual features of the cantilever geometry. This allowed us to predict the behavior of the cantilevers in contact with any sample for a wide range of effective tip-sample stiffness. Experimental spectra for glass and chromium were well reproduced for the numerical model, and stiffness values were obtained. We present a method to correlate the experimental resonance spectrum to the effective stiffness using realistic geometry of the cantilever to numerically model the vibration of the cantilever in contact with a sample surface. Thus, supported in a reliable finite element method (FEM) model, atomic force acoustic microscopy can be a quantitative technique for elastic-modulus measurements. Considering the possibility of tip-apex wear during atomic force acoustic microscopy measurements, it is necessary to perform a calibration procedure to obtain the tip-sample contact areas before and after each measurement.

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Xie, Ping, Lei Zhang et Qing Ze Zou. « Resonance Suppression on Nanoscale Viscoelasticity Measurement ». Advanced Materials Research 528 (juin 2012) : 75–79. http://dx.doi.org/10.4028/www.scientific.net/amr.528.75.

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During the broadband viscoelasticity measurement process, when the frequency of the excitation force become high relative to the resonant frequency or the bandwidth of the instrument dynamics, the adverse instrument dynamics is motivated, which causes the cantilever resonance and generates large measurement errors in the measurement data. To solve this problem, an approach to suppress the cantilever resonance on the broadband viscoelasticity measurement is proposed. Firstly, Atomic force microscope (AFM) system dynamic is analyzed by using a dynamic signal analyzer (DSA) in the z-axis. And a notch filter is designed as a prefilter of the AFM system to filter the input drive voltage in order to offset the resonance peak in the AFM model. Secondly, an adaptive filter based on LMS is designed to further eliminate the residual cantilever resonance effects on the complex compliance of soft materials, referring to the Hertz contact model. Finally, the proposed approach is illustrated by implementing it to remove the cantilever resonance effects on the broadband viscoelasticity measurement of a polydimethylsiloxane (PDMS) sample using AFM.

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