Measuring intermolecular binding forces with the Atomic-Force Microscope: The magnetic jump method

1994 ◽  
Vol 52 ◽  
pp. 1054-1055
Author(s):  
J. H. Hoh ◽  
P. E. Hillner ◽  
P. K. Hansma
Keyword(s):  
Bond Strength ◽  
Atomic Force Microscope ◽  
Interaction Force ◽  
Intermolecular Forces ◽  
Atomic Force ◽  
Novel Approach ◽  
Binding Forces ◽  
Afm Cantilever ◽  
Paramagnetic Beads ◽  
Direct Readout

The atomic-force microscope (AFM) can measure forces between atoms and molecules with a sensitivity of <10−12 N. By coating the AFM tip with specific molecules the types of interactions that can be examined will be greatly extended. Recently tips with biotin attached have been used to probe surfaces coated with avidin or streptavidin, to measure the respective bond strength.We have developed a novel approach to measuring intermolecular forces with the AFM that employs paramagnetic beads coated with one of the molecules to be studied. Beads are incubated with a surface coated with the second molecule, and allowed to form a specific bond. A small magnet glued to an AFM cantilever is then advanced toward the bead until the bond with between the two molecules breaks and the bead “jumps” to the magnet. The deflection of the cantilever provides a direct readout of the interaction force at the “jump,” and thereby a measure of the bond strength.

A Fresh Insight Into the Microcantilever-Sample Interaction Problem in Non-Contact Atomic Force Microscopy

2004 ◽  
Vol 126 (2) ◽  
pp. 327-335 ◽  
Author(s):  
Nader Jalili ◽  
Mohsen Dadfarnia ◽  
Darren M. Dawson
Keyword(s):  
Imaging Techniques ◽  
Interaction Force ◽  
Intermolecular Forces ◽  
Scanning Tunneling ◽  
Atomic Interaction ◽  
Force Estimation ◽  
Contact Mode ◽  
Distributed Parameters ◽  
Atomic Force ◽  
Insight Into

The atomic force microscope (AFM) system has evolved into a useful tool for direct measurements of intermolecular forces with atomic-resolution characterization that can be employed in a broad spectrum of applications. The non-contact AFM offers unique advantages over other contemporary scanning probe techniques such as contact AFM and scanning tunneling microscopy, especially when utilized for reliable measurements of soft samples (e.g., biological species). Current AFM imaging techniques are often based on a lumped-parameters model and ordinary differential equation (ODE) representation of the micro-cantilevers coupled with an adhoc method for atomic interaction force estimation (especially in non-contact mode). Since the magnitude of the interaction force lies within the range of nano-Newtons to pica-Newtons, precise estimation of the atomic force is crucial for accurate topographical imaging. In contrast to the previously utilized lumped modeling methods, this paper aims at improving current AFM measurement technique through developing a general distributed-parameters base modeling approach that reveals greater insight into the fundamental characteristics of the microcantilever-sample interaction. For this, the governing equations of motion are derived in the global coordinates via the Hamilton’s Extended Principle. An interaction force identification scheme is then designed based on the original infinite dimensional distributed-parameters system which, in turn, reveals the unmeasurable distance between AFM tip and sample surface. Numerical simulations are provided to support these claims.

Adhesion and Friction Coupling in Atomic Force Microscope-Based Nanopushing

2012 ◽  
Vol 135 (1) ◽  
Author(s):  
Fakhreddine Landolsi ◽  
Fathi H. Ghorbel ◽  
James B. Dabney
Keyword(s):  
Numerical Simulations ◽  
Atomic Force Microscope ◽  
Contact Mechanics ◽  
Interaction Model ◽  
Research Interest ◽  
Visual Sensing ◽  
Atomic Force ◽  
Proposed Model ◽  
Theoretical Investigations ◽  
Afm Cantilever

The use of the atomic force microscope (AFM) as a tool to manipulate matter at the nanoscale has received a large amount of research interest in the last decade. Experimental and theoretical investigations have showed that the AFM cantilever can be used to push, cut, or pull nanosamples. However, AFM-based nanomanipulation suffers a lack of repeatability and controllability because of the complex mechanics in tip-sample interactions and the limitations in AFM visual sensing capabilities. In this paper, we will investigate the effects of the tip-sample interactions on nanopushing manipulation. We propose the use of an interaction model based on the Maugis–Dugdale contact mechanics. The efficacy of the proposed model to reproduce experimental observations is demonstrated via numerical simulations. In addition, the coupling between adhesion and friction at the nanoscale is analyzed.

Modeling the Thermomechanical Interaction Between an Atomic Force Microscope Cantilever and Laser Light

2012 ◽  
Author(s):  
Aarti Chigullapalli ◽  
Jason V. Clark
Keyword(s):  
Laser Beam ◽  
Resonance Frequency ◽  
Atomic Force Microscope ◽  
Laser Power ◽  
Laser Light ◽  
Laser Spot ◽  
Design Parameters ◽  
Atomic Force ◽  
Voltage Signal ◽  
Afm Cantilever

In this paper, we present the first computational model of the thermomechanical interaction between an atomic force microscope (AFM) cantilever and laser light. We validate simulation with experiment. Design parameters of our model include AFM laser power, laser spot position, and geometric and material properties of the cantilever. In the area of nanotechnology, the laser beam deflection method has been widely used in AFMs for detecting the cantilever’s deflection and resonance frequency. The laser deflection method consists of reflecting a laser beam off of an AFM cantilever onto a photo diode, which is converted to a voltage signal. Deflection of the cantilever results in a change in the laser reflection angle and a change in voltage signal. The mechanical properties of the cantilever affect the amount of deflection. Although much work has been done on increasing the sensitivity of the AFM, little work has been done on investigating the thermal effect of the laser-cantilever interaction. We observe that laser-induced thermal expansions in the AFM cantilever are measureable. Our simulated results suggest that both the laser power and spot positions significantly change the resonant response of the cantilevers. The resonance response is critical for the AFM tapping mode. In considering various laser powers, we observe that as we increase the power, the average temperature of the beam increases, which causes a decrease in resonance frequency. In considering various laser reflection spot positions, we find that as the laser spot moves away from the clamped end of the cantilever, the dissipation to the sample which is 6 m below the cantilever tip decreases, causing an increase in temperature but decrease in material softening. The results of our models are close to the experimental results with a relative error of 0.1%.

scholarly journals PROBING ATOMIC LEVEL INTERACTIONS IN NI NANORODS AND AFM CANTILEVER USING ATOMIC FORCE MICROSCOPY BASED F–D SPECTROSCOPY

2017 ◽  
Author(s):  
Sudipta Dutta ◽  
Mahesh Kumar Singh ◽  
M. S. Bobji
Keyword(s):  
Atomic Force Microscopy ◽  
Magnetic Interaction ◽  
Interaction Force ◽  
Small Scale ◽  
Magnetic Composite ◽  
Force Microscopy ◽  
Atomic Force ◽  
Lift Height ◽  
Afm Cantilever ◽  
Force Displacement

Atomic force microscopy based force-displacement spectroscopy is used to quantify magnetic interaction force between sample and magnetic cantilever. AFM based F–D spectroscopy is used widely to understand various surface-surface interaction at small scale. Here we have studied the interaction between a magnetic nanocomposite and AFM cantilevers. Two different AFM cantilever with same stiffness but with and without magnetic coating is used to obtain F–D spectra in AFM. The composite used has magnetic Ni nanophase distributed uniformly in an Alumina matrix. Retrace curves obtained using both the cantilevers on magnetic composite and sapphire substrate are compared. It is found for magnetic sample cantilever comes out of contact after traveling 100 nm distance from the actual point of contact. We have also used MFM imaging at various lift height and found that beyond 100nm lift height magnetic contrast is lost for our composite sample, which further confirms our F–D observation.

scholarly journals Оптимизация измерений вектора силы взаимодействия в атомно-силовой микроскопии

2021 ◽  
Vol 91 (6) ◽  
pp. 1043
Author(s):  
А.В. Анкудинов ◽  
А.М. Минарский
Keyword(s):  
Atomic Force Microscope ◽  
Satisfactory Agreement ◽  
Torsion Angle ◽  
Displacement Vector ◽  
Interaction Force ◽  
Optical Beam ◽  
Beam Deflection ◽  
Optimal Point ◽  
Atomic Force ◽  
The Ideal

The issue of optimization of measurements of three spatial components of the probe-sample interaction force and the corresponding displacement vector of the "ideal cantilever" is considered. To determine these components in an atomic force microscope with an optical beam deflection scheme, it is necessary to register the bending angles at least at two points on the rectangular cantilever and the torsion angle at any of them. It has been proven analytically that one optimal point is the intersection of the probe axis with the console plane. A method to calculate the position of another optimal point has been developed. An experiment was carried out to map the force and displacement vector, and satisfactory agreement with the theory was obtained.

Three-dimensional Nanorobotic Manipulations of Carbon Nanotubes

2002 ◽  
Vol 14 (3) ◽  
pp. 245-252 ◽  
Author(s):  
Lixin Dong ◽  
◽  
Fumihito Arai ◽  
Toshio Fukuda ◽  
◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Flexural Rigidity ◽  
Three Dimensional ◽  
Building Blocks ◽  
Intermolecular Forces ◽  
Multiwalled Carbon ◽  
Atomic Force ◽  
Manipulation System ◽  
Afm Cantilever ◽  
End Effectors

A nanorobotic manipulation system with 10 degreesof-freedom (DOFs) is presented and applied in 3-D manipulation of carbon nanotubes (CNTs) by controlling intermolecular forces. Manipulators are actuated with PicomotorsTM (New Focus Inc.) for coarse motions and PZTs for fine ones, and operated inside a scanning electronic microscope (SEM). Resolutions of manipulators are better than 30nm (linear) and 2mrad (rotary) for coarse motions, and within nanoorder for fine ones. Atomic force microscope (AFM) cantilevers are used as end-effectors, and van der Waals forces between them and objects are controlled by applying dielectrophoresis. Individual multiwalled carbon nanotubes (MWNTs) have been picked up on an AFM cantilever, placed between two cantilevers, and bent between a cantilever and sample substrate. As basic building blocks for more complex nanostructures and devices, CNT-junctions are constructed. A cross-junction was constructed with two MWNTs (∼ø40nm × 6μm and ∼ø50nm ö 7μm), and a T-junction was made of two MWNTs (∼ø40nm × 3μm and ∼ø50nm × 2μm). A kink junction is formed by bending an MWNT (∼ø40nm × 6μm) over its elastic limit for 20 times. Force measurements are performed and the flexural rigidity and Young's Modulus of an ∼ø30nm ∼7μm MWNT are estimated in situ to be 8.641 × 10-20Nm2 and 2.17TPa. Such manipulations are essential for both the property characterization of CNTs and the fabrication of functional nanosystems.

Virtual Manipulation of Multi-Wall Carbon Nanotubes with Atomic Force Microscope

2012 ◽  
Vol 263-266 ◽  
pp. 468-471
Author(s):  
Zhan Gao ◽  
Shu You Zhang ◽  
Jie Hua Wang
Keyword(s):  
Carbon Nanotubes ◽  
Atomic Force Microscope ◽  
Interaction Force ◽  
Multi Wall Carbon Nanotubes ◽  
Force Modeling ◽  
Atomic Force ◽  
Current State ◽  
Deformation Simulation ◽  
Set Up ◽  
Vr Simulator

This paper describes a virtual reality (VR) simulator for the manipulation of carbon multi-wall nanotubes with atomic force microscope (AFM). Major challenges in interfacing a human operator with tasks of manipulating nanotubes via a haptic VR interface are outlined. After a review of our previous efforts, we present the current state of our VR simulator for multi-wall nanotube manipulation. The collision detection, interaction force modeling, deformation simulation and haptic rendering of nanotubes are then discussed. Results of virtual manipulation of carbon nanotubes are presented within an immersive VR set-up.

DMCMN: Experimental/Analytical Evaluation of the Effect of Tip Mass on Atomic Force Microscope Cantilever Calibration

2009 ◽  
Vol 131 (6) ◽  
Author(s):  
Matthew S. Allen ◽  
Hartono Sumali ◽  
Peter C. Penegor
Keyword(s):  
Atomic Force Microscope ◽  
Fundamental Mode ◽  
Spring Constant ◽  
Mode Shapes ◽  
Contact Mode ◽  
Modified Method ◽  
Atomic Force ◽  
Afm Cantilever ◽  
Cantilever Probes ◽  
Tip Mass

Quantitative studies of material properties and interfaces using the atomic force microscope (AFM) have important applications in engineering, biotechnology, and chemistry. Contrary to what the name suggests, the AFM actually measures the displacement of a microscale probe, so one must determine the stiffness of the probe to find the force exerted on a sample. Numerous methods have been proposed for determining the spring constant of AFM cantilever probes, yet most neglect the mass of the probe tip. This work explores the effect of the tip mass on AFM calibration using the method of Sader (1995, “Method for the Calibration of Atomic Force Microscope Cantilevers,” Rev. Sci. Instrum., 66, pp. 3789) and extends that method to account for a massive, rigid tip. One can use this modified method to estimate the spring constant of a cantilever from the measured natural frequency and Q-factor for any mode of the probe. This may be helpful when the fundamental mode is difficult to measure or to check for inaccuracies in the calibration obtained with the fundamental mode. The error analysis presented here shows that if the tip is not considered, then the error in the static stiffness is roughly of the same order as the ratio of the tip’s mass to the cantilever beam’s. The area density of the AFM probe is also misestimated if the tip mass is not accounted for, although the trends are different. The model presented here can be used to identify the mass of a probe tip from measurements of the natural frequencies of the probe. These concepts are applied to six low spring-constant, contact-mode AFM cantilevers, and the results suggest that some of the probes are well modeled by an Euler–Bernoulli beam with a constant cross section and a rigid tip, while others are not. One probe is examined in detail, using scanning electron microscopy to quantify the size of the tip and the thickness uniformity of the probe, and laser Doppler vibrometry is used to measure the first four mode shapes. The results suggest that this probe’s thickness is significantly nonuniform, so the models upon which dynamic calibration is based may not be appropriate for this probe.

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