Related Experiment Video
Updated: Jan 30, 2026
06:45
Force Spectroscopy of Single Protein Molecules Using an Atomic Force Microscope
Published on: February 28, 2019
9.4K
The qPlus sensor, a powerful core for the atomic force microscope
1Institute of Experimental and Applied Physics, University of Regensburg, Universitätsstrasse 31, D-93040 Regensburg, Germany.
The Review of Scientific Instruments
|February 3, 2019
Summary
Atomic force microscopy (AFM) advancements, particularly with the qPlus sensor and frequency modulation AFM (FM-AFM), enable subatomic resolution imaging and force spectroscopy. These techniques offer unprecedented detail in surface science and nanoscience applications.
Area of Science:
- Surface science
- Nanoscience
- Materials science
- Chemistry
- Biology
Background:
- Atomic force microscopy (AFM), developed in 1986, is a versatile tool for imaging and manipulation across various scientific disciplines.
- AFM evolved from scanning tunneling microscopy (STM), replacing the STM tip with a force sensor to measure chemical forces.
- Significant instrumentation progress has been made in AFM, focusing on force sensors, tips, and detection mechanisms.
Purpose of the Study:
- To highlight advancements in AFM force sensors, specifically the qPlus sensor and its self-sensing capabilities.
- To discuss the principles and advantages of Frequency Modulation Atomic Force Microscopy (FM-AFM) for high-resolution imaging and force spectroscopy.
- To explore the applications and limiting factors of these advanced AFM techniques.
Main Methods:
- Utilizing qPlus sensors, which leverage the piezoelectricity of quartz for self-sensing, enabling parallel STM and AFM measurements.
- Employing Frequency Modulation Atomic Force Microscopy (FM-AFM) to detect force gradients by measuring changes in cantilever oscillation frequency.
- Implementing noncontact AFM operation to separate conservative and dissipative forces and achieve high signal-to-noise ratios.
Main Results:
- The qPlus sensor achieves subatomic spatial resolution in AFM, surpassing STM capabilities.
- FM-AFM provides atomic and subatomic resolution, along with force spectroscopy at sub-piconewton sensitivity.
- Simultaneous AFM and STM measurements are feasible with FM-AFM due to its noncontact operation.
Conclusions:
- Advanced AFM techniques, particularly those using qPlus sensors and FM-AFM, offer unprecedented resolution and sensitivity.
- These methods are crucial for detailed studies of atomic interactions, spin-dependent forces, and molecular structures.
- Continued development in AFM instrumentation promises further breakthroughs in nanoscience and surface characterization.
More Related Videos
09:27Automation of Bio-Atomic Force Microscope Measurements on Hundreds of C. albicans Cells
Published on: April 2, 2021
4.4K
08:31Probing Surface Electrochemical Activity of Nanomaterials using a Hybrid Atomic Force Microscope-Scanning Electrochemical Microscope AFM-SECM
Published on: February 10, 2021
7.5K
Related Concept Videos
01:08Atomic Force Microscopy
4.5K
Atomic force microscopy (AFM) is a type of scanning probe microscopy that can analyze topographic details of various specimens like ceramics, glass, polymers, and biological samples. AFM offers over 1000 times more resolution than the optical imaging system. Images generated from AFM are three-dimensional surface profiles, offering an advantage over the flat, two-dimensional images from other imaging techniques.
The AFM Probe
The probe is regarded as the heart of any AFM setup and comprises the...
The AFM Probe
The probe is regarded as the heart of any AFM setup and comprises the...
4.5K
00:57Power Expended by a Constant Force
9.2K
The relationship between work done and the time taken to do it can be explained using the concept of power. For example, several sprinters in a race may have the same velocity when they reach the finish line, therefore doing the same amount of work, but the winner does it in the least amount of time. Thus, power is defined as the rate of doing work. Since work can vary as a function of time, the average power is defined as the work done during a time interval, divided by the time interval.
9.2K
02:44Atomic Orbitals
43.8K
An atomic orbital represents the three-dimensional regions in an atom where an electron has the highest probability to reside. The radial distribution function indicates the total probability of finding an electron within the thin shell at a distance r from the nucleus. The atomic orbitals have distinct shapes which are determined by l, the angular momentum quantum number. The orbitals are often drawn with a boundary surface, enclosing densest regions of the cloud.
43.8K
02:10The Nucleosome Core Particle
14.4K
Nucleosomes are the DNA-histone complex, where the DNA strand is wound around the histone core. The histone core is an octamer containing two copies of H2A, H2B, H3, and H4 histone proteins.
The paradox
Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their main responsibility is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. While on the other hand, they must allow polymerase enzymes to access DNA...
The paradox
Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their main responsibility is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. While on the other hand, they must allow polymerase enzymes to access DNA...
14.4K
03:13Intermolecular Forces
70.8K
Atoms and molecules interact through bonds (or forces): intramolecular and intermolecular. The forces are electrostatic as they arise from interactions (attractive or repulsive) between charged species (permanent, partial, or temporary charges) and exist with varying strengths between ions, polar, nonpolar, and neutral molecules. The different types of intermolecular forces are ion–dipole, dipole–dipole, hydrogen bonds, and dispersion; among these, dipole–dipole, hydrogen...
70.8K
03:21The Energies of Atomic Orbitals
30.1K
In an atom, the negatively charged electrons are attracted to the positively charged nucleus. In a multielectron atom, electron-electron repulsions are also observed. The attractive and repulsive forces are dependent on the distance between the particles, as well as the sign and magnitude of the charges on the individual particles. When the charges on the particles are opposite, they attract each other. If both particles have the same charge, they repel each other.
30.1K