atomic force microscopeAtomic Force Microscope (AFM) is a high-resolution microscopy technique based on the interaction between probes and sample surfaces, which can measure the three-dimensional morphology and analyze various physical and chemical properties of samples at the nanoscale. Its core advantages lie in the absence of a vacuum environment, the ability to measure multiple materials (including insulators), and the ability to provide resolution far beyond optical microscopes (lateral resolution up to 0.1-0.2 nanometers, longitudinal resolution up to 0.01 nanometers). The following are the main measurement functions and application scenarios of AFM:

1. 3D Shape Reconstruction

Scan the sample surface with a probe, record the vertical displacement of the probe (Z-axis signal), and generate high-resolution 3D surface images.

Applications: Surface roughness analysis of nanomaterials, structural characterization of microelectronic devices, observation of surface morphology of biological samples such as cell membranes and DNA.

Case: Measurement of single atomic layer steps on graphene surface, with a height difference of only 0.34 nanometers.

2. Step height and contour analysis

Quantitatively measure vertical dimensions such as film thickness, nanowire diameter, and particle height.

Application: Quality assessment of semiconductor thin film growth, nanoparticle size statistics, coating uniformity testing.

1. Elastic modulus and hardness

Calculate the local Young's Modulus and hardness of the sample through Force Distance Curve analysis.

Application: Characterization of mechanical properties of polymer materials, study of hardness differences in biological tissues such as cartilage and tumor cells.

Case: Measuring the difference in elastic modulus between cancer cells and normal cells to assist in cancer diagnosis.

2. Adhesive and frictional forces

Measure the adhesion force (such as intermolecular forces) or lateral friction force between the probe and the sample surface.

Application: Performance evaluation of lubricating materials, research on the interaction between biomolecules (such as proteins and DNA) and substrates.

1. Conductive Atomic Force Microscopy (C-AFM)

Apply voltage to the probe, measure the surface current distribution of the sample, and generate a conductivity map.

Applications: Leakage analysis of semiconductor devices, uniformity testing of conductive polymer films, and evaluation of electrode contact quality in solar cells.

Case: Locate the micro areas with poor conductivity in solar cells and optimize the manufacturing process.

2. Electrostatic force microscope (EFM)

Measure the electrostatic force between the probe and the sample surface, reflecting the surface charge distribution or dielectric constant.

Application: Observation of ferroelectric material domain structure and analysis of surface charge traps on insulators.

1. Magnetic force microscope (MFM)

Using a magnetic coating probe to map the surface magnetic domain structure of the sample through magnetic interaction forces.

Applications: Development of hard disk magnetic heads, research on magnetic nanoparticle arrangement, characterization of spintronics devices.

Case: Observing the writing and reading process of nanoscale magnetic domains in magnetic storage media.

1. Scanning thermal microscope (SThM)

Heat the probe tip and measure the local thermal conductivity to generate a thermal distribution map.

Application: Thermal management optimization of microelectronic devices, analysis of thermal conductivity anisotropy of composite materials.

1. Chemical Force Microscopy (CFM)

Functionalization modification of probes (such as linking specific molecules) to recognize surface chemical composition through chemical bonding forces.

Applications: Single molecule detection, localization of active sites on catalyst surfaces, and specific recognition of biomolecules.

2. Dynamic observation of biological samples

Real time monitoring of cell movement, protein folding, or DNA hybridization processes in a liquid environment.

Case: Observing the dynamic distribution of receptors on the surface of living cell membranes and studying the mechanism of drug action.

1. Time resolved AFM

High speed scanning (millisecond level) captures surface morphology changes, such as phase transitions, crystal growth, or corrosion processes.

Application: Morphological evolution of battery electrode charging and discharging process, monitoring of early stages of metal corrosion.

1. AFM Raman combination

Combining AFM morphology with Raman spectroscopic chemical information to achieve synchronous analysis of morphology composition.

Application: Layer number and defect identification of two-dimensional materials (such as MoS ₂), and interface research of polymer composite materials.

2. AFM infrared combination

Realize nanoscale chemical imaging through needle tip enhanced infrared spectroscopy (TERS).

Application: Chemical composition analysis of biomolecule nanostructures, localization of active centers on catalyst surfaces.