Atomic force microscope (AFM), the key tool for surface analysis

Analyzing materials exhaustively to discover the appearance of defects and their possible solutions is on the rise today, therefore, we present an analysis technique, used by our forensic engineering team, which will allow us to know the surface with great precision. of materials: atomic force microscopy or AFM.
Find out what it is about in this post!

History of atomic force microscopy, the origin of AFM

Interest in the topography of materials has always been present in many branches of science, since the surface properties of a material directly influence its applicability.
First, the AFM technique was presented as a versatile tool, capable of working effectively in materials science, from a chemical, physical or biological point of view. In addition, its importance was increased by allowing the quantitative study of the three-dimensional structure of the surface and its properties such as mechanical, electronic, magnetic and chemical. Likewise, he highlighted its use in vacuum or liquid environments, allowing even to evaluate the changes in the surface properties of a material when a chemical reaction is taking place on its surface.

Theoretical operation of the AFM

Unlike other analysis techniques such as SEM or TEM that obtain the signal through optical lenses that interact with electrons, it uses a scanning probe, that is, it actually analyzes the surface of the sample point by point with a fine tube, creating finally an image of all the measured points.
This measurement probe allows to analyze the surface properties of the sample with a high lateral and vertical resolution. In conclusion, it has been shown that AFM can achieve a vertical subnanometric resolution and a lateral resolution of a few nanometers, being able to create an image with a length of the order of 0.1 mm at less than 1 nm.

AFM Applications

With an AFM, the topography, and also the profiles of almost any surface, can be measured with nanometric resolution. The instrument is based on its mechanical detection of the surface with a very fine tip and is used for imaging and spectroscopic analysis of a variety of surface and material properties with nanometric resolution.
Also, it acts as the support for the development of nanometric scale materials, allowing their characterization and understanding. Therefore, the AFM has numerous applications in different branches of science:

Chemistry

It stands out for its use in the analysis of the properties of an electrochemical cell where a chemical reaction is taking place.

Materials science

It is worth highlighting its use in the detection of defects in paintings.

Biophysics

The study of cell mechanics can be carried out using AFM.

Microelectronics

Using the AFM allows to characterize semiconductors

Biology

One of the main uses is in the analysis of living cell environments

Use of AFM to determine electrochemical cell properties

Cell mechanical study through AFM

Analysis of living cell environments with the AFM technique

Advantages and disadvantages of AFM

Atomic force microscopy was a breakthrough in surface analysis, allowing investigation of the nanometric world. However, its use is very specific and has some limitations. Next, we will see the advantages and disadvantages offered by this analysis technique:

Main advantages of atomic force microscopy

• It was able to analyze materials of any nature, regardless of their electrical conductivity
• Measurements are possible in any environment, environment, vacuum or liquid
• It obtains measurements with a vertical subnanometric resolution and a lateral resolution of a few nanometers;
• Mapping and roughness profiles in three dimensions
• It allows the study of surface properties such as adhesion, hardness, conductivity, electrical, magnetic or chemical composition

Disadvantages of atomic force microscopy

• The time required to measure large surfaces is very high since the scanned area does not normally exceed 150×150 mm, and the maximum height is of the order of microns
• Image quality is highly dependent on probe geometry
• The scanning speed is usually slow compared to other types of microscopy such as scanning electron microscopy.

Success story using the AFM technique

Using the AFM technique, it is possible to determine information on the topography of a surface by obtaining images and profiles of the surface roughness.
First, pores, depending on their size, can be detected using this technique. Second, surface defects can be observed and their profile traced. A clear example is, to know if the use of a coating or coating modifies the roughness of a material and can subsequently affect its adhesion or aesthetic appearance.In summary, the analysis of the surface of materials as a tool for product improvement is fashionable, and atomic force microscopy can be the means to study and solve defects that appear on the surface of any material.
Do you need to know the topography of your sample with great precision? Would you like to analyze the changes that the properties of the surface of your sample experience when a chemical reaction takes place? Do you want to apply atomic force microscopy in any of your Projects? Contact us!