The Atomic Force Microscope (AFM): An Absolute Powerhouse

The atomic force microscope is a force to be reckoned with in the scientific world. This scientific instrument has come a long way in terms of its total number of applications and overall practicality.

Atomic force microscopes are a highly desirable technology because they provide high resolution images of the smallest objects and particles. They are almost exclusively used on a nanoparticle scale to measure the tiniest objects. Think of minuscule cell walls and subatomic particles or various protein molecules that need to be studied by researchers in the pharmaceutical industry.

There are many applications and uses for atomic force microscopes, but they are usually only used in highly specialized practices because they are incredibly expensive to build and maintain. Scientists and researchers in niche industries and fields primarily use atomic force microscopes.

In this article, we aim to break down what makes these microscopes so special, how they work on a basic level, and talk about why they’re so lauded in certain scientific circles.

What Is an Atomic Force Microscope?

View of nanoparticles under atomic force microscope

Despite its imposing name, an atomic force microscope isn’t a particularly violent kind of microscopy. If anything, it’s a nuanced approach to analyzing physical surfaces using a physical tip.

While electron microscopy uses electron beams to form an image using photons, atomic force microscopes function a little differently. They use an AFM probe to conduct a raster scan of any particular sample surface. What is a raster scan, you may ask?

We’ll get into that a bit, but what’s important to know now is that atomic force microscopes are aptly named – they delve into the depths of what makes an object what it is at the most basic level. This probe microscope helps showcase particles and objects on a subatomic scale.

What Is a Raster Scan?

Raster scans are essential to the atomic force microscope utilization process. But what exactly is raster scanning? It’s the process of scanning an image in horizontal lines, from left to right and top to bottom, to create an identical rendering of that image. Imagine how an old-school printer prints out a document line by line.

While this is a process that is popular in television because of the way that it is easily able to image things, raster scanning in microscopy is very different. Atomic force microscopy uses raster scanning to form a feedback loop, which in turn changes the ramifications to form an AFM image.

Raster scanning is an intricate process that takes a lot of time to explain, but atomic force microscopes use the process to give a detailed view of very, very small nanoparticles.

Modes of Operation for an Atomic Force Microscope

There are three basic modes of operation for an atomic force microscope. They are contact mode, non-contact mode, and tapping mode. But what exactly do these different modes mean, and what do they signify, really? Well, let’s dive into this realm.

Contact mode generally refers to when the sharp tip characteristic of atomic force microscopes comes in direct contact or directly touches the surface of whatever is being analyzed.

Non-contact mode is also a self-explanatory mode of an atomic force microscope, but raster scanning is the primary method to display an accurate surface image. In this case, the cantilever tip of the microscope is drawn close but doesn’t come in actual contact with the surface being analyzed.

Finally, there’s the tapping mode of the atomic force microscope, which scans any given surface with an oscillating cantilever. This cantilever, or sharp tip, is used in the other imaging types we’ve mentioned.

However, the difference in the tapping mode is that it is utilized when topography is something to be considered when imaging a surface. The tapping mode is particularly useful if an object or area is rough or expansive.

Applications of Atomic Force Microscopes

Atomic force microscopes have all sorts of practical uses. These AFM imaging devices are beneficial for viewing subatomic particles or anything measured on a scale of nanometers. While this type of measurement could quantify many particles or pieces of single-celled life, it helps to remember that atomic force microscopes have quite a wide range of usability. They have been utilized in all sorts of industries to serve a variety of purposes.

One such purpose of atomic force microscopes is in the pharmaceutical industry. Atomic force microscopes can visualize and develop high-resolution images of specific proteins, amoebas, pathogens, viruses, bacteria, and more. This kind of imaging device is highly useful when accurately drawing up imagery to analyze for developing new drugs or anything of that matter.

Another use of atomic force microscopy can be seen in biology. Because atomic force microscopes can bring up high-quality images of all sorts of tiny particles, scientists can rely on them to show accurate images of single-celled organisms and other biological samples.

These include different strains of bacteria, tardigrades, and much more. Creating comprehensive images of such tiny elements can be a boon to just about anyone in any industry.

Atomic force microscope in lab

Using an Atomic Force Microscope

Atomic force microscopes are a type of probe microscope with a highly specialized use. Atomic force microscopy can detect the barest changes between subatomic surfaces, making them instrumental when engaging with the tiniest material.

However, most general members of the population will never need this level of nanotechnology. We hope that this guide provided by us at Optical Mechanics proved helpful in learning more about the AFM technique.