We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

What is an Atomic Force Microscope (AFM)?

Michael Anissimov
Updated May 21, 2024
Our promise to you
All The Science is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At All The Science, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject-matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

An atomic force microscope (AFM) is an extremely precise microscope that images a sample by rapidly moving a probe with a nanometer-sized tip across its surface. This is quite different than an optical microscope which uses reflected light to image a sample. An AFM probe offers a much higher degree of resolution than an optical microscope because the size of the probe is much smaller than the finest wavelength of visible light. In an ultra-high vacuum, an atomic force microscope can image individual atoms. Its extremely high resolution capabilities have made the AFM popular with researchers working in the field of nanotechnology.

Unlike the scanning tunneling microscope (STM), which images a surface indirectly via measuring the degree of quantum tunneling between the probe and sample, in an atomic force microscope the probe either makes direct contact with the surface or measures incipient chemical bonding between probe and sample.

The AFM uses a microscale cantilever with a probe tip whose size is measured in nanometers. An AFM operates in one of two modes: contact (static) mode and dynamic (oscillating) mode. In static mode, the probe is kept still, while in dynamic mode it oscillates. When the AFM is brought close to or contacts the surface, the cantilever deflects. Usually, on top of the cantilever is a mirror which reflects a laser. The laser reflects onto a photodiode, which precisely measures its deflection. When the oscillation or position of the AFM tip changes, it is registered in the photodiode and an image is built up. Sometimes more exotic alternatives are used, such as optical interferometry, capacitive sensing or piezoresistive (electromechanical) probe tips.

Under an atomic force microscope, individual atoms look like fuzzy blobs in a matrix. To provide this degree of resolution requires an ultra-high vacuum environment and a very stiff cantilever, which prevents it from sticking to the surface at close range. The downside of a stiff cantilever is that is requires more precise sensors to measure the degree of deflection.

Scanning tunneling microscopes, another popular class of high-precision microscopes, usually have better resolution than AFMs, but an advantage of AFMs is that they can be used in a liquid or gas ambient environment whereas an STM must operate in high vacuum. This allows for the imaging of wet samples, especially biological tissue. When used in ultra-high vacuum and with a stiff cantilever, an atomic force microscope has similar resolution to an STM.

All The Science is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Michael Anissimov
By Michael Anissimov
Michael Anissimov is a dedicated All The Science contributor and brings his expertise in paleontology, physics, biology, astronomy, chemistry, and futurism to his articles. An avid blogger, Michael is deeply passionate about stem cell research, regenerative medicine, and life extension therapies. His professional experience includes work with the Methuselah Foundation, Singularity Institute for Artificial Intelligence, and Lifeboat Foundation, further showcasing his commitment to scientific advancement.
Discussion Comments
By David09 — On Dec 23, 2011

@miriam98 - With this degree of resolution imagine what you could discover if you sampled biological tissue.

Perhaps you could penetrate cells themselves to see how they function, or identify the operative genes in a cancer tumor to figure out how it works. I am a great believer in nanotechnology and AFM imaging is a great application of that technology in my opinion.

By miriam98 — On Dec 22, 2011

@Mammmood - That’s an interesting question. Since the probe is thinner than visible light it would be difficult to see. The cantilever however is, I think, an extension from some machine that is visible.

I think that the machines are used to direct the microscope to the particle that they want analyzed. What I find fascinating is that they can actually view atoms with these things!

Up until now I thought that only electron microscopes could view atomic particles. Perhaps nanotechnology and the AFM microscope will open up new insights into the subatomic world.

By Mammmood — On Dec 21, 2011

An AFM microscope that small would be nearly invisible wouldn’t it? If you’re touching the tip of an atom or a nanoparticle, then I would assume that the tip would have to be just as small.

I can’t imagine a tip that is thinner than a wave of light. I think that were it not for the deflected laser onto the photodiode it would be nearly impossible to see the microscope or what it’s doing.

That’s my guess anyway. I don’t know much about nanotechnology.

Michael Anissimov
Michael Anissimov
Michael Anissimov is a dedicated All The Science contributor and brings his expertise in paleontology, physics, biology...
Learn more
All The Science, in your inbox

Our latest articles, guides, and more, delivered daily.

All The Science, in your inbox

Our latest articles, guides, and more, delivered daily.