How AFM works

Introduction

What is atomic force microscopy (AFM)?
How does an AFM work?
What AFM modes do I really need?
How do I get started with AFM?

These are all legitimate questions that quickly come to mind when first buying or starting with AFM.

With this, we hope to set you on the right track with some general information on atomic force microscopy and atomic force microscopes. You may also find the microscope simulation mode and operating instructions included with our control software helfpful. It's free to install and try.

If you need more detailed or specific information, just contact us for further assistance.

History and Background of Atomic Force Microscopy

The field of scanning probe microscopy (SPM) began in the early 1980s with the invention of the scanning tunneling microscope (STM) by Gerd Binnig and Heinrich Rohrer, awarded with the Nobel Prize in Physics in 1986. In the same year, a major breakthrough was made with the invention of the atomic force microscope (AFM) by Gerd Binning, Calvin Quate and Christoph Gerber, which continues to revolutionize nanoscale characterization and measurements ever since. Today AFM is the most popular type of SPM, causing the terminology of AFM and SPM to be often used synonymously. In case of AFM, the probe is a cantilever, generally having a tip at its free end. The superfamily of SPM probes can also include simple metal wires (as used in STM) or glass fibers (as used for scanning nearfield optical microscopy/SNOM/NSOM).

Nowadays AFM includes a wide variety of methods in which the probe interacts with the sample in different ways in order to characterize various material properties. AFM can characterize a wide array of mechanical properties (e.g. adhesion, stiffness, friction, dissipation), electrical properties (e.g. capacitance, electrostatic forces, work function, electrical current), magnetic properties, and optical spectroscopic properties. In addition to imaging, the AFM probe can be used to manipulate, write, or even pull on substrates in lithography and molecular pulling experiments.

Due to its flexibility, the atomic force microscope has become a common tool for material characterization alongside optical and electron microscopy, achieving resolutions down to the nanometer scale and beyond. The AFM can operate in environments from ultra-high vacuum to fluids, and therefore cuts across all disciplines from physics and chemistry to biology and materials science.

This article describes the operating principle and most common measurement modes of atomic force microscopy, and some of the many properties that can be measured with AFM on the nanoscale.