Atomic Force Microscopes are amazing instruments capable of extraordinary measurements. They are used routinely by scientists for research and development in the physical and life sciences, and are increasingly used by advanced technology companies for process development and control.
Despite their ability to exponentially advance various research applications, AFMs have an unfortunate reputation for being "finicky" and sometimes difficult to use.
Over the years many instrument companies have attempted to create easy-to-use AFMs that remedy the potential for AFM operator errors. Innovations within these AFMs can include their mechanical designs as well as automated software. There are pros and cons to these concepts:
Mechanics: Mechanical designers created pre-aligned light lever AFMs. While this means it's unnecessary for users to adjust the position of the laser and the photo detector, these AFMs often become misaligned and require costly factory re-alignment procedures.
Software: Programmers automated many of the steps involved in AFM operation, for example, tip approach and selection of frequency in vibrating mode. Unfortunately, automatic tip-approach software rarely compensates for the variations in surface contamination caused by ambient conditions.
Even when clever designs and automated software work to support easier instrument operation, several factors remain that must be addressed for optimal operation of any AFM. These are the very items that contribute to the "finicky" reputation of AFMs. They include:
External vibrations - In order to measure high-resolution images with a length scale of less than 1 nm, the AFM must be in a vibration-free environment, or housed within a vibration isolation system to filter out unwanted structural and acoustic vibrations that cause image interference.
Small delicate probes - All commercial AFMs use probes mounted on small Si substrates, these probes are inherently difficult to pick up and to place within the microscope.
Sample preparation - If a sample is not prepared correctly, it is impossible to acquire a quality image.
Ambient Conditions - Humidity and other conditions can have a dramatic impact on the performance of an AFM. AFMs operated in a very humid environment behave much differently than AFMs operated in dry environments because of the environmental impacts on the tip-sample interaction.
Despite these challenges, many AFMs are in use around the world and provide amazing results. The secret to success lies in the AFM user receiving proper training on the use of the AFM. Unfortunately, it's often the case that the knowledge necessary for AFM operation is passed on from one student or researcher to another as "tribal knowledge". But the skill sets required to successfully operate an AFM need a much more rigorous approach. Proper training on all aspects of AFM operation is necessary.