Physics and Mathematics in atomic force microscope - Optimize feedback force interaction to achieve high resolution

This seminar is the first of the series: physics and mathematics of atomic force microscopy: choose the right parameter to optimize imaging resolution.

Atomic force microscope has numerous applications across many research fields. Compared to other microscopy technology, AFM is a versatile instrument that is also easy to maintain and require minimum sample preparation. However, many AFM users have this experience: when they use a familiar cantilever and parameter to study an unknown sample, they might encounter difficulties that cannot be easily solved by understanding the operational manual. This seminar we would analyze the most important parameters of atomic force microscope and discuss the physics and mathematical principles behind imaging optimization.

AFM uses the attractive and repulsive force between the cantilever tip and the sample to set the control feedback of the scanner. The force interaction between the tip and sample includes the short-range van de Waals attractive and repulsive force, long range electrical status force and magnetic force. Such force and their gradient distribution near the sample surface allows the instrument feedback system to maintain a constant distance between the tip and sample. By choosing different sets of parameters such as driving power, driving frequency and feedback setpoint, we could control and maintain the tip and sample at various attractive and repulsive force distance, therefore to control the imaging condition. Understanding such interaction would help us to optimize imaging parameters to achieve best resolution.

Song Xu, Ph.D., Sr. Application Scientist

Park Systems, Inc.

Dr. Song Xu is senior application scientist of Park Systems. He graduated from University of Science and Technology of China with BS degree, and later achieved a Ph.D. degree from Wayne State University in USA with specialty in atomic force microscope study of self -assembled monolayer. Dr. Xu has 18 year experience working with applications of atomic force microscope. Dr. Xu has 30 plus publications and two patents in the AFM field.