Quality factor enhancement of an Atomic Force Microscope micro-cantilever using piezoelectric shunt control

The quality (Q) factor of the Atomic Force Microscope (AFM) micro-cantilever influences both the maximum scan speed and image quality when operating in tapping mode. Increasing the Q factor of the micro-cantilever results in an increase in force sensitivity and a reduction in tapping force. Active piezoelectric shunt control uses an active electrical impedance to modify the mechanical dynamics of the cantilever. An increase in the effective Q factor of a piezoelectric AFM micro-cantilever by over 25 times has been demonstrated using this technique.

I. INTRODUCTION

The Atomic Force Microscope (AFM) [1] utilizes the attractive and repulsive forces between a sample surface and a sharp tip, located on the underside of a micro-cantilever, to obtain 3D images of the surface with sub-nanometer resolution. The AFM is used to investigate the surface topography of a wide range of samples in air and liquid [2], [3] with far greater resolution than traditional optical microscopes.