Mechanically Stable Tuning Fork Sensor With High Quality Factor for the Atomic Force Microscope

摘要

A quartz tuning fork was used instead of cantilever as a force sensor for the atomic force microscope. A tungsten tip was made by electrochemical etching from a wire of 50 mu m diameter. In order to have mechanical stability of the tuning fork, it was attached on an alumina plate. The tungsten tip was attached on the inside end of a prong of a tuning fork. The phase shift was used as a feedback signal to control the distance between the tip and sample, and the amplitude was kept constant using a lock-in amplifier and a homemade automatic gain controller. Due to the mechanical stability, the sensor shows a high quality factor (approximate to 10(3)), and the image quality obtained with this sensor was equivalent to that of the cantilever-based AFM. SCANNING 36:632-639, 2014. (c) 2014 Wiley Periodicals, Inc.