New large-force piezoelectric motors and their applications in atomic resolution imaging under harsh conditions

It is difficult to obtain high quality atomic resolution images under harsh conditions when using current piezoelectric motors to build a scanning probe microscope. This article introduces several new types of compact piezoelectric motors with high output force that we developed recently, including GeckoDrive, PandaDrive, TunaDrive, SpiderDrive, and their variations,implemented using piezo plate stacks. Their structures, photographs, operation principles,and how they are adopted to build high quality scanning tunneling and magnetic force microscopes are presented. Of particular note are the high clarity, atomically resolved, scanning tunneling microscope (STM) images obtained without using any sound or vibration isolation, even in the extremely strong vibration environment inside a water-cooled magnet. Although these STM images were mainly taken using GeckoDrive, the TunaDrive can actually output bigger force, thus showing better promise in harsh condition applications. The SpiderDrive is a type of inertial piezoelectric motor, but it can output stronger force than traditional inertial motors so it also has good potential for imaging under harsh conditions.