DESIGN OF A SCANNING PROBE MICROSCOPE

A compact scanning probe microscope for operation in air and liquid is described. The probe techniques implemented are scanning tunnelling m icroscopy and scanning ion conductance microscopy. The software, elect ronics, mechanical construction and some representative measurements w ill be presented here. The compact and concentric microscope head is b uilt around a commercial piezoelectric inchworm motor. The scanner is a standard piezo tube. An analogue feedback system is used for taking images, while digital control of the probe-sample distance is used for other experiments, such as measurements of current-voltage characteri stics. A Macintosh personal computer is used for control and presentat ion of data. A simple method to make scanning tunnelling microscope ti ps suitable for electrochemical use is described. The microscope has a high resonance frequency (9.6 kHz), low noise (0.01 nm Hz-1/2 at 10 H z), low thermal drift (less than 0.1 nm min-1), and high acoustical no ise suppression. The current-distance-dependency of the scanning ion c onductance microscope was found to be linear.