An STM for biological applications: Bioscope

Abstract

We present an STM with an improved coarse positioning system and a large scan area which is especially suitable for biological applications. Three stepper motors are used to move an X‐Y‐Z table. Movements of motor axes are geared down to drive micrometer spindles so that steps of 250 nm can be performed. The stepper motors can be uncoupled from the STM for scanning operation. A piezo tube is used to scan areas of up to 10times10μm with low voltage operation. Probes can be scanned in air or in electrochemical cells. High stability against thermal drift and vibrations is achieved by a rigid and symmetrical design. 1988 Blackwell Science Ltd