A MICROCONTROLLER-BASED SYSTEM FOR PIEZOSCANNER NONLINEARITY CORRECTION - ATOMIC-FORCE MICROSCOPE

Scanning probe microscopes use piezoelectric actuators (piezoscanners) as extremely sensitive and exact positioners for small scaled sample scannings. They are capable of making fine movements along the X, Y, a nd Z axes, with displacements that can vary from several hundreds of a ngstroms to some micrometers. For high amplitude sweeps, the displacem ent response results in visible distortions due to the intrinsic nonli nearity effects of the piezoelectric tube. This work proposes the nonl inearity correction by means of a microcontroller-based system which p roduces (in real time) the correction values using the piezoscanner qu adratic transfer function, adapted to an atomic force microscope (AFM) of its own construction. The AFM is intended to be used with biologic al samples. Other correction methods are described. (C) 1998 American Institute of Physics. [S0034-6748(98)03410-8].