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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, and Z axes, with displacements that can vary from several hundreds of angstroms to some micrometers. For high amplitude sweeps, the displacement response results in visible distortions due to the intrinsic nonlinearity effects of the piezoelectric tube. This work proposes the nonlinearity correction by means of a microcontroller-based system which produces (in real time) the correction values using the piezoscanner quadratic transfer function, adapted to an atomic force microscope (AFM) of its own construction. The AFM is intended to be used with biological samples. Other correction methods are described.

We have investigated the aggregation into micelles of nonionic amphiphiles in water through Monte Carlo simulations of a very simple model system. Amphiphiles and water are modeled, respectively, as three‐site and one‐site molecules on a square lattice. The model presents characteristic properties of experimental micellization, namely, monomer vs amphiphile concentration with a plateau above a ‘‘critical’’ concentration (cmc) and a distribution of micelle sizes (polydispersity). Results of the numerical experiment were compared with predictions from statistical thermodynamic theory. Sample size and relaxation properties of the simulation have also been analyzed.