Micromachined sample stages to reduce thermal drift in atomic force microscopy

Abstract

Thermal drift in AFM is a significant bottleneck for stability and accuracy of measurements especially for single-molecule mechanics measurements. The authors present design, fabrication and experimental characterization of micromachined sample stages to reduce thermal drift in atomic force microscopy (AFM). The devices are made of titanium and aluminum fabricated on a silicon wafer. The devices thermo-mechanically match commonly used commercially available AFM cantilevers and reduce thermally induced deflection of cantilevers when used as sample stages. An experimental setup is described to characterize steady state and dynamics of the fabricated devices. The experimental data indicates a reduction of 54 % in thermally induced deflection using microstages for a specific cantilever type for force spectroscopy experiments. The results of biomolecular force spectroscopy experiments are presented for biotin/streptavidin molecular pairs. The experiments indicate that the surface of microstages can be functionalized successfully for biomolecular experiments.