Low-temperature atomic force microscope using piezoresistive cantilevers

This article describes the design of an easy-to-operate low-temperature atomic force microscope (AFM) that incorporates piezoresistive cantilevers. The instrument is easier to build and to operate at cryogenic temperatures than AFMs based on laser deflection schemes or interferometers because no mechanical adjustments of the instrument are necessary after a change of temperature. The effects of thermal expansion on the AFM’s tip-to-sample distance are minimized by the use of a double tube scanner assembly. The design includes a simple mechanism that locks the sample holder in place as the temperature is lowered. This AFM is compact and rigid, enabling it to be used in a conventional cryogenic liquid-storage Dewar. All of the materials used in the construction of the AFM are ultra-high-vacuum compatible.