Control system for an AFM based nanomanipulation station

Abstract

The atomic force microscope (AFM) has proven to be a valuable instrument for the characterization and manipulation of biological objects. When using the AFM as a nanomanipulation tool, two principal problems arise. First, when manipulating with the AFM, the manipulation process has to be performed in a blind way. This can partially be solved by using virtual imaging and force feedback techniques. A second, more challenging problem is caused by tip contamination and the selection of the AFM tip. If the same probe is used for manipulation and imaging, tip contamination can result in decreased image quality. Furthermore, requirements on both tip shape and material may vary for manipulation and imaging. Addressing both problems, an automated microrobot station is proposed, utilizing nanomanipulation robots equipped with self-sensing AFM tips (piezoresistive cantilevers) working in cooperation with a conventional AFM. The system will not only benefit from a decoupling of imaging and manipulation, it will also allow simultaneous measurements (electrical, mechanical and thermal conduction) in different points of the sample. Due to spatial uncertainties arising from thermal drift, hysteresis and creep afflicted actuators, the development of a control system for the cooperation of microrobot and AFM is challenging. Current research efforts towards a nanohandling robot station combining both an AFM cantilever equipped microrobot and an AFM are presented.