Force-feedback joystick as a low-cost haptic interface for an atomic-force-microscopy nanomanipulator

In order to manipulate materials at the nanometer scale, new methods and devices have to be developed. A nanomanipulator interface was designed and implemented in a commercial atomic-force-microscope (AFM) system. With the aid of a positioning joystick, direct positioning of the AFM probe with nanometer precision was possible. A commercial force-feedback joystick served as a haptic interface and provided the user with real-time feeling of the tip-sample interactions. Due to the open design, the manipulator interface could be used with other microscopes of the SPM family. In addition, the nanomanipulator and an UV-laser microbeam for photoablation were combined on an inverted optical microscope. To test the nanomanipulator, human metaphase chromosomes were dissected using both photoablation and mechanical AFM manipulation. The experimental results show that by combining both methods, biological material can be manipulated on different size scales in one integrated instrument. The effects of manipulation on the chromosome were studied in detail by AFM. Sub-400 nm cuts were achieved by photonic ablation. Chromosomal fragments of a size less than of 500 nm could be isolated. By means of mechanical microdissection, different cut sizes ranging from 80 um to 500 nm could be easily obtained by applying different load forces.