Contact mode imaging using AFM probes with exchangeable tips

This paper presents the design and evaluation of an Atomic Force Microscope (AFM) probe with exchangeable tips. It can be employed to replace tips worn out during imaging, or to exchange tips during multi-step nano-metrology and manipulation tasks. The probe employs a liquid meniscus-based micro-gripper at its end to enable exchange of tips. The design of the gripper and tip-supply station are discussed and the stiffness of the gripper is analyzed. Subsequently, the system is fabricated and evaluated by performing contact mode imaging of a calibration grating. The resulting topographical image is shown to be free of artifacts, thereby underscoring the fact that the micro-gripper can grip the AFM tip adequately well to resist the effect of lateral forces in contact mode AFM. It also shows that probes with exchangeable tips can be used in applications similar to that of a conventional AFM probe.