Design and Control of a Dual-Probe Atomic Force Microscope

Abstract

Current atomic force microscopes (AFMs) support single-probe operation, in which one nanosized tip enables versatile operations such as surface imaging, nanomanipulation, and nanomanufacturing to be performed, although one at a time. Some AFM operations involve switching between imaging and the operational mode, which is cumbersome, challenging, and limiting, particularly when different probe geometries are preferred for each mode. This paper presents a new dual-probe atomic force microscope (DP-AFM) that has two independent probes operating in a common workspace. Such a setup enables two AFM operations to be carried out simultaneously. For instance, one probe can be used to image, while the other probe performs one of the many tip-based processes. The hardware and software design involved in developing the DP-AFM is discussed in detail. Furthermore, to demonstrate the capability of dual-probe arrangement, a controller is developed for real-time plowing depth control, where one probe is used to plow the surface, while the other is used to image the plow profile, thus enabling real-time feedback control of the AFM plow process. Experimental results show that the plow depth can be regulated with nanometer-level accuracy.