Serial-Kinematic Hybrid Electromagnetic-Piezoelectric AFM Scanner for High-Throughput Raster Scanning

High-throughput raster scanning enables high-rate atomic force microscopy (AFM) imaging in a large area. This article proposes a novel serial-kinematic tri-axial AFM scanner to meet the different stroke and bandwidth requirements of each axis in AFM raster scanning. By means of hybrid actuation, this scanner combines the high-force-density and long-range merits of the normal-stressed electromagnetic actuator (NSEA) and the high-resonant-frequency advantage of the piezoelectric actuator (PEA). The X - and Y -stages are actuated by the self-developed NSEAs. Specifically, the X -axial moving mass is minimized by elaborately designing the serial kinematics and the flexure-internal structure. Thus, a high resonant frequency of 1313.2 Hz is achieved along the X -axis while realizing a 212.7 \mum stroke. The Y -stage is designed with a large moving platform. Thus, it can carry the entire XZ -stage to conduct the long-range Y -axial scanning. As for the Z -stage, a PEA is adopted as the actuator to track the surface topography at a high rate. The advancement of the proposed scanner is demonstrated in AFM imaging. Excellent results in both the large-area coarse scanning and the high-speed, high-resolution fine scanning reveal the strong nanopositioning capability of this development.