Fig. 4: Experimental characterization of the optimal XYθ_z nanopositioner’s positioning resolutions and an “NTU” trajectory showcase.

A Positioning resolutions of the XYθ_z nanopositioner. (i) showed that the robot was able to track a series of step responses that continuously increment or decrement 13 nm along the X-axis. Likewise, (ii) and (iii) showed that the robot could track a series of step responses that continuously increment or decrement 14 nm along the Y-axis and 1.3 µrad about the Z-axis, respectively. B The end-effector of the robot was commanded to trace an “NTU” trajectory across different length scales in the XY plane. The letters “N”, “T” and “U” were in millimeters, micrometers and nanometers, respectively. When the robot was tracing the “N” letter, its end-effector’s orientation was rotated to –2° about the Z-axis. The orientation of the end-effector was rotated to +2° about the Z-axis when the robot was tracing the “T” and “U” letters. On the extreme right, the zoom-in of the “U” letter indicated the robot’s positioning resolution in this trajectory (~14 nm).