Actuation performances of DMMLA with three working modes. Electromagnetic motion: (a) measured speed with different setting speed while the insert figure (i) shows in the log format and the insert figure (ii) shows the relationship of displacement vs. time. Piezoelectric step motion: (b) velocity under the driving voltage at different frequency; (c) velocity under different load and frequency. Piezoelectric servomotion: (d) test setup; (e) step voltage mode; (f) piezoelectric servomode under rectangular voltage, and the repeatable minimum step motion is as low as 0-2 nm. Note that the shifting is caused by circumstance vibration noise.