Serially-Connected Weight-Balanced Digital Actuators for Wide-Range, High-Precision, Low-Voltage Displacement Control

This paper presents the design, fabrication, and characterization of new serial digital actuators, achieving the improvement of the range-to-precision and range-to-voltage performance. We propose a weight-balanced design for the serial actuators with serpentine springs with serial arrangement of digital actuators. We have measured the displacement range, precision, and drive voltage at unit and serial actuation of 1Hz. The serial digital actuators produce a full range displacement of 28.44± 0.02μm, accumulating the unit displacement of 2.8±0.5μm at the operating voltage of 4.47±0.07V. In addition, the serial digital actuators having the displacement precision of 37.94±6.26nm do not accumulate the precision of the unit actuators, 36.0±17.7nm. We experimentally verify that the serial digital actuators achieve the range-to-squared-voltage ratio of 1.423μm/^V2and the range-to-precision ratio of 749.6.