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

Abstract

This paper presents the design, fabrication, and characterization of a new serial digital actuator, achieving an improvement in range-to-precision and range-to-voltage performance. We propose a weight-balanced design for the serial actuators with serpentine springs with a serial arrangement of unit digital actuators. We have measured the displacement range, precision, and drive voltage of unit and serial actuation at 1 Hz. The serial digital actuators produce a full-range displacement of 28.44 +/- 0.02 mu m, accumulating unit displacements of 2.8 +/- 0.5 mu m at an operating voltage of 4.47 +/- 0.07 V. In addition, the serial digital actuators that have a displacement precision of 37.94 +/- 6.26 nm do not accumulate the displacement errors of the unit actuators, i. e., 36.0 +/- 17.7 nm. We experimentally verify that the serial digital actuators achieve a range-to-squared-voltage ratio of 1.423 mu m/V(2) and a range-to-precision ratio of 749.6.