This thesis investigates a low-voltage serial digital actuator, generating high-precision and wide-range displacement required for digital communication devices. The present actuator, composed of serially interconnected low-voltage unit actuators, accumulates unit displacements asynchronously for a wide-range displacement.
We design, analyze, and fabricate a prototype, serially interconnecting 10 unit actuators, to achieve displacement range of 30μm using 5V signal. The unit actuator consists of two pairs of parallel electrodes with stoppers and two pairs of serpentine springs. The stoppers, defining unit displacement, are designed not to accumulate the unit displacement precisions but for the total displacement precision to depend on the last unit displacement precision. The gravity center of parallel electrodes is located in the opposite side to that of serpentine springs with respect to the anchor, thus reducing the deflection due to total actuator mass.
The designed prototype is fabricated by single mask process. In the experimental study, we find that the fabricated actuator produces a wide-range displacement of 28.44±0.02μm at the minimum operating voltage of 4.47±0.07V. The measured total displacement precision of 37.94±6.26nm shows that the actuator does not accumulate the unit displacement precision of 36.0±17.7nm. The fabricated actuator achieves the ratio of displacement range to operating voltage, 6.36μm/V, and the ratio of displacement range to precision, 749.6, showing the improvement of performance at 162.8% and 49.9%, respectively, compared to the previous work[3,4]. We experimentally verify the potential for low-voltage, wide-range, and high-precision actuators in the digital communication devices.