Development of two types of in-plane motion actuators with modular design and application to morphing wings

Abstract

This study explored the design, performance evaluation, and application of two types of in-plane motion actuators that were scalable to larger sizes—that is, the extension-type electrothermal actuator (ExACT) and retraction-type electrothermal actuator (ReACT). These actuators were based on the displacement amplification mechanism (DAM) principles and regularly arranged structures in mechanical metamaterials. A modular design approach allowed these actuators to be easily configured to the desired size and scaled to create large-scale in-plane motion actuators. Studies were conducted to assess the performance of the ExACT and ReACT, focusing on the actuator displacement and blocking force. The actuation displacements for the 3 × 1 ExACT and ReACT matrices were measured at 2.0 and 0.8 mm, respectively. Similarly, the blocking forces achieved by the actuator matrices were 2.24 and 3.78 N for the ExACT and ReACT, respectively. Subsequently, the ExACT and ReACT were applied to implement large deformable morphing wings, referred to as the ExMOW and ReMOW, respectively. These wings incorporated an additional thickness amplification mechanism resembling an elliptical bridge-type DAM. The wing thickness of the ExMOW increased by approximately one-third of its initial value, whereas that of the ReMOW decreased to approximately one-quarter of its original thickness.