Wrinkled Membrane-Integrated Flexible Actuator with Large Operating Displacement for Wearable Tactile Display

This paper reports a flexible actuator operating via a liquid-to-gas phase change transition, which is integrated with a wrinkled membrane to increase operating displacement. When the liquid phase change materials (PCM) vaporize into the gas, the volume of the PCM expands, causing the wrinkled membrane to spread. The wrinkled membrane exhibits superior extensibility compared to the flat membrane, resulting in an increased operating displacement of 740% under the same driving conditions. In the fabrication process, we create the wrinkled membrane by inducing the stress between adjacent membranes. The proposed method can be easily applied to multiple cells without using a mold. Furthermore, the operating displacement can be adjusted by controlling the driving voltage, and no significant deviation is observed in the transient curve of the actuator even after repeated actuation. The proposed actuator holds promising potential for applications in wearable tactile displays that require diverse operating displacements and a high operating speed.