Soft Material Actuation and Shape-Change Through Ultrasonic Atomization

Abstract

Remotely operated vehicles (ROV) conduct tasks that are generally dangerous or ineffective for humans, such as exploring and surveying the ocean for extended periods of time. Current underwater ROVs are complex assemblies of mostly rigid components designed for interacting with the environment, locomotion, and buoyancy control. Several recent studies introduced methods to replace these components with soft actuators to improve their performance. This study shows that actuation through ultrasonic atomization is capable of inflating a soft structure that can potentially replace traditional variable buoyancy systems. Ultrasonic waves were applied to a soft hollow structure that was partially filled with ethanol. The ultrasonic waves propagated through the wall of the structure and atomized ethanol into small vapor droplets. The liquid-togas phase transformation of the small droplets inflated the structure and controlled the buoyancy of the system. In this study, the volumetric change of the soft structure was analyzed underwater, and a simple system to control buoyancy was demonstrated