Promising Developments in Marine Applications With Artificial Muscles: Electrodeless Artificial Cilia Microfibers

Ionic polymer-metal composite artificial muscles have received great research attention in the development of robotic manipulators, advanced medical devices, and underwater propulsors, such as artificial fish fins. This is due to their unique properties of large deformation, fast dynamic response, low-power requirements, and the ability to operate in aquatic environments. Recently, locomotion of biological cells and microorganisms through unique motion of cilium (flagellum) has received great interest in the field of biomimetic robotics. It is envisioned that artificial cilia can be an effective strategy for maneuvering and sensing in small-scale bioinspired robotic systems. However, current actuators used for driving the robots are typically rigid, bulky in mechanism and electronics requirements producing some acoustic signatures, and difficult to miniaturize. Herein, we report biomimetic, wirelessly driven, electroactive polymer (EAP) microfibers that actuate in an aqueous medium when subjected to an external electric field of <5 V/mm, which can be realized to create cilia-based robotic systems for aquatic applications. Initial development and manufacturing of these systems is presented in this paper. The EAP fibers are fabricated from ionic polymer precursor resin through melt-drawing process and have a circular cross-section with a diameter of 30-70 mu m. When properly activated and subjected to an electric field with switching polarity, the EAP fibers exhibit cyclic actuation with adequate response time (0.05-5 Hz). The experimental results are presented and discussed to demonstrate the performance and feasibility of biomimetic cilia-based microactuators. Prospective bioinspired applications of the artificial muscle cilia-based system in marine operations are also discussed.