An Ambidextrous STarfish-Inspired Exploration and Reconnaissance Robot (The ASTER-bot)

As more roboticists are turning to Nature for design inspiration, it is becoming increasingly apparent that multisystem-level investigations of biological processes can frequently lead to unexpected advances in the development of experimental research platforms. Inspired by these efforts, we present here a holistic approach to developing an autonomous starfish-inspired soft robot that embodies a number of key design, fabrication, and actuation principles. These key concepts include integrated and sequentially deployable magnetic tube feet for site-specific and reversible substrate attachment, individually addressable flexible arms, and highly efficient and self-contained fluidic engines. These individual features offer a level of synergistic motion control not previously seen in other starfish-inspired robots. For example, our bistable dome-like tube feet are capable of achieving high adhesion forces to ferrous surfaces and low removal forces. These tube feet are further integrated with a fluidic engine to drive the entire arm while maintaining the ability to accurately control the arm position with a 270° range of motion. Furthermore, the arm and fluidic engine are modular, allowing each of the five arms to be replaced in seconds or enabling the exploration of a variety of limb geometries. Through the incorporation of these different design elements, the ASTER-bot (named for its star-like body plan) is capable of locomotion on ferrous surfaces, above and below water, and on nonplanar surfaces. This article further describes the design, fabrication, and integration strategies and characterizes the energetic and locomotory performance of this pentaradial robotic prototype.