Hyeong-Joon Joo, Christoph Keplinger et. al., Science Advances, 2023 []

Underwater devices are critical for environmental applications. However, existing prototypes typically use bulky, noisy actuators and limited configurations. Consequently, they struggle to ensure noise-free and gentle interactions with underwater species when realizing practical functions.

In this project, we developed a jellyfish-like robotic platform enabled by a synergy of electrohydraulic actuators and a hybrid structure of rigid and soft components. Our 16-cm-diameter noise-free prototype could control the fluid flow to propel while manipulating objects to be kept beneath its body without physical contact, thereby enabling safer interactions. Its speed against gravity was up to 6.1 cm/s, substantially quicker than other examples in literature, while only requiring a low input power of around 100 mW. We further demonstrated contact-based object manipulation, fluidic mixing, shape adaptation, steering, wireless swimming, and cooperation of two to three robots.