Plasticized electrohydraulic robot autopilots in the deep sea

Soft robots, with their compliant bodies, minimal environmental
disturbance, and ability to withstand ambient pressures, offer promising
solutions for deep-sea exploration. However, a common challenge of
stiffening in soft materials impairs their effective actuation in harsh
conditions. In this work, we integrated a liquid dielectric
plasticizer within an electrohydraulic soft robot, serving dual critical
functions as a softening agent to maintain the softness of the polymer
shell and an electrohydraulic fluid for efficient actuation. Additionally,
by utilizing the surrounding seawater as alternating electrodes, we
prevented charge retention in dielectric layers, enabling sustained
actuation performance. Field tests at depths of ~1360 meters, 3176 meters,
and ~4071 meters confirmed the robot’s ability to sense the environment,
navigate complex trajectories, and locomotor capabilities to withstand
unsteady disturbances. Our work offers a generalized and straightforward
framework for developing soft materials tailored for deep-sea
applications, paving the way for soft robots to execute real-world
missions.