LCE-integrated soft skin for millimeter-scale steerable soft everting robots

Abstract

Soft everting robots grow their body from the tip via eversion, enabling minimal interaction with their surroundings. They can traverse complex environments by changing the growth direction via integrated steering mechanisms. However, it is challenging to miniaturize existing steering mechanisms and to achieve multiple bends while remaining fully soft. In this work, we present an approach to create millimeter-scale, steerable, and fully soft everting robots by functionalizing the robot skin with liquid crystal elastomer (LCE) actuators. This design enables large bending angles (>100°) at multiple points along the robot's length. We investigate the effects of internal pressure and actuator temperature as control inputs for steering and demonstrate the potential of our design for practical applications, such as surgical procedures and inspection tasks. Our results highlight the advantages of soft, functionalized skins and represent a step toward small, steerable, soft everting robots for applications in delicate and constrained environments.