Multi-modal self-sustained motions of a silicone oil paper disc on a surface driven by hot steam

Self-sustained locomotion, as a potent tool for tackling intricate problems and navigating diverse challenges, has made notable strides across various disciplines such as bionics, soft robotics, and energy harvesters, owing to its efficiency, resourcefulness, and flexibility. Nonetheless, single-mode self-sustained motion in varied environments is typically tailored to specific task requirements and lacks adaptability to environmental shifts. To address these limitations, this study aims to develop a multi-modal self-sustained system, in which, a silicone oil disc is placed on a surface with hot steam. Driven by the hot steam, the silicone oil disc can self-oscillate or self-tumble continuously on the supporting surface. Furthermore, we established a thermo-mechanical coupling model to predict the transitions among self-oscillation, self-tumbling, and static modes. Theoretical findings reveal that the frequency of the self-oscillation increases with an increase in temperature and radius. The theoretical predictions align well with experimental results. The silicone oil disc utilizes a suitable temperature field to achieve programmable deformation and exhibits multi-modal self-sustained motions, with the potential to harness geothermal and industrial waste heat, making it a versatile, cost-effective, and energy-efficient solution for autonomous robotics, thermal-mechanical conversion, and waste heat recovery.