A team from the University of California Santa Barbara has developed a robot that mimics how plant roots and vines move toward sources of moisture.

To mimic how plants guide their roots to sources of moisture, the 2 m long robot was composed of thin, flexible bags filled with a type of refrigerant called Novec 7000. The sleeve shaped bags were divided into 4.5 cm segments that accommodate the robot’s moves toward heat sources.

Model verification on a section of robot. The predicted shape is drawn in orange. Inset shows the infrared image of a similar test setup. Source: arXiv (2023). DOI: 10.48550/arxiv.2301.07362Model verification on a section of robot. The predicted shape is drawn in orange. Inset shows the infrared image of a similar test setup. Source: arXiv (2023). DOI: 10.48550/arxiv.2301.07362

According to the researchers, as the robot moves toward the heat source, the segments of the robot are adjusted with the side nearest the heat source growing shorter while the opposite side elongates.

Resembling a segmented worm, the robot is encouraged to move by temperature changes when the refrigerant starts to evaporate at 34° C.

The team tested the robot in various environments where it proved it could navigate around small objects, bending toward heat sources as well as extending and unfurling itself.

The researchers are eyeing the robot for applications such as firefighting, if armed with a hose that pumps water, and search and rescue missions.

The article detailing the robot, Thermotropic Vine-inspired Robots appears in the journal arXiv.

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