Researchers have created fiber-based soft robots with advanced motion control that integrate other functionalities, such as electric and optical sensing and targeted delivery of fluids. (Credit: Alain Herzog)

Combining advances in the development of functional fibers with developments in smart robotics, researchers have created multifunctional catheter-shaped soft robots that, when used as catheters, could be remotely guided to their destination, or possibly even find their own way through semi-autonomous control.

The researchers created the fibers with the thermal drawing process commonly used to produce fiber optic cables, similar to pulling a long string of cheese from a fondue and letting it harden. Material choice was critical, with elastomers — elastic polymers that return to their original shape when stretched — the preferred candidate: In addition to being flexible, they are soft enough to minimize lesions of delicate body tissues.

To generate long fibers featuring multiple channels along their entire length, the researchers had to fine-tune the drawing process parameters. By getting the material properties, the drawing speed, and the temperature just right, the team could reliably produce the continuous channels, carefully arranged within the fibers at a micrometer scale, needed to give the fiber its robotic capabilities.