Microsensor-Internalized Fibers as Autonomously Controllable Soft Actuators.

Despite their strengths in flexibility and miniaturization, the stable operation of soft actuators under ever-changing environmental and biological conditions is hindered by the lack of applicable methods using internal sensors to detect unintentional stimuli. Here, the integration of a microscale driving source and sensors in a single fiber via thermal drawing is presented as a strategy to scalably produce autonomously responsive, feedback-controllable soft actuators. The regulation of the input electrothermal stimuli via a closed loop control system that is based on completely coupled internal sensory components enables multimodal actuation of fiber-based actuators, which is further demonstrated through preservation of actuating conditions, actuation of selected devices in their bundles, and modulation of motion characteristics. The approach to manufacturing autonomously controllable soft actuators can expand applications of soft actuators in kaleidoscopic biomedical and bioengineering fields for transportation, robotics, and prosthetics.