Biospinning of hierarchical fibers for a self-sensing actuator

Artificial muscles, skin, and flexible electronics all benefit from smart actuators. However, developing actuators with high self-driving/sensing capabilities, as well as the real-time feedback function, remains a difficult issue. Herein, we reported a hierarchical fiber actuator with a desirable function. The fiber actuator was created by parallel wet-spinning sodium alginate (SA) and polypyrene (PPy)/graphene oxide (GO) (PPy/GO), which was then twisted to form a hierarchical structure. The constructed hierarchical fiber actuator demonstrated IR irradiation (150 W) and humidity responsiveness (90RH%), as well as a real-time feedback function, allowing autonomous and remote control in difficult situations. Meanwhile, such fiber has a synergistic response to both IR and humidity, which have a strong linear relationship (y = -0.150x + 0.004 and y = -0.217x + 0.007), and can be used for remote controllable fixed-point transportation in complex environments as well as real-time detection feedback in fixed-point environments. The hierarchical fibers are easily incorporated into a variety of actuators and detecting devices, including a breathing sensor and a self-sensing weightlifter. In the field of artificial muscle functions, hierarchical fibers have the potential to be a significant building element for next-generation actuators.