Light-driven soft actuator with integrated fiber force sensing based on GO/PDMS-AuNBPs composite film

Light-driven soft actuators have attracted significant attention for applications in soft robotics. Precise quantification of the grasping force is essential for the accurate manipulation of target objects with varying mechanical properties. Here, we present a light-driven soft actuator that integrates an ultrathin tapered optical waveguide and a high-sensitivity optical fiber force-sensing probe into a graphene oxide/polydimethylsiloxane‑gold nanobipyramids (GO/PDMS-AuNBPs) composite film, enabling grasping-force sensing and power-dependent actuation. The ultrathin tapered waveguide is embedded between the PDMS/GO films that provide high energy density and optical coupling efficiency. The actuator achieves a large bending angle and a fast response, reaching a bending angle of 155° within 8 s. A highly sensitive optical fiber force-sensing probe with the sandwiched structure is fixed on the actuator surface to realize a wide-range force monitoring. The mechanical response of the actuator can be monitored through the integrated fiber probe and tuned by modulating the driving laser power. The proposed soft actuator was demonstrated to stably grasp and transfer lightweight targets in the milligram range under the current experimental conditions. The light-driven soft actuator integrated with an optical fiber-sensing probe offers a new perspective for the development of light-driven soft robotic systems.