Fast Light-Driven Curling Actuation Based on Agar-Chlorophyll Film

The advanced sensing and driving capabilities of soft actuators have been driven by a range of modern society's intelligent requirements. However, many traditional soft actuators do not account for biocompatibility and are challenging to decompose naturally, leading to significant issues related to resource waste and environmental pollution. Here, a promising light-driven curling actuator with excellent degradation performance is reported in this paper. This environmentally friendly film is made of agar and chlorophyll using solution mixing and spin coating method. This resulting film has the Janus structure and responds quickly to near infrared light (NIR) with the curling speed of 1 cm⁻¹ in 2 s due to uneven stress distribution caused by inhomogeneous thermal expansion. Interestingly, this agar-chlorophyll film has light-driven remote control and self-degradation functions. As a proof-of-concept application, circuit switches and soft grabbers based on agar-chlorophyll film are developed to enable not only remotely control of light circuit switch but also item transport control. Meanwhile, the agar-chlorophyll film can be degraded in the soil for 10 days without causing environmental pollution. We believe this biocompatible film soft actuator proposed in this paper can provide new insights for the development of intelligent soft robots and other artificial intelligence devices.