Endowing Soft Photo-Actuators with Intelligence

Stimuli-responsive materials change their physical or chemical properties in response to external stimuli just like they have thoughts, which plays an important role in developing intelligent living systems for human beings. Thereto, recently developed soft photo-actuators based on functional polymers demonstrate their capabilities of performing diverse mechanical movements, such as walking, swimming, and gripping, under the control of the light stimulus. Different from conventional electric power-driven robots, soft photo-actuators can complete the procedures of sensing light signals and converting them into mechanical work simultaneously without complex serial-parallel circuits. They are promising candidates for soft robotics due to their advantages in miniaturization, controllability, and functionality. Herein, the progress of soft photo-actuators regarding their materials structure and working mechanisms and the design strategy for a robust and intelligent system are elucidated. In addition, the significance of introducing self-feedback loops to the actuator in realizing automatic and continuous motion is also emphasized. In future, soft photo-actuators will be utilized in biomimetic or medical systems if their intelligent performances are further improved.