Visible and infrared three-wavelength modulated multi-directional actuators

In recent years, light-guided robotic soft actuators have attracted intense scientific attention and rapidly developed, although it still remains challenging to precisely and reversibly modulate the moving directions and shape morphing modes of soft actuators with ease of stimulating operation. Here we report a strategy of building a multi-stimuli-responsive liquid crystal elastomer soft actuator system capable of performing not only multi-directional movement, but also different shape morphing modes. This strategy is based on the selective stimulation of specific domains of the hierarchical structured actuator through the modulation of three wavelength bands (520, 808, 980 nm) of light stimulus, which release the actuation system from light scanning position/direction restriction. Three near-infrared dual-wavelength modulated actuators and one visible/infrared tri-wavelength modulated multi-directional walker robot are demonstrated in this work. These devices have broad application prospects in robotic and biomimetic technology.