Four-waveband-modulated liquid crystal elastomer (LCE) actuators for soft robotics based on optical wavelength selective actuation of dye-doped LCE materials

To promote the development of precise photo control of liquid crystal elastomer (LCE) actuators with ease of stimulating operations, a study on the wavelength-selective actuation of LCE actuators using light-absorbing dyes with special optical waveband absorption properties is performed. LCE materials doped by visible light-absorbing dyes of different absorption bands demonstrated good functionality for selective actuation through the modulation of visible light wavelength bands, and the selective actuation of four wavebands on dye-doped LCE actuators was achieved for the first time. On the basis of the dye-doped LCE actuators, a crawling soft robot was constructed, capable of achieving excellent performance in terms of four-directional photo-actuated motion by filtering light irradiation from the same quasi-daylight source into four different wavelength bands. It could move to any destination through the appropriate combinations of these four directional movements or parts of these four directional movements. Our work further developed technologies for the selective photo actuation of LCE actuators and expanded the potential of quasi-daylight and even natural sunlight for precise and convenient photo control of LCE actuators.