In this manuscript, we describe a photo-responsive
dual-layer polysiloxane-based liquid crystal elastomer (LCE) soft actuator with
switchable handedness of helical curling motions. Benefited from the embedded
organic near-infrared (NIR) absorbing dye, the LCE ribbon can perform an
impressive one-handed helical curling deformation under NIR light irradiation,
meanwhile execute another-handed helical curling deformation under ultraviolet
(UV) light irradiation due to the trans-cis isomerization effect of azobenzene. This
work demonstrates that the handedness of helical curling motions of LCE soft
actuators can be reversibly altered by modulating the wavelength band of light
stimuli (UV vs. NIR), which might have potential applications in control
devices.