Photomodulated Tricolor-Changing Artificial Flowers

Abstract

In nature, many flowers can open their petals into blooming flowers or furl them into buds and simultaneously alter the petal colors under the precise control of light, temperature, pH, humidity, or other environmental stimuli. Inspired by this fascinating natural phenomenon, here we report a two-spiropyran-unit-functionalized, monodomain/polydomain bilayer-structured liquid crystal elastomer strategy to fabricate an ultraviolet, green, and near-infrared trilight-modulated tricolor-changing flower mimic soft actuator. Relying on a combination of photochromic effect, thermochromic effect, pigment blending effect, photothermal conversion effect, and gradient stress effect, this flower mimic material can furl or open it “petals” under the on/off stimulation of near-infrared light and meanwhile possess a tristable showy color switch system which is tunable through varying the wavelength band (365, 520, and 808 nm) of light stimuli. Such a material has wide application prospects in camouflage materials, control devices, and biomimetic devices.