Many
creatures have excellent control over their form, color, and
morphology, allowing them to respond to the interaction of environmental
stimuli better. Here, the bioinspired synergistic shape–color-switchable
actuators based on thermally induced shape-memory triethanolamine
cross-linked polyurethane (TEAPU) and thermochromic ionic liquids
(ILs) were prepared. The thermochromic ILs with various metalized
anions, including bis(1-butyl-3-methylimidazolium) tetrachloro nickelate
([Bmim]2[NiCl4]) and bis(1-butyl-3-methylimidazolium)
tetrachloride cobalt ([Bmim]2[CoCl4]), are investigated.
The actuators exhibit thermochromic response, as evidenced by a shift
in the color of the composites, which is due to the formation of the
tetrahedral complex MCl4
2– (M = Ni and
Co) after dehydration. The shape–color-switchable thermochromic
actuators have strong molecular interaction between TEAPU and ILs
and can mimic natural flowers and change the color and shape quickly
in a narrow temperature range (30–70 °C). In addition,
these thermochromic actuators can lift more than 50 times their weight
and withstand strains of more than 1100%. The results represent the
potential application in artificial muscle actuators and intelligent
camouflages.