Fig. 13: Humidity/NIR light responsive structural color actuators based on CNCs.

a Schematic mechanism of the CNCs/PU bilayer composite film and its NIR light- and humidity-responsive actuation mechanisms. Photographs of a “mimosa” shaped CNCs/PU bilayer splaying and closing when exposed to (b) moisture and (c) NIR light. Reproduced with permission78. Copyright 2021, Wiley-VCH