Table 2 Summary of structural color actuators based on CNCs
Material | Stimuli | Mechanism | Actuation | Structural color | Sensitivity | Response time | Ref. |
|---|---|---|---|---|---|---|---|
CNCs/PEGDA and PA-6 sandwiched structure | Humidity | Asymmetric pitch expansion between two layers | Flat to bending/twisting | Green to red (515–735 nm) | 80% RH, 25 °C | 5 s | |
CNCs/PEGDMA | Humidity | Asymmetric expansion between two sides | Flat to bending | Red to green with bending angle increase | Moisture 20 µL s−1 | 4 s | |
Bilayer PF resin using CNCs as templates | Water | Asymmetric expansion between two layers | Curling to uncurling | Double reflection 390/560 nm–685/970 nm | Dip in water or water vapor | 10 s | |
PF resin doped with GO using CNCs as templates | Water | Asymmetric expansion; selective aldehyde treatment to program initial shape | Bending to unbending; 3D shapes to uncurling | 600–800 nm | Dip in water | 6–180 s | |
CNC/PU with AgNPs | Humidity and NIR light | Asymmetric expansion when exposed to humidity and NIR light | Flat to bending | Blue to red | RH 30% - 70% | Humidity: 9 s; NIR light: 16 s |
