Bio-inspired thermal actuator for dynamic multispectral modulation from visible to microwave wavelengths

Abstract

With the rapid development of photoelectric technology, multispectral modulation materials are highly urgent to eliminate detection probability. However, it remains an extreme challenge to establish the platform for dynamic multispectral modulation from visible to microwave wavelengths. Herein, inspired by the lodging of plants, a thermal actuator (TA) was fabricated by gold layer coating MXene/Fe3O4@polyaniline (MFP) hybrids with the thermal-responsive polyurethane (TPU)-polycaprolactone (PCL) polymer blends. MFP exhibits excellent electromagnetic (EM) wave absorption due to excellent magnetic loss of Fe3O4, electricity loss of MXene, and dielectric loss of polyaniline, respectively. By applying an external thermal field, TA can change the shape from a lodging state to a vertical state due to the shape memory effect of TPU-PCL composite, which endows the TA with an excellent dynamic multispectral modulation ability. In detail, TA achieves a color change from yellow to black in the visible region, a transformation from high reflectance to high emittance in the infrared (IR) region, and a reflection loss (RL) modulation of 54.7 dB in the microwave region. Moreover, the TA exhibits excellent extensibility and shape reconfigurability. It is anticipated that the developed TA may serve as a guide for designing dynamic multispectral camouflage materials.