Construction of anisotropic near-infrared luminescent elastomers via magnetic orientation

We here report a Yb-containing Near-Infrared hybrid elastomer with anisotropic mechanical behavior as well as anisotropic luminescent performance, which is constructed by aligning the superparamagnetic nanoparticle coated alumina (Fe/Al 2 O 3 ) platelets with a magnetic field, then the oriented structure is fixed by in situ evaporation. Because the mechanical reinforcement of aligned Fe/Al 2 O 3 platelets to the polymeric elastomer is anisotropic, the mechanical strength parallel to the magnetic field is much higher than that of perpendicular to the magnetic field. Meanwhile, the hybrid elastomer also shows anisotropic NIR luminescence behavior, since the “shading effect” of the aligned Fe/Al 2 O 3 platelets on the Yb 3+ emitting centers is orientation-dependent. The method we report here may have great potentials in anisotropic sensing and physiological signal transduction , etc., which are essential for electronic skin and smart actuator.