Flexible,Multifunctional, Magnetically Actuated Nanocomposite Films

Filler nanoparticles greatly enhance the performance of polymers and minimize filler content in the resulting nanocomposites. At the same time, they challenge the manufacturing of such nanocomposites by filler agglomeration and non‐uniform spatial distribution. Here, multifunctional nanocomposite films are made by capitalizing on flame‐synthesis of ceramic or metal filler nanoparticles followed by rapid, in situ deposition on sacrificial substrates, resulting in a filler film with controlled porosity. The polymer is then spin‐coated on the porous film that retained its stochastic but uniform structure, resulting in nanocomposites with homogeneous filler distribution and high filler‐loading. By sequential repetition of this procedure, sophisticated, multilayer, free‐standing, plasmonic‐ (Ag‐Fe₂O₃) and phosphorescent‐superparamagnetic (Y₂O₃:Eu³⁺‐ Fe₂O₃) actuators are made by precisely tuning the polymer thickness between each functional nanostructured layer. These actuators are quite flexible, have fast response times, and exhibit superior superparamagnetism due to their high filler content and homogeneous spatial distribution.