The schematic diagram and characterization image of the preparation process of micropillar array and magnetic-field-oriented m-BNNS composite film. (a) The preparation process of few-layer BNNS and BNNS magnetization; (b) microstructure (imprinting process) and magnetic-field-oriented alignment process of m-BNNS/PDMS composite films; (c) photos of magnetized m-BNNS/PDMS adsorbed by a magnet; (d) optical visualization and flexible display of m-BNNS/PDMS composite membrane; (e) optical microscope characterization of m-BNNS/PDMS composite film.