Novel thermal-induced anisotropic conductivity film and descendable 3D pipe or 2D + 3D architectures

In this study, a brand-new thermal-induced anisotropic conductivity film (TACF) is developed by using VO₂ with magnetism and semiconductor-to-metal phase transition to generate thermal-induced conductivity, and thus a new concept of thermal-induced anisotropic conductivity is advanced. [polymethyl methacrylate (PMMA)]//[VO₂/PMMA] Janus ribbon used as microscopic fabricating unit is orientationally aligned to create TACF via parallel electrospinning. A well-designed dual strategy of strengthening both conductivity in the conductive direction and insulation in the insulating direction to improve conductive anisotropism of film is realized by using the Janus ribbon with two micro-partitions. Upon heating, TACF exhibits strong conduction along the length direction of Janus ribbons (i.e. conductive direction) owing to VO₂ in metallic state to form conductive networks in VO₂/PMMA ribbons and intense insulation along the width direction of Janus ribbons (i.e. insulating direction) owing to introduction of insulating PMMA ribbons, achieving high thermal-induced conductive anisotropy. The anisotropic degree and paramagnetism of TACF are adjustable by modulating VO₂ contents and heating temperatures. TACF exhibits strong thermal-induced conductive anisotropic degree of 10⁴ at 80 °C. Meanwhile, the paramagnetism of TACF at 80 °C is four times higher than that at 25 °C. Two-dimensional (2D) TACF is curled into three-dimensional (3D) pipes and 2D plus 3D (2D + 3D) architectures, achieving convenient and cross-dimensional preparation of 3D or 2D + 3D thermal-induced anisotropic conductive materials from TACF. The descendable 3D pipes and 2D + 3D architectures exhibit similar performances as TACF. As applicative demonstrations, TACF, 3D pipes and 2D + 3D architectures display reliable conductive interconnection and anisotropic conduction in microcircuits upon heating.