阻抗渐变高介电钛酸钡/聚酰亚胺复合薄膜的设计与制备

人体皮肤与空气间在介电常数上有着失配性,可穿戴设备所用的材料需要与人体皮肤有良好的匹配性能,而单一的材料与结构已不能满足这种需求。利用原位聚合法合成了一系列钛酸钡(BaTiO_3)/聚酰亚胺(PI)混合溶液,通过逐层流延涂覆的方法设计制备了一种具有阻抗渐变性质的多层BaTiO_3/PI复合薄膜。结果表明:BaTiO_3纳米粒子可在复合薄膜中均匀分散,调节无机粒子的含量,能够有效地控制复合薄膜的介电常数在2.5~34.0之间变化;同时,BaTiO_3/PI复合薄膜对外加电场的频率具有不敏感性,也具有良好的力学性能,能够满足可穿戴设备对材料的要求。

Design and fabrication of high-dielectric BaTiO3/polyimide composite film with impedance gradient

The dielectric constant of human skin and air have a large mismatch. The materials used for wearable devices need to have a great matching performance with human shin, which can not be achieved by solo material and structure. By using the in-situ polymerization method, a series of barium titanate (BaTiO₃)/polyimide(PI) mixed solutions were synthesized. Then, by means of casting method step by step, a multilayer BaTiO₃/PI composite film with impedance gradient was designed and fabricated. The results show that BaTiO₃ nano-particles can distribute in the composite film uniformly. By adjusting the content of inorganic particles, the dielectric constant of prepared BaTiO₃/PI composite film can be controlled in the range of 2.5-34.0. Besides, BaTiO₃/PI composite film is insensible to the frequency of electric field and also has a good mechanical property, which can meet the requirements of wearable device materials.