Wang Jiaqi, Meng Cuiling, Gu Qian, Tseng Man Chun, Tang Shu Tuen, Kwok Hoi Sing, Cheng Jia, Zi Yunlong
Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China.
Shun Hing Institute of Advanced Engineering, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China.
ACS Nano. 2020 Mar 24;14(3):3630-3639. doi: 10.1021/acsnano.0c00107. Epub 2020 Feb 26.
Self-powered smart windows are desirable with the expectations of their energy-saving, weather-independent, user-controllable, and miniature performance. Recently developed solar- or thermal-powered smart windows largely depend on the weather conditions and have an extremely slow response, and only a certain portion of the saved energy can be utilized by the external circuit for mode conversion. In this work, a self-powered normally transparent smart window was developed by the conjunction of a rotary freestanding sliding triboelectric nanogenerator (RFS-TENG) and a polymer network liquid crystal (PNLC) cell. To fabricate the PNLC cell, the alignment layer with randomly distributed microdomains was constructed to encapsulate a mixture of LC polymers and nematic LCs. The opacity of the smart window exposed to an alternating electric field was considerably improved owing to the embedded microdomains and a dense web of LC polymers. The ultrahigh haziness greatly alleviates the charge density required for the LC actuation and thus enables the driving by the TENG where the charge amount is usually limited. The RFS-TENG was elaborately designed with six periodic bent triboelectric films and Ag electrodes, which presented an ultralow friction wear and met the frequency requirement to achieve the steady opacity. By harvesting the mechanical energies from ambient environments, the tribo-induced smart window can benefit a wide variety of fields, such as self-powered sunroofs, wind-driven smart farming systems .
自供电智能窗因其节能、不受天气影响、用户可控和微型化性能而备受期待。最近开发的太阳能或热驱动智能窗在很大程度上依赖于天气条件，响应极其缓慢，并且只有一部分节省的能量可以被外部电路用于模式转换。在这项工作中，通过旋转独立滑动摩擦纳米发电机（RFS-TENG）和聚合物网络液晶（PNLC）单元相结合，开发了一种自供电的常透明智能窗。为了制造PNLC单元，构建了具有随机分布微区的取向层，以封装LC聚合物和向列型液晶的混合物。由于嵌入的微区和密集的LC聚合物网络，暴露于交变电场的智能窗的不透明度得到了显著提高。超高雾度极大地减轻了LC驱动所需的电荷密度，从而能够由电荷数量通常有限的TENG驱动。RFS-TENG精心设计了六个周期性弯曲的摩擦电薄膜和银电极，具有超低的摩擦磨损，满足实现稳定不透明度的频率要求。通过从周围环境中收集机械能，摩擦诱导智能窗可惠及广泛的领域，如自供电天窗、风力驱动的智能农业系统。
