Ocean current energy harvester is a promising infrastructure to achieve self-powered marine wireless sensing system. This study proposes and investigates an underwater flag-like Triboelectric Nanogenerator (UF-TENG) based on the flow-induced vibration. The UF-TENG consists of two conductive ink-coated polyethylene terephthalate membranes and one strip of poly tetra fluoroethylene membrane with their edges sealed up by a waterproof PTFE tape. In this way, the triboelectric layers are prevented from contacting water. It is verified that the vortex street induced by a cylinder enhances the vibration of the UF-TENG. The low velocity startup enables the UF-TENG to harvest extremely low-velocity ocean current energy, e.g., presently achieving 0.133 m/s as the critical startup velocity. The proposed UF-TENG has a simpler structure and better low velocity performance when comparing with electromagnetic generators and piezoelectric generators. Parametric studies are conducted to evaluate the influence of geometrical parameters of the UF-TENG on the vibration behavior and output performance. It is demonstrated that the underwater electrical appliance can be powered by parallel UF-TENG units. The present UF-TENG is a more cost-effective and more accessible hydroelectric technology to utilize the renewable ocean current for powering sensors or micro electric appliances in Internet of Things.

洋流能量收集器是实现自供电海洋无线传感系统的有前途的基础设施。本研究提出并研究了一种基于流致振动的水下旗状摩擦纳米发电机（UF-TENG）。UF-TENG 由两个导电油墨涂层的聚对苯二甲酸乙二醇酯膜和一条聚四氟乙烯膜组成，它们的边缘由防水 PTFE 胶带密封。以此方式，防止摩擦电层接触水。经证实，圆柱引起的涡街增强了 UF-TENG 的振动。低速启动使 UF-TENG 能够收集极低速的洋流能量，例如，目前达到 0.133 m/s 作为临界启动速度。与电磁发电机和压电发电机相比，所提出的 UF-TENG 具有更简单的结构和更好的低速性能。进行参数研究以评估 UF-TENG 的几何参数对振动行为和输出性能的影响。结果表明，水下电器可以由并联的 UF-TENG 单元供电。目前的 UF-TENG 是一种更具成本效益和更容易获得的水力发电技术，可利用可再生洋流为物联网中的传感器或微型电器供电。结果表明，水下电器可以由并联的 UF-TENG 单元供电。目前的 UF-TENG 是一种更具成本效益和更容易获得的水力发电技术，可利用可再生洋流为物联网中的传感器或微型电器供电。结果表明，水下电器可以由并联的 UF-TENG 单元供电。目前的 UF-TENG 是一种更具成本效益和更容易获得的水力发电技术，可利用可再生洋流为物联网中的传感器或微型电器供电。