Triboelectric nanogenerators (TENG) based on liquid-solid or solid-solid contact have attracted much attention in sensing applications recently. However, the stain caused from external environment and high friction over triboelectric interface are two important issues yet to be solved. To address these issues, a novel magnetic field assisted non-contact TENG is designed by driving the motion of ferrofluid in a sealed tube under an external magnetic field without direct contact. The as-designed TENG can separate the external mechanical motion from the inner triboelectric process, thereby solving the potential stain problem over the triboelectric interface from external environment. Furthermore, a lubricant oil layer is introduced between ferrofluid and substrate to construct a liquid–liquid triboelectric interface, which facilitates the sliding behavior of ferrofluid. This design helps to extend the range of linear relationship between triboelectric current peak value and the ferrofluid motion velocity over its surface, thereby breaking the motion velocity measurement limit of TENG as a velocity sensor. Finally, its potential application is demonstrated as a self-powered water/liquid level sensor. This work provides a novel type of non-contact TENG, and shows triboelectrification on liquid–liquid contact. The novel TENG could be further applied as a highly sensitive sensor in harsh environment.

基于液-固或固-固接触的摩擦电纳米发生器（TENG）最近在传感应用中引起了很多关注。然而，由外部环境引起的污点和摩擦电界面上的高摩擦是两个有待解决的重要问题。为了解决这些问题，设计了一种新颖的磁场辅助非接触式TENG，该方法通过在外部磁场下直接接触来驱动密封管中铁磁流体的运动来实现。设计的TENG可以将外部机械运动与内部摩擦电过程分开，从而解决了摩擦电界面与外部环境之间的潜在污染问题。此外，在铁磁流体和基材之间引入润滑油层，以构建液-液摩擦电界面，这有利于铁磁流体的滑动行为。这种设计有助于扩大摩擦电流峰值与铁磁流体在其表面上的运动速度之间的线性关系范围，从而打破了作为速度传感器的TENG的运动速度测量极限。最后，它的潜在应用被证明是一种自供电的水/液位传感器。这项工作提供了一种新型的非接触式TENG，并显示了液-液接触时的摩擦起电。新型TENG可以进一步用作恶劣环境中的高灵敏度传感器。它的潜在应用被证明是一种自供电的水/液位传感器。这项工作提供了一种新型的非接触式TENG，并显示了液-液接触时的摩擦起电。新型TENG可以进一步用作恶劣环境中的高灵敏度传感器。它的潜在应用被证明是一种自供电的水/液位传感器。这项工作提供了一种新型的非接触式TENG，并显示了液-液接触时的摩擦起电。新型TENG可以进一步用作恶劣环境中的高灵敏度传感器。