Although the contact electrification (CE) (or usually called ‘triboelectrification’) effect has been known for over 2600 years, its scientific mechanism still remains debated after decades. Interest in studying CE has been recently revisited due to the invention of triboelectric nanogenerators (TENGs), which are the most effective approach for converting random, low-frequency mechanical energy (called high entropy energy) into electric power for distributed energy applications. This review is composed of three parts that are coherently linked, ranging from basic physics, through classical electrodynamics, to technological advances and engineering applications. First, the mechanisms of CE are studied for general cases involving solids, liquids and gas phases. Various physics models are presented to explain the fundamentals of CE by illustrating that electron transfer is the dominant mechanism for CE for solid–solid interfaces. Electron transfer also occurs in the CE at liquid–solid and liquid–liquid interfaces. An electron-cloud overlap model is proposed to explain CE in general. This electron transfer model is extended to liquid–solid interfaces, leading to a revision of the formation mechanism of the electric double layer at liquid–solid interfaces. Second, by adding a time-dependent polarization term P_s created by the CE-induced surface electrostatic charges in the displacement field D, we expand Maxwell’s equations to include both the medium polarizations due to electric field (P) and mechanical aggitation and medium boundary movement induced polarization term (P_s). From these, the output power, electromagnetic (EM) behaviour and current transport equation for a TENG are systematically derived from first principles. A general solution is presented for the modified Maxwell’s equations, and analytical solutions for the output potential are provided for a few cases. The displacement current arising from ε∂E/∂t is responsible for EM waves, while the newly added term ∂P_s/∂t is responsible for energy and sensors. This work sets the standard theory for quantifying the performance and EM behaviour of TENGs in general. Finally, we review the applications of TENGs for harvesting all kinds of available mechanical energy that is wasted in our daily life, such as human motion, walking, vibration, mechanical triggering, rotating tires, wind, flowing water and more. A summary is provided about the applications of TENGs in energy science, environmental protection, wearable electronics, self-powered sensors, medical science, robotics and artificial intelligence.

尽管接触起电 (CE)（或通常称为“摩擦起电”）效应已为人所知 2600 多年，但几十年后其科学机制仍然存在争议。由于摩擦纳米发电机 (TENG) 的发明，最近人们重新审视了对 CE 的研究兴趣，摩擦纳米发电机 (TENG) 是将随机低频机械能（称为高熵能）转换为分布式能源应用电能的最有效方法。这篇综述由三个相互关联的部分组成，从基础物理学到经典电动力学，再到技术进步和工程应用。首先，研究了涉及固相、液相和气相的一般情况的 CE 机理。提出了各种物理模型来解释 CE 的基本原理，说明电子转移是固-固界面 CE 的主要机制。 CE 中的液-固和液-液界面也会发生电子转移。提出了电子云重叠模型来解释一般的CE。该电子转移模型扩展到液固界面，从而修正了液固界面双电层的形成机制。其次，通过在位移场D中添加由 CE 诱导的表面静电电荷产生的与时间相关的极化项P _s ，我们将麦克斯韦方程扩展为包括由于电场 ( P ) 和机械搅动以及介质边界引起的介质极化运动诱发极化项 ( P _s )。 由此，TENG 的输出功率、电磁 (EM) 行为和电流传输方程根据第一原理系统地导出。给出了修正麦克斯韦方程组的一般解，并针对几种情况提供了输出电势的解析解。由ε ∂ E /∂t 产生的位移电流负责电磁波，而新添加的项 ∂ P _s /∂t 负责能量和传感器。这项工作为量化 TENG 的性能和电磁行为奠定了标准理论。最后，我们回顾了 TENG 在收集日常生活中浪费的各种可用机械能方面的应用，例如人体运动、行走、振动、机械触发、旋转轮胎、风、流水等。总结了 TENG 在能源科学、环境保护、可穿戴电子产品、自供电传感器、医学、机器人和人工智能等领域的应用。