Connotation, Research Status and Prospect of Tribovoltaic Effect

This study explores the tribovoltaic effect and its applications in energy harvesting and smart sensors. The tribovoltaic effect occurs when a sliding motion at a semiconductor heterojunction interface generates friction, which excites electron−hole pairs at the interface. Under the influence of an electric field at the semiconductor interface, these electron−hole pairs undergo directional migration, generating a direct current (DC), a process referred to as the tribovoltaic effect. Devices that harvest mechanical energy based on the tribovoltaic effect are known as tribovoltaic nanogenerators (TVNGs). TVNGs can directly output DC and exhibit low-impedance output characteristics, making them a subject of widespread interest. This paper first introduces the meaning of the tribovoltaic effect and summarizes the key scientific issues involved in its research: the mechanisms of electron−hole pair excitation and the formation of the interface electric field. These issues are critical for understanding the potential of the tribovoltaic effect and for optimizing the performance of TVNGs. Specifically, this research identified that the interaction effect in energy harvesting and smart sensing, with a particular focus on optimizing the TVNG performance. This study discusses the relationship between semiconductor properties and frictional forces that play a significant role in the excitation of electron−hole pairs, while the interface electric field is crucial for the separation and migration of these carriers. Understanding these mechanisms is essential to improving the efficiency and stability of energy conversion in TVNGs. Next, this study explores the applications of the tribovoltaic energy transmission laws involved in the tribovoltaic effect and highlights several challenges, including tribological issues and surface/interface engineering problems. This study proposes that the asymmetry in the geometric structure of materials and friction-induced asymmetry at the interface can significantly contribute to the tribovoltaic effect. These factors were hypothesized to influence the output efficiency and performance of TVNGs, suggesting that a more thorough understanding and control of these variables are necessary to optimize the device performance. This study also emphasized the importance of surface modification techniques and the impact of material properties on the tribovoltaic effect. By altering the surface structure and interface properties of materials, for instance, through doping or chemical treatments, it is possible to enhance the energy-harvesting capacity of the tribovoltaic effect. Furthermore, this study suggests that advancements in tribological research, including the understanding of friction and wear at the interface, are essential for optimizing TVNGs for real-world applications. By improving the surface roughness, frictional behavior, and chemical interactions at the interface, it is possible to maximize the efficiency of the tribovoltaic energy conversion process. Finally, this study discusses future research directions for the tribovoltaic effect, predicting that its study will become increasingly diversified and intelligent. The future of tribovoltaic research will focus on material optimization, specifically enhancing the stability, output power, and durability of TVNGs. These advancements are expected to be key factors driving the development of TVNGs, enabling their widespread use in practical applications. The future of tribovoltaic technology also lies in its potential to play a critical role in smart sensors, environmental monitoring, and wearable devices, with applications extending to self-powered systems and energy-efficient technologies. By improving the material properties and optimizing the overall performance of TVNGs, the tribovoltaic effect is expected to contribute significantly to the development of next-generation energy-harvesting devices. In conclusion, the tribovoltaic effect holds great promise for energy harvesting and smart sensor applications. Future research efforts will focus on improving the performance, stability, and durability of TVNGs, which are crucial for their practical deployment in various industries. The ongoing advancements in materials science, surface engineering, and tribological research are essential for achieving these goals and ensuring the successful integration of tribovoltaic technology into real-world applications.