Textile triboelectric nanogenerators for self-powered biomonitoring

Biomonitoring has played an increasingly important role in improving the quality of healthcare in recent years, but limitations in power supply and wearability, as well as the rise of the Internet of Things (IoT) have called for the development of a new type of device to provide biomonitoring on a daily basis. While the introduction of triboelectric nanogenerators (TENGs) has begun to solve these issues by providing sustainably powered biomonitoring, textile-based TENGs (tTENGs) take a more pervasive approach by integrating this technology into commonly worn textiles. tTENGs are particularly unique as they offer an inexpensive alternative for biomonitoring; the high breathability, comfort, and scalability inherent to tTENGs' woven structures have made them increasingly convenient for human application. This review begins by highlighting novel material configurations of tTENGs and their advantages for biomonitoring. We then discuss various wearable tTENG devices that have been adapted for constant cardiovascular and respiratory monitoring, pertinent to those suffering from diseases in these organ systems. Transitioning into the biomechanical aspect of the human body, we explore tTENG configurations integrated for upper body and gait motion sensing. At the same time, with many people suffering from sleep disorders, we examine tTENGs that monitor the quality of sleep of an individual. Lastly, on a more molecular level, we examine the application of tTENGs for monitoring biochemical fluctuations, such as sweat. Finally, we discuss the future research directions for the field, in particular regarding personalized healthcare propelled by tTENGs.