A molybdenum-disulfide nanocomposite film-based stretchable triboelectric nanogenerator for wearable biomechanical energy harvesting and self-powered human motion monitoring

Triboelectric nanogenerators (TENGs) are receiving significant interest in the wearable electronics industry owing to their distinct ability to capture ambient energy, particularly from human endeavors. Because they can serve as renewable sources of energy and multifunctional sensing devices. Herein, a stretchable TENG (S-TENG) based on micropatterned fabric-coated molybdenum disulfide (MoS2) and an Ecoflex nanocomposite as the electron-acceptor layer is newly developed for harvesting biomechanical energy to power wearable electronics and enable self-powered sensing. Incorporating the MoS2 monolayer in the composite creates microchannels on the surfaces, improving the conductivity of the composite by facilitating ion transport. Moreover, the incorporation of the monolayer provides an additional triboelectric output by increasing the contact area, enhancing the dielectric constant, and modulating the surface charge density. The use of knitted fabric materials enhances the extensibility (230 %) of the composite film. A thorough investigation was conducted to assess the electric output performance, resulting in the attainment of a maximum peak power density of 11 W/m2. This power density is sufficient to provide electricity to a typical electronic equipment with low power consumption. Regarding passive sensing, the suggested S-TENG may be used as a pressure sensor, with a high sensitivity of 17.18 V/KPa. Furthermore, active sensing enables the identification of dynamic movements in the joints of the human body by establishing a relation between gestures and the corresponding electrical signals. This study presents an innovative approach for developing a wearable S-TENG that exhibits dual-mode energy-harvesting and sensing capabilities, including the use in biomedical applications and human-machine systems.