Cover Image Published on Advanced Functional Material
Our research recently got featured as Front Cover Image in Advanced Functional Materials. Triboelectric nanogenerators (TENGs), which operate in contactless mode and avoid physical contact, are highly attractive for self-powered sensor systems aiming to achieve long-term reliable operation and reduce rubbing friction. Herein, an ultra-flexible and high-performance contactless double-layer TENG (CDL-TENG) is first designed and fabricated using a metal–organic framework-based cobalt nanoporous carbon (Co-NPC)/Ecoflex with MXene/Ecoflex nanocomposite layer for self-powered sensor applications. The porous structure of the Co-NPC provides a high-surface-area of the nanocomposite and the charge storage layer of the MXene/Ecoflex nanocomposite accumulates more negative charge to improve the functionality of the CDL-TENG two and three times, respectively. Compared with Ecoflex film-based TENGs, the fabricated CDL-TENG exhibits an eight-fold slower decay rate owing to charge trapping characteristics, which were confirmed by surface potential measurements. The CDL-TENG shows excellent humidity and acceleration sensitivity of about 0.3 V/% and 2.06 Vs2 m−1. The CDL-TENG also offers non-contact position detection performance in the 20 cm range. Furthermore, the CDL-TENG is successfully integrated with mobile-vehicles and an intelligent robot to perform obstacle and human-motion detection. Finally, a contactless door-lock password authentication system was demonstrated. These multifunctional benefits make it useful for numerous applications, including artificial intelligence, human-machine interfaces, and self-powered sensors.