Improved triboelectrification effect by bendable and slidable fish-scale-like microstructures

Improving the triboelectrification effect between tribo-materials is fundamentally important for advancing the booming community of triboelectric nanogenerators (TENGs) and self-powered sensors. Microstructures played key roles in improving the triboelectrification effect, however, the uprightness of commonly used microstructures always limited the triboelectrification to interfaces between the tops of microstructures and opposite tribo-films during vertical contact/separation processes. In this study, bendable and slidable fish-scale-like microstructures were developed to surpass the limitations by extending the triboelectric interfaces from their tops to their sidewalls, taking the advantages of bending and sliding movements. Based on the fish-scale-like microstructures, the as-prepared TENGs delivered open-circuit voltages reaching up to 470 V and a short-circuit current density of 45 mu A/cm(2). These values were two-fold higher than those obtained with vertical microstructures under the same testing conditions. The as-assembled self-powered pressure sensors based on fish-scale-like microstructures delivered linear measurement ranges reaching up to 42 kPa, low detection limit of 10 mPa, high sensitivity of 1.03 mV/Pa, and ultrafast response of 0.1 ms. These features were significantly enhanced when compared to those of vertical microstructures. More importantly, we also developed a straightforward and low-cost duplication method for fabricating the fish-scale-like microstructures, which are easily achievable for fabricating the high-performance TENGs or self-powered pressure sensors.