Ionogel-based, highly stretchable, transparent, durable triboelectric nanogenerators for energy harvesting and motion sensing over a wide temperature range

Hydrogel-based triboelectric nanogenerators (H-TENGs) have shown great promise in wearable electronics as soft, stretchable and sustainable power sources. However, H-TENGs can only be used in a narrow temperature range for a short duration due to freezing and evaporation of water. Here, an ionogel-based triboelectric nanogenerator (I-TENG) is designed to significantly broaden the application temperature range and duration while retaining all the superior properties of H-TENGs. The ionogel network constructed by dipole-dipole and ion-dipole interactions exhibits high stretchability (~800%) and ionic conductivity (1.1 mS cm−1). The corresponding I-TENG retains high stretchability (>400%), transparency (>90%), and anti-fatigue resistance (resisting 1000 cycles of 100% stretching) with stable electrical performance for 1 month. The I-TENG shows an instantaneous peak power density of 1.3 W m−2 and efficiently harvests biomechanical energy to drive an electronic watch. Additionally, the I-TENG serves as a self-powered human motion sensor to inspect the bending angle of an elbow. More importantly, the I-TENG retains high stretchability and electrical performance over a wide temperature range from −20 to 100 °C. This work provides a new strategy to design and tailor TENGs that will be very useful for diverse applications, including wearable electronics, electronic skin, and artificial intelligence.