The advancement of wearable electronics and environmental awareness requires a wearable triboelectric nanogenerator (TENG) to feature the concepts of sustainability and environmental suitability. While most wearable TENGs are developed based on complex surface modification approaches to avoid the necessity of a physical spacer, herein a nanogap TENG is fabricated based on surface self-modified sustainable polymer films. Compared with poly(lactic acid) (PLA)-based and polycaprolactone (PCL)-based TENGs, the polybutylene succinate (PBS)-based TENG shows the highest output performance, representing up to 3.5-fold that of the reported TENGs based on biodegradable materials with a 0-4 mm spacer, due to the higher content of the ester group and surface roughness resulting from the surface self-modification. The nanogap device is demonstrated as a pressure/angle sensor with acceptable sensitivity for use in health monitoring. More importantly, the environmental suitability of the triboelectric films in air, water, and phosphate buffered saline systems indicates their stability in natural water and saline environments. Moreover, the antibacterial property of the triboelectric films indicates future applications in wearable and implantable electronics. This work demonstrates the potential applications of a biocompatible and environmentally stable TENG in wearable electronics and biomedical systems.
Keywords: ester group; nanogap; surface self-modification; triboelectric nanogenerator; wearable electronics.