Multi-scale metal mesh based triboelectric nanogenerator for mechanical energy harvesting and respiratory monitoring

Abstract With the rapid growth of wearable and portable electronics, triboelectric nanogenerator (TENG) has shown great potential to dramatically improve our daily life as self-powered sensors in energy harvesting and human motion monitoring. In this study, we propose a multi-scale metal mesh electrode (MME) based TENG in low-processing cost with superior output performance and durability. MME is fabricated via controllable, convenient and cost-effective alloying-dealloying method to enhance the high specific contacting surface as positive electrode. Owing to the synergistic effect of micro and nanostructures on MME, the output performance of TENG can be increased evidently. Various fabrication processes, including electroplating time, corrosive time and corrosive solution, are investigated to rich the surface nanostructures and better explore the effect of manufacturing parameters. The results show that MME based TENGs generate the maximum output voltage of 175.77 V at a frequency of 4 Hz and vertical force of 15 N in compressing-releasing operations, which is 4 times larger than that of copper film electrode, while the corresponding power density is about 0.85 W/m2. To demonstrate the practical application, TENG can be integrated in breathing valve mask as respiratory monitoring sensor to detect real-time respiratory rate, respiration intensity within different breath conditions, and realize breath identification during sound production. Overall, this work expands the design and fabrication strategy for TENG positive electrode and opens a potential application for self-powered wearable electronics in human healthcare monitoring and multifunctional intelligent sensors.