Fig. 3: Disinfection performance of the V-TENG-powered RV-disinfection method for air-transmitted microbes.

a–c Disinfection efficiency for Escherichia coli (E. coli; Gram-negative bacteria (a)), Bacillus subtilis (B. subtilis; Gram-positive bacteria (b)), and MS2 (virus; c) using the RV-disinfection method at various airflow rates (from 0.5 to 2 m/s) powered by V-TENGs. d–f Plating results showing the concentration of E. coli (d), B. subtilis (e), and MS2 (f) after passing through RV-disinfection with or without the power from V-TENGs. g The disinfection performance of the RV-disinfection method for treating intermittent bacterial bioaerosols containing E. coli. The nebulizer with the feed solution was turned on (start) and then off (stop) for 5 min to generate an intermittent microbial bioaerosol and this periodically turning on and off leads to a periodic change of the microbial concentration. h Disinfection-performance comparison of RV-disinfection method using values in the literature describing other air disinfection methods. The plot shows speed of airflow with respect to treatment time for all the air disinfection methods in the comparison: (1) RV-disinfection (this work; complete disinfection, >4.1 log removal), (2) metal-organic-framework-modified filter (ref. ⁹; complete disinfection, >4.0 log removal), (3) TiO₂-film (ref. ¹²; 0.9 log removal), (4) ZnO-Al₂O₃-filter (ref. ¹³; 1.7 log removal), (5) Fe-mesh (ref. ¹⁵; 7.0 log removal), (6) vacuum UV (ref. ¹⁰; 1.2 log removal), and (7) UV-LED (ref. ¹¹; 2.5 log removal). Details of the conditions for the disinfection experiments (applied materials, disinfection mechanisms, energy demands, and microbial strain) are given in Supplementary Table 1. The final inactivation efficiencies are limited by the initial microbial concentration. In (a–g), V-TENGs were operated at a constant amplitude (500 μm) and vibration frequency (30 Hz), and in (d–g), the airflow rate was fixed at 2 m/s. Dashed lines indicate that all microbes are inactivated, and no live microbes can be detected. The error bars represent the standard deviation of three replicate measurements.