Exhaling‐Driven Hydroelectric Nanogenerators for Stand‐Alone Nonmechanical Breath Analyzing

Abstract The analysis of exhaled breath is an increasingly important role in the provision of security and in the management of personal healthcare. The development of self‐powered, reliable, miniature low cost and noninvasive devices is fundamental to practical applications. However, most state‐of‐the‐art self‐powered systems are incorporating mechanical nanogenerators, which would promote contact failures of electronics and limit minimization of the monitoring system. This work outlines a new solution to this problem based on a self‐powered breath analyzer integrated with a hydroelectric nanogenerator (HENG), in which the nanogenerator extracts electrical power from biochemical energy. The output signal from the sensor in this device is highly sensitive to the concentration of ethanol exhaled in breath down to low detection limitation of 50 ppm. A high dynamic range is observed whereby a signal response of ≈80% relative to peak value is obtained under the exposure to gas containing 100 ppm of ethanol. Unlike conventional self‐powered breathing analyzers based on piezoelectric or triboelectric nanogenerators, mechanical vibrations are eliminated. The availability of this compact breath analyzer provides a new detection regime for gas sensing, and should facilitate the design of a wide range of self‐powered systems incorporated in the next generation of innovative electronic devices.