Physically doped and printed elastomer films as flexible high-performance triboelectric nanogenerator for self-powered mechanoelectric sensor for recovering voice and monitoring heart rate

Flexible triboelectric nanogenerator (f-TENG) is usually fabricated from elastomer. However, elastomer is generally not as effective as fluorine or amine plastics in gaining or donating electrons, which compromises the electrical performance of the fabricated f-TENG. Herein, this study demonstrates a simple solution-casting based physical doping strategy to develop high-performance triboelectric elastomer films and f-TENGs. Styrenic elastomer film was physically doped using various fluorines or amines. The doped elastomer films were further printed with flexible silver electrodes and then were used to construct a wide spectrum of f-TENGs. Remarkably, at vertical contact-separation mode, the f-TENG fabricated from the trifluoroacetic acid and polystyrene-bound triazabicyclodecene respectively doped films generated up to 385 V voltage with maximum 39.7 μA/cm2 current density and 15.1 mW/cm2 power density. This f-TENG also effectively converted a wide range of low-frequency body motions (run, walk, finger bending, throat vibration, and heart electrical impulse) to electricity. This f-TENG enables to develop self-powered real-time mechanoelectric sensor for recovering voice and monitoring heart rate. The results also indicated that trifluoroacetic acid was generally more effective than other fluorines in enhancing the electron-accepting ability of styrenic elastomer film and polystyrene-bound triazabicyclodecene was more effective than other amines in enhancing the electron-donating ability of styrenic elastomer film.