Flexible staircase triboelectric nanogenerator for motion monitoring and gesture recognition

Triboelectric sensors, which are used in human-computer interaction and condition monitoring, have attracted tremendous scientific interest owing to their broad applicability, high energy utilization, and high accuracy detection. Here, a staircase-style flexible triboelectric sensor assembled by the antimony-doped tin oxide (ATO) functionalized flexible polyvinylidene fluoride polymer (PVDF) composite film is first proposed for gesture recognition and human motion detection. The modified composite film ATO/PVDF with high polarization and large permittivity improves the electrical output of the triboelectric nanogenerator (TENG). Compared with the pure PVDF, the modified PVDF film-based TENG could substantially enhance power density by 11.5 times. The peak voltage and power density of the flexible staircase-style TENG achieve 70 V and 0.58 W/m2, respectively. The flexible triboelectric sensor can be attached to the finger or wrist to obtain movement information through positive/negative signals. A set of rules between gestures and corresponding letters and numbers is defined and a gesture recognition system using deep learning algorithms is developed. The flexible triboelectric sensor realizes human body part bending, gesture, and motion state recognition, offering potential solutions and novel possibilities in smart sensing and human-computer interaction.