Skin-conformal BaTiO3/ecoflex-based piezoelectric nanogenerator for self-powered human motion monitoring

Abstract Skin-conformability and lead-free piezo-materials are important for piezoelectric nanogenerator (PENG)-based wearable electronics. Here, a skin-conformal BaTiO3/Ecoflex-based PENG was fabricated by incorporating BaTiO3 particles into an Ecoflex matrix. Due to the inherent elongation of Ecoflex, appropriate thickness of the BTO&Ecoflex film, and optimized polarization, the fabricated device exhibited suitable skin-conformability and high output performance. The output voltage/current reached 8.9 V/49.7 nA with a load resistance of 200 MΩ (effective area: 1.0 cm × 1.0 cm). Due to its suitable skin-conformability and high output performance, the device can be attached to an elbow as an active sensor for the monitoring of joints. In this way, it is promising for medical research and human-machine interaction (HMI) applications. This study is significant for the development of skin-conformal lead-free PENGs.