Self-powered real-time fall alarm microsystem based on reconfigurable paper-like piezoelectric nanogenerator

Piezoelectric nanogenerators (PENGs) have emerged as a promising technology for ambient energy harvesting, serving as robust power sources and enabling self-powered electronics. These devices hold great potential in the construction of intelligent medical monitoring systems owing to their unique ability to integrate self-powering capabilities with various functionalities. While numerous high-performance PENGs have been proposed and applied in the field of sensing, the focus has primarily been on device sensitivity and stability, neglecting another crucial characteristic: reconfigurability. Here, a reconfigurable paper-like PENG based on the material properties of the piezoelectric functional layer was developed. The polarization strategy of barium titanate (BTO) and cellulose nanofibril (CNF) piezoelectric film, the feasibility of reconfigurability and biodegradability of piezoelectric functional materials, and the effects of packaging on the electrical output of the device were comprehensively investigated through experimental measurements. Results revealed that 25 wt% BTO content in the functional film yields the highest electrical output of the PENG, and this functional film maintains a stable output even after multiple reconfigurations. Furthermore, the BTO-CNF piezoelectric film provides PENGs with lower internal resistance, enabling compact integration with conventional circuits and showcasing great potential in the field of self-powered smart microsystems, particularly those requiring remarkable reconfigurable properties. Consequently, this study successfully demonstrated an intelligent monitoring microsystem for fall alarms, which is self-powered and flexible.