Metal-organic framework and molybdenum oxide doped highly negative hybridized triboelectric material for self-powered and continuous monitoring of biosignals

Abstract

Self-powered wearable sensors have broad applications in biomotion and personal healthcare monitoring. However, poor sensing abilities, low power outputs, and limited material selection have significantly constrained their advancement. Herein, a novel orthorhombic molybdenum oxide (α-MoO3) nanowire-doped hybridized metal–organic framework (MOF)-525@silicone@α-MoO3 was prepared and used as a highly negative triboelectric material to construct a triboelectric nanogenerator (TENG) for the first time. The prepared MOF-525@α-MoO3 enhanced the capacitance and provided strong charge accumulation owing to the synergistic effect between the heterostructure network and improved dielectric properties of the nanocomposite. In addition, hybridized tribo-materials increased the charge trapping and charge-inducing ability by including a large internal surface area; thus, they were able to generate a higher negative charge. With the assistance of microstructure modification using a three-dimensional printed template, the resulting TENG exhibited ultrahigh sensitivity (105.18 V/kPa) and power density (18.38 W/m2). TENG can power small electronics as a renewable energy source. A self-powered wearable biomotion sensor based on a TENG was developed for real-time, noninvasive skin-level biomotion sensing and joint-associated activity monitoring. Furthermore, an intelligent respiration and pulse monitoring system was demonstrated using an ultrahigh-stretchability (250 %) TENG. By combining the signal processing unit with TENG, we demonstrated the practical advantages of the device in sensing electromyography signals via smartphone applications and predicting their extensive use in biomedical and personal healthcare.