Ferro-electricity of dry cortical bone

A long-lasting power source is crucial for a sustainable operation of implanted medical devices. However, the battery-powered medical electronic devices are at risk of failure due to insufficient power energy. As an emerging energy conversion technologies, the Nanogenerators (NG) that could convert micro-/nano-scale mechanical energy into electricity based on the mechanism of piezoelectricity and triboelectricity exhibited great promise for biomedical applications, owning to the simple configuration, high efficiency, decent electrical output, biomimetic property as well as excellent biocompatibility. In this manuscript, the recent representative developments of NGs in biomedical applications are reviewed. Fundamentals, such as working mechanisms underneath different NG prototypes are discussed, which is followed by intriguing attempts to implement NG in specific biomedical fields(e.g., power source for implantable medical devices, therapeutic electric stimulator, cardiovascular, skin injury, bone tissue etc.) are introduced and analyzed. This manuscript ends up with subsection summarizing existed challenges while providing potential solutions for future NG developments in biomedical engineering.