Glycine-based piezoelectric nanogenerators for mechanodynamic tissue regeneration

The rapid growth of wearable and implantable electronics has led to a search for power systems that are safe for the body and can disappear when no longer needed. Glycine-based piezoelectric nanogenerators (PENGs) have become a leading option in this area because they naturally generate electricity from movement, have a simple structure, and are fully biodegradable. This review provides a detailed look at glycine PENGs, moving from basic crystal science to their use in tissue engineering. We first look at how glycine turns mechanical energy into electricity, focusing on its different crystal forms and how they are built into structures such as tiny tubes, reinforced materials, and fibrous materials. A major part of this discussion is how these devices can both sense body movement and actively help tissues heal. Beyond just collecting energy, we explain how glycine itself helps the body, such as by controlling immune responses and protecting cells. We also study how the mechanodynamic processes of these devices, specifically how their physical motion and resulting electricity guide cell growth and regulate mechanotransduction signaling. Finally, we show examples of how this technology helps regenerate nerves, muscles, skin, and bone, while discussing the practical steps needed to ensure their biocompatibility in the body. This review positions glycine PENGs as one of the key technologies for future self-powered medical devices for tissue healing and regenerative purposes.