MXene-Based Piezoelectric and Triboelectric Energy Harvesters for Personalized Monitoring and Therapeutics

MXenes, a rapidly expanding family of two-dimensional transition-metal carbides and nitrides, have emerged as a key material of self-powered wearable electronics and therapeutics owing to their metallic conductivity, mechanical flexibility, and highly tunable surface chemistry. Their integration into piezoelectric nanogenerators and triboelectric nanogenerators (PENGs and TENGs) has substantially advanced mechanical-to-electrical energy conversion in flexible, skin-conformal devices. This review critically examines recent progress in MXene-enabled nanogenerators, covering material synthesis, device architectures, charge-generation mechanisms, and system-level integration. Emphasis is placed on emerging MXene-based composites, including hydrogels, aerogels, nanofibers, and smart textiles, that synergistically integrate energy harvesting, sensing, and mechanical robustness for continuous physiological monitoring, human-machine interfaces, sports analytics, wearable therapeutics and in vivo applications. Key challenges limiting practical deployment, such as oxidation instability, mechanical fatigue, biocompatibility, and scalable manufacturing, are systematically analyzed alongside state-of-the-art mitigation strategies. Finally, future perspectives are outlined, highlighting the convergence of MXene nanogenerators with artificial intelligence, the Internet of Things, and sustainable materials systems to enable autonomous, intelligent, and next-generation, personalized monitoring and therapeutic technologies.