Minwoo Kim, Younghun Noh, Hyunsoo Kim, Yongwoo Jang
Self-powered sensor technologies are receiving increasing attention owing to their ability to operate independently without the need for external batteries or power supplies. This autonomy enables continuous and real-time monitoring in various applications. Carbon nanotubes (CNTs) are particularly promising as electrode materials and energy-harvesting components, owing to their excellent electrical conductivity, mechanical robustness, and tunable surface properties. This review provides a concise overview and critical perspectives on recent progress in CNT-based self-powered sensors, focusing on their structural designs, operating mechanisms, and application areas. The sensors are classified according to their practical application environments, including environmental, wearable, and implantable applications, rather than by their energy-harvesting mechanisms or detection targets. Furthermore, current critical challenges, such as durability, scalable fabrication, and in vivo validation, which must be solved to achieve fully autonomous CNT-based sensors for healthcare and environmental monitoring, are discussed. This review underscores the pivotal role of CNT-based self-powered sensors in driving next-generation autonomous monitoring technologies and offers insights for the implementation of such sensors in practical biomedical and environmental applications.