Self-Sustaining Sensing Systems: Integration Strategies and Signal-Power Matching in Energy-Harvesting Electronics

Self-sustaining sensing systems that simultaneously harvest ambient energy and perform real-time signal acquisition are emerging as key technologies for wearable electronics, intelligent Internet-of-Things platforms, and autonomous edge systems. Despite rapid advances in individual energy harvesters and self-powered sensors, a unified framework connecting device integration and operational strategy remains underdeveloped. In this review, we present systematic integration strategies and signal-power matching principles for energy harvester-integrated sensing systems. First, energy harvester-integrated platforms are categorized into three representative architectures: co-packaged devices, monolithically integrated devices, and co-functional devices, according to the physical and functional relationship between the harvester and sensing unit. Their structural characteristics, operational advantages, and representative implementations across photovoltaic, thermoelectric, triboelectric, and piezoelectric systems are comparatively discussed. Beyond structural integration, we further classify operational paradigms into always-on sensing, event-driven sensing, and multi-modal sensing based on the temporal characteristics of sensed signals and harvested power profiles. This framework clarifies how harvested energy is distributed across sensing, storage, processing, and wireless communication pathways in practical autonomous systems. Key challenges and future opportunities toward scalable self-sustaining intelligent sensing platforms are discussed.