This study presents the design and analysis of a thermal energy harvester that integrates a thermoacoustic engine (TAE) with a honeycomb-structured triboelectric nanogenerator (H-TENG), referred to as TAEH-TENG. This design is specifically developed to demonstrate the potential of thermal energy harvesting for low-power Internet of Things (IoT) applications. By leveraging the high energy conversion efficiency of TAEs and the exceptional robustness of H-TENGs, this harvester overcomes the limitations of traditional designs, which often involve complex or costly components. The experimental results revealed the oscillation characteristics of the TAEH-TENG: by utilizing a hot heat exchanger (HHE) with a length of 10 cm, the system can sustain oscillation over 150–350 °C. Furthermore, the harvester is capable of generating an open-circuit voltage of 25 V, an RMS current of 0.98 μA, and a peak power output of 0.48 mW, representing the highest power output achieved to date in comparison to previous studies. To further showcase the harvester's capability, an ultra-low-power IoT node was developed. Solely powered by the TAEH-TENG, the IoT node achieved cold-start, conducted in situ temperature measurement five times, and transmitted the data via Bluetooth within 120 s. This study not only showcases a fully self-powered IoT application but, more importantly, significantly advances the technology beyond the previous limitations faced by thermoacoustic and triboelectric integrations. By demonstrating the capability to power an ultra-low-power IoT node, this research highlights the TAEH-TENG's potential for practical, real-world energy solutions, marking a significant milestone in the deployment of heat-powered IoT applications.

Ocean wave energy represents a promising renewable resource with high energy density. However, its inherently low-frequency, stochastic, and multi-directional characteristics pose significant challenges for efficient energy harvesting. In this study, a pendulum-type counter-rotating electromagnetic generator (CREMG) is proposed to address these issues. The CREMG integrates a planetary gear system and dual one-way bearings. The one-way bearings convert irregular bidirectional pendulum motion into unidirectional rotation, and the planetary gear system amplifies the rotation by a 1:4 transmission ratio, collectively enhancing energy conversion efficiency. Experimental results show that the proposed CREMG delivers a maximum RMS power of 304.46 mW at an optimal load resistance of 5000 Ω, with a 1 F capacitor charged to 3.44 V within 400 s, corresponding to a harvested energy of 5.92 J. To further validate its practical potential, the CREMG was used to power a customized wireless sensing circuit for temperature and humidity monitoring under random excitations. Overall, this work demonstrates a compact and efficient solution for low-frequency wave energy harvesting, offering a viable pathway toward self-powered marine sensing and autonomous ocean monitoring systems.

Continuous high‐frequency data acquisition is critical for advanced structural monitoring and data‐driven systems, yet remains limited by the insufficient energy budget of self‐powered sensing. Existing solutions are largely confined to intermittent operation or low sampling rates, as sustained high‐throughput sensing imposes prohibitive power demands. In this paper, we propose a full‐stack self‐powered sensing framework that overcomes this barrier via a synergistic electromechanical–circuit–sensing co‐design. The system integrates a quasi‐zero‐stiffness (QZS) piezoelectric energy harvester (PEH) for efficient weak‐excitation energy harvesting, a synchronous electric charge extraction (SECE) interface for impedance‐decoupled energy extraction, and an energy‐aware sensing module for efficient high‐frequency operation. This integrated architecture enables sustained real‐time waveform acquisition at a continuous sampling rate of approximately 48 Sa/s, achieving an unprecedented level of continuous high‐frequency sensing compared to existing self‐powered systems and far exceeding the limitations of intermittent operation. The system can operate using energy harvested from a single piezoelectric transducer, while maintaining stable performance over a frequency range of 6–8 Hz at a low excitation level of 0.14 g. By transforming self‐powered sensing from discrete, low‐rate measurements to continuous real‐time monitoring, this work establishes a new paradigm for fully energy‐autonomous sensing and lays the foundation for scalable, infrastructure‐level deployment of intelligent monitoring systems.

High-fidelity sensing remains highly challenging in self-powered systems, as the limited power of energy harvesters constrains data acquisition and transmission. In this work, we present a wireless, intelligent, self-powered environmental node (WISE-Node) that simultaneously harvests energy and collects sensing information from ambient vibrations. Its multi-contact triboelectric vibration energy harvester (MC-TVEH) achieves an ultra-wide bandwidth of 10–300 Hz, delivering peak and RMS power densities of 13.42 kW/m ³ and 1.73 kW/m ³ , respectively. The WISE-Node also functions as a broadband sensor, accurately tracking excitation frequencies via FFT analysis ( R ² = 0.9997 across 3–10,000 Hz). Using a Random Forest classifier on the acquired data, the WISE-Node identifies flange conditions with 99.38% accuracy. Field tests on marine engines and generators validate its robust performance, achieving a cold start in just 28.8 s and maintaining fully self-powered 1000 Hz sampling and stable wireless transmission. These results highlight the proposed WISE-Node’s strong potential for self-sustained high-fidelity sensing, thereby advancing next-generation battery-free industrial IoT and digital twin technologies.