A highly efficient self-powered variable impendence system

As an efficient mechanical energy harvester, the triboelectric-electromagnetic hybrid generator (TEHG) stands as a cornerstone in self-powered systems. Nevertheless, significant impedance disparities between triboelectric nanogenerators (TENGs) and electromagnetic generators (EMGs) often hamper systems’ energy utilization efficiency, attributed to impedance mismatch at the load. Here, a variable impedance strategy is proposed, aimed at maximizing the utilization of mechanical energies converted by TEHG. This approach capitalizes on electronic components with dynamic impedance from GΩ to kΩ in response to OFF-ON state transitions, thus matching the impedance of TENG and EMG. Experimentally, an ultraviolent gas discharge tube (UV-GDT) is integrated into the self-powered variable impedance system. Operated at 240 rpm, the TEHG-driven UV-GDT extracts energy amounting to 1304.27 mJ with an 87.5 % utilization efficiency. These metrics outperform the situation where UV-GDT is individually powered by either EMG (0 mJ, 0 %) or TENG (18.24 mJ, 60.7 %). Furthermore, the mechanical energy-activated UV system demonstrates promise for sterilization, curing, and photo-chemical reactions. This variable impedance strategy resolves the impendence mismatch between TEHG and load, more importantly, provides a valuable guideline for developing hybrid generator systems with enhanced energy utilization efficiency.