Elastic-Arch Lateral-Pressing Hybrid Nanogenerator for Blue Energy Harvesting: Achieving Self-Powered Seawater Desalination

The development of efficient and reliable blue energy harvesting technologies is crucial for addressing the dual shortages of energy and fresh water in remote regions. Herein, we report an elastic-arch lateral-pressing hybrid nanogenerator (EL-HNG), which integrates a contact-separation mode triboelectric nanogenerator (TENG) and a vertical-motion electromagnetic generator (EMG) within a compact, fully enclosed body for efficient water wave energy harvesting. The core of the design is an elastic arch structure fabricated from Kapton, which ingeniously decouples the vertical vibrations induced by waves into a contact-separation motion for the TENG and relative motion between the magnet and coil for the EMG. Through systematic optimization of key structural parameters, such as the arch length and the central mass, the device's performance was significantly improved. Under optimal operating conditions of 2.0 Hz and 30 mm amplitude, the TENG module delivered a peak power of approximately 10 mW at a 5 MΩ load, while the EMG module produced approximately 3.5 mW at a 60 Ω load. By employing a power management module, the energy from both sources was effectively coupled and stored. Ultimately, the EL-HNG system successfully served as a standalone power source to drive an electrodialysis unit, reducing the conductivity of a 0.5 mol/L NaCl solution from 52.4 mS/cm to below the standard for drinking water within 24 h. This work provides a valuable paradigm for the development of next-generation, high-performance blue energy conversion devices and for the construction of self-sufficient offshore resource-support platforms.