Sea State Adaptation Enhances Power Output of Triboelectric Nanogenerators for Tailored Ocean Wave Energy Harvesting

To face the climate crisis, sustainable energy harvesting systems are critical. Triboelectric nanogenerators (TENGs) are in the spotlight for their inexpensive and non-toxic manufacturing, allied with their excellence in harvesting low frequency vibrations. Ocean waves are a prime example of energy source in this regime, and their successful harvesting with TENGs has been widely demonstrated. However, the influence of wave characteristics on the power output of these devices has so far been overlooked. Here, the existence of a moving element that acts upon the nanogenerators is explored both with multiphysics simulations and an extensive experimental characterization under different operating conditions. It is shown how different sea states modulate the moving body velocity, and how the generator can be optimized to harvest waves with specific characteristics. In parallel, it is demonstrated that the power output is proportional to the contacting triboelectric layers velocity. Optimizing the dynamics of the moving body provides an efficient path to intentionally tune the contacting triboelectric layers velocity, and therefore improve the output of TENGs and their suitability to harvest specific sea states. In the field of ocean wave energy harvesting, a correlation between wave parameters and electric output of triboelectric nanogenerators (TENGs) is often overlooked. It is shown that, depending on the wave characteristics, a moving body acting upon the generators leads to enhanced contacting layers velocity and power output. This characterization is supported by multiphysics simulations, opening a new path to design optimized TENGs for specific sea states.image