High-powered superhydrophobic pyroelectric generator via droplet impact

Recent studies on water-based pyroelectric generators (PEGs), which convert thermal energy to electrical energy, have focused on different operational modes like water evaporation, water stream, and droplet sliding. However, the development of sustainable, high-powered generators and comprehensive theoretical models has been limited. In response, our research introduces a droplet-based superhydrophobic pyroelectric generator (S-DPEG), exploiting the characteristics of lead magnesium niobate-lead titanate (PMN-0.3PT) coated with titanium dioxide nanoparticles. We analyzed power density by considering the phase transient temperature that maximizes the pyroelectric coefficient of PMN-0.3PT, testing various Weber numbers and droplet diameters within a moderate operating temperature range of 40°C to 80°C. Considering the dynamic characteristics of water droplet on superhydrophobic surfaces, we suggest a peak current model that can accurately predict the peak current within ∼15 % of error. Also, the maximum power density of 54.5 μW/cm² at a droplet diameter of 3.6 mm and a temperature of 80°C, a noteworthy improvement over 3 times higher than previous water-based PEGs. Our results enhance the understanding of the pyroelectric effect coupled with drop impact dynamics and outline novel strategies for designing high-performance water-based PEGs.