Fig. 6.

Applications of 3DP in sustainable energy generation (a) 3D-printed phononic crystal lens for elastic wave energy harvesting (b) 3D-printed hybrid coaxial TENG inspired by a crank engine (HC-TENG) (c) Bidirectional gear transmission-based TENG fabricated through 3D printing (d) 3D printed miniature electromagnetic energy harvesters driven by airflow (e) All 3D printed grating disk type TENG (f) ship-shaped hybridized nanogenerator (SHNG) (g) triboelectric-electromagnetic rotating gyro structured blue energy harvester, All the devices are fabricated using 3D printed parts (h) Solar energy harvester with a 3-D printed package (i) 3D printed solar energy trees (Image credits: alternative-energy-news.info/) (Images are re-used with the permission of Elsevier).4