New cambered-surface based drip generator: A drop of water generates 50 µA current without pre-charging.

Triboelectricity has demonstrated bright application prospects in the field of blue energy harvesting. However, the low output efficiency of solid-liquid triboelectricity hinders its practical application. This paper proposed a high-efficiency drip nanogenerator with a cambered surface based on the brachistochrone curve principle. In this nanogenerator, a drop of water can achieve an output current of 50 µA and an output voltage of 137 V without pre-charging. The cambered-surface structured triboelectric nanogenerator (C-TENG) enhances the short-circuit current by 30 times compared to the traditional TENG based on flat-surface structure (F-TENG). The output power of C-TENG reaches up to 1.875 mW at the central angle of 60°. The Simcenter STAR-CCM+ Viewer software is utilized to simulate the falling process of water droplets and the dynamics to explain the difference in the falling process of central angle structures at different central angles. The C-TENG characteristics ensure improved energy collection efficiency. Therefore, it is used to design a new droplet energy collection structure for rain energy harvesting. C-TENG has a more significant lighting effect than F-TENG. This new drip generator demonstrates remarkable efficiency in collecting various water energies in nature and has potential applications in device power supply and self-powered sensing. In this work, we creatively designed a cambered-surface based TENG (CS-TENG) with a flexible PTFE filter membrane attached to the inner wall of a cambered-surface device for high drop energy collection efficiency without pre-charging. In this cambered surface contact mode, the CS-TENG has a higher output with short-circuit current of 50 µA than that of the flat-surface structure TENG (in prior investigations most of the water droplets TENG developed were based on the flat-surface structure), with the triboelectric current enhanced dozens of times. This study provides a novel design concept for improving water drop power generation. [Display omitted] • A new droplet TENG (CS-TENG) based on cambered surface has been designed and developed. • A droplet of water can generate power of 50 µA and 137 V on CS-TENG without pre-charging. • It is a simple and efficient development of TENG for harvesting raindrop energy. • A new approach to enhance triboelectric output using simple materials. [ABSTRACT FROM AUTHOR]