Hybrid enhancement effect of structural and material properties of the triboelectric generator on its performance in integrated energy harvester

Abstract

A wind energy harvester (WEH) comprising a coaxial electromagnetic generator (EMG) and a triboelectric nanogenerator (TENG) is proposed to achieve an energy-autonomous closed loop that can harvest widely untapped energy sources for unattended monitoring systems in desolate regions. Energy conversion in the EMG from wind to electrical energy is implemented via the cyclic fixed-axis rotation, whereas that in the TENG is controlled by reciprocating translation driven by the coaxial rotation of the contact-separation structure. However, it is essential, albeit difficult, for TENG to generate a major portion of the wind energy-based electricity by improving the secondary transformation efficiency and reducing wear abrasion. Here, an arrayed contact-separation structure is fabricated with doped and surface-modified friction silicone rubber, large-area arc-shaped substrates, and a Reuleaux triangle plate-cam with local freedom. When the WEH works in one cycle, the TENG runs 12 times. Compared with the single contact-separation structure, the modified friction material significantly increases the output performance of the hybrid enhanced TENG by 104 % and the arrayed cam structure triples the output energy of TENG in a cycle. The maximum output power of the WEH is 54.78 mW at 90 rpm, to which the EMG and TENG contribute approximately 51.57 mW and 3.21 mW, respectively. The share of TENG output energy rivals the results induced by sliding mode TENG in those hybrid energy harvesters of current research. Furthermore, a WEH with an enhanced TENG is experimentally demonstrated by simulating earthquake, fire, and wind speed monitoring. The results indicate the immense potential of the proposed WEH in terms of power supply capability and long-term operation reliability.