Double-induced-mode integrated triboelectric nanogenerator based on spring steel to maximize space utilization

Integrated multilayered triboelectric nanogenerators (TENGs) are an efficient approach to solve the insufficient energy problem caused by a single-layered TENG for achieving high output power density. However, most integrated multilayered TENGs have a relatively large volume. Here, a double-induced-mode integrated triboelectric nanogenerator (DI-TENG) based on spring steel plates is presented as a cost-effective, simple, and high-performance device for ambient vibration energy harvesting. The unique stackable rhombus structure, in which spring steel plates act both as skeletons and as electrodes, can enhance the output performance and maximize space utilization. The DI-TENG with five repeated units in a volume of 12 cm × 5 cm × 0.4 cm can generate a short-circuit current of 51 μA and can transfer charges of 1.25 μC in a half period. The contrast experiment is conducted systematically and the results have proved that the DI-TENG has a great advantage over the single-induced-mode TENG (SI-TENG) with only one side of a friction layer on its electrode. Besides, the DI-TENG can easily power a commercial calculator and can be used as a door switch sensor.