There are a lot of vibrational energies, which are low frequency, multidirectional, and broadband, in the nature. This creates difficulties for devices that aim at harvesting vibration energy. Here, we present a liquid-metal-based freestanding triboelectric generator (LM-FTG) for vibration energy harvesting. In this device, the fluidity of liquid is used to increase sensitivity to vibration for better low-frequency response and multidirectional vibration energy harvesting capability. The freestanding power generation mode is able to increase power generation stability. Experiments show that the bandwidth of LM-FTG can almost cover the entire sweep frequency range, and a 10 μF capacitor can be charged to 6.46 V at 7.5 Hz in 60 s by LM-FTG. In particular, 100 LEDs are illuminated in the low-frequency environmental experiment successfully. The proposed LM-FTG can work in low frequency with large working bandwidth, which provides an effective method for energy harvesting of low-frequency and multidirectional vibrations.
A Liquid-Metal-Based Freestanding Triboelectric Generator for Low-Frequency and Multidirectional Vibration