In the past few years, triboelectric nanogenerator (TENG) technology has been proven to effectively harvest low-frequency mechanical energy. To expand the application scope, we tried to explore the upper limit of TENG’s working frequency.

At low frequency, TENG is dominated by the external mechanical force and not sensitive to the device itself. On the contrary, the resonant frequency of the device will have a significant effect on the TENG’s output performance at high frequency. In addition, the resonant frequency of the TENG device is extremely sensitive to the structural dimensions of the device, thus the resonant frequency of the device has to be taken into consideration. However, current TENG fabrication methods are mostly based on handcrafted methods and can hardly achieve good reproducibility. 

To address this problem, we integrated the Micro-Electro-Mechanical Systems (MEMS) technology with TENG and designed a triboelectric ultrasonic device, which has the working frequency of 1 MHz. With MEMS technology, the device’s structural dimensions can be easily controlled, so that the resonant frequency of the device can match the desired working frequency. Another important advantage of MEMS technology is to dramatically improve the miniaturization and chip integration of triboelectric nanogenerator. 

If you are interested in our work, please refer to the paper published in Nature Communications following the link: https://www.nature.com/articles/s41467-020-17842-w.