High-Performance Petal-Shaped Triboelectric Nanogenerator for Monitoring Rotational Speed Variations in Downhole Equipment

Traditional methods for measuring the rotational speed of downhole equipment require various external power sources. This study introduces a high-performance petal-shaped triboelectric nanogenerator (PS-TENG) for monitoring rotational speed variations in downhole equipment. The PS-TENG does not require an external power supply, and through the application of Fourier and Hilbert-Huang transforms, it enables real-time monitoring of instantaneous rotational speed in downhole machinery under both constant and variable speed conditions. Moreover, the PS-TENG exhibits excellent power generation performance. With power management circuits (PMCs), the PS-TENG can charge a 100-<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu $ </tex-math></inline-formula>F capacitor to 10 V in just 4 s at a rotational speed of 800 r/min. It can also recharge a 150-mAh lithium battery from 1.6 to 2 V within 280 s. Notably, the PS-TENG demonstrates favorable adaptability to high-humidity environments in downhole settings, and due to its soft-contact motion form, the PS-TENG has a lifespan that meets the requirements of downhole applications. In conclusion, the PS-TENG offers an innovative and efficient solution for self-powered sensing and real-time rotational speed monitoring in downhole applications.