High-temperature operatable triboelectric nanogenerator using microdome-patterned polyimide for self-powered sensors

Renewable energy has received attention all around the world to deal with environmental pollution and energy crisis. Triboelectric nanogenerators (TENGs) has emerged as a promising way to transition to green energy. However, typical TENGs exhibit inferior output, low heat-resistance, and low durability. Polyimide is one of the most mechanically strong and thermally stable thermoplastics, and it could be used to overcome the drawbacks of TENGs. Thus, polyimide has become a promising building material for robust TENGs. Herein, we have rationally designed and created an efficient polyimide tribo-surface with customizable non-close packed microdome arrays (md-PI) to assemble TENGs (md-TENG) for harvesting windmill energy and vibration from engine even with hot air and high humidity surrounding. The md-TENG fabricated with md-PI and flat aluminum can generate an exceptional output power of 1.42 W.m(-2). This is about 29 times higher than the output of a TENG using a normal flat PI. Additional FEM simulations are performed to analyze the relationship between the contact area and mechanical stresses on the md-PI. Moreover, the md-TENG possesses outstanding durability of over 16,000 cycles of contact-separation, and the device exhibits better outputs at elevated temperature. The newly developed md-TENG achieves excellent thermal stability and durability as well as superior electrical output, which are essential to expand the practical applications of TENG. To illustrate the strengths of md-TENG, we demonstrated a wireless communication self-powered IoT humidity sensor and a vibration TENG sensor at high ambient air temperature in the engine compartment of a car.