Two-dimensional Hexagonal Boron Nitride Nanosheet–Polycarbonate Composite Ink-Based Printed Flexible Triboelectric Nanogenerator for Scavenging Mechanical Energy

Abstract

In the modern world, the rapid depletion of conventional energy sources demands urgent exploration of materials and methods for clean, efficient, and sustainable energy production. As a mechanical energy harvester, triboelectric nanogenerators (TENGs) have been investigated extensively in recent years due to their high power output, superior energy conversion efficiency, low cost, and ease of manufacturing. Herein, a high-performance flexible TENG is developed based on 2D-hexagonal boron nitride nanosheet (BNNS) ink printed on Mylar substrates as a triboelectric contact layer. The thixotropy of the BNNS dispersion was controlled by polycarbonate (PC) and other suitable organic additives. Further, the formulation was modified into a versatile ink (BN-PC ink) suited for screen printing. Remarkably, the flexible screen-printed TENG (FS-TENG) fabricated using BN-PC ink as a tribonegative material, paired with the printed polyvinylpyrrolidone (PVP) on Mylar as a tribopositive material, demonstrated a very high voltage of ∼800 V and a short-circuit current density of ∼0.78 mA/m2, respectively, under an actuating force of ∼10 N with 5 Hz frequency. The FS-TENG has shown an impressive power density of ∼1.36 W m–2 at 200 MΩ resistive load, which is ∼7 times higher than that of the TENG without BNNSs. Further, the fabricated FS-TENG device is demonstrated for powering electronic gadgets such as digital thermometers, calculators, and light-emitting diodes (LEDs) with a mere finger-tapping force of ∼5 N.