Control of crystal orientation for enhanced triboelectric nanogenerator design

Triboelectric nanogenerators (TENGs) have shown promise in converting mechanical energy into electrical energy and are gaining attention in energy harvesting for self-powered sensors. Although extensive strategies have been explored to enhance TENG performance through new materials development and chemical/physical modification, the influence of crystal orientation has been mostly overlooked. In this work, we investigated the effect of crystal orientation on TENG output using [012] and [001]-oriented single crystalline alumina as a triboelectric material. Our comprehensive characterization and analysis show that the [001]-oriented alumina is a more positive triboelectric material than the [012]-oriented alumina. We also analyzed the root cause of the enhanced TENG performance. Our findings emphasize the importance of crystal orientation in TENG design and provide insights into the underlying mechanism governing this triboelectrification effect.